PICREF-3 OVERVIEW Reference Design provides cost effective circui

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PICREF-3 OVERVIEW Reference Design provides cost effective circui

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PICREF-3
PICREF-3 OVERVIEW
Reference Design provides cost effective circuit capable monitoring displaying power energy consumption worldwide power mains 264V range. PIC16C924 microcontroller shows that real-time events sampling voltage current waveforms interleaved with power energy calculations. measurements calculations performed once second. current waveforms measured linear resistive inductive loads non-linear switching power supplies. current waveform sampled during positive current cycle with waveform symmetry assumed between positive negative cycles (valid measured waveforms). hardware method full cycle current measurements firmware methods complex current waveform shapes provided Design Modifications section.
Watt-Hour Meter Reference Design
PICREF-3 Watt-Hour Meter (WHM) Reference Design shows mixed signal microcontroller power measurement application. traditional sensor signal processing chain consisting sensor, signal conditioning electronics, converter microcontroller abbreviated mixed signal microcontroller with on-board converter. mixed signal microcontroller used Microchip PIC16C924. This microcontroller five channels, which used digitize voltage current signals. microcontroller features pulse width modulation (PWM) direct liquid crystal display (LCD) drive utilized further reduce cost parts count. output feature used with single pole filter provide comparator reference with bits resolution. direct drive used drive 8-digit, 7-segment LCD.
PICREF-3 FEATURES
Accepts polarized unpolarized worldwide power mains. Measures displays Voltage (90V 264V), Load Current Power Factor. Measures power line frequency Hz). Calculates Watts, Watt-Hrs cumulative Watt-Hrs displays these values, well frequency time. True measurements. Firmware control triac load switch on/off state. Real time clock during power-saving sleep mode. Hibernate mode save battery life during storage. Battery back-up microcontroller.
MICROCONTOLLER BENEFITS
PIC16C924 microcontroller power meter offers following advantages: Real-Time Electrical Measurement Power/Energy Calculations Direct Drive Present Time Total Watt-Hours (Whr) Maximum Cumulative Demand Customization Quick Time-to-Market
INFORMATION CONTAINED THIS PUBLICATION INTENDED THROUGH SUGGESTION ONLY SUPERSEDED UPDATES. REPRESENTATION WARRANTY GIVEN LIABILITY ASSUMED MICROCHIP TECHNOLOGY INC. WITH RESPECT ACCURACY SUCH INFORMATION, INFRINGEMENT PATENTS ARISING FROM SUCH OTHERWISE. RESPONSIBILITY EACH USER ENSURE THAT EACH WATT-HOUR METER ADEQUATELY DESIGNED, SAFE, COMPATIBLE WITH CONDITIONS ENCOUNTERED DURING USE. "TYPICAL" PARAMETERS VARY DIFFERENT APPLICATIONS. OPERATING PARAMETERS, INCLUDING "TYPICALS", MUST VALIDATED EACH CUSTOMER APPLICATION CUSTOMER'S TECHNICAL EXPERTS. MICROCHIP'S PRODUCTS CRITICAL COMPONENTS LIFE SUPPORT SYSTEMS AUTHORIZED EXCEPT WITH EXPRESS WRITTEN APPROVAL MICROCHIP. LICENSES CONVEYED, IMPLICITLY OTHERWISE, UNDER INTELLECTUAL PROPERTY RIGHTS.
1997 Microchip Technology Inc.
Preliminary
DS30452A-page
PICREF-3
TABLE CONTENTS
System Overview.3 Hardware Overview Firmware Overview.8 Firmware Detail.16 Test Results.21 Calibration.21 Power Theory Design Modifications.23 System Specifications.25 Schematics Firmware Listing Layout Drawing.39 Bill Materials (BOM) Watt-Hour Meter Demo Unit.45
ACKNOWLEDGMENTS
Hardware Design Firmware Development: Dennis Coleman, Applications Engineer, Microchip Technology, Inc. [email protected] Documentation: Beth McLoughlin, Applications Engineer, Microchip Technology, Inc.
DS30452A-page
Preliminary
1997 Microchip Technology Inc.
PICREF-3
System Overview
PICREF-3 Reference Design shows develop cost-effective watt-hour meter (WHM). Using PIC16C924 microcontroller, performs power line measurements, followed power energy calculations, once second. System Specifications found Appendix PICREF-3 accept worldwide power mains calibrated both. Worldwide power mains either polarized unpolarized. polarized power main grounded neutral connection. Reversal line neutral polarized power main will create power line fault. unpolarized power main does have grounded neutral connection. Therefore, line neutral connected random without causing power line fault. Countries using polarized power mains include Australia, United Kingdom, Ireland, Denmark, India, Israel, Japan Switzerland. Countries using unpolarized power mains include Germany, Austria, Norway, Sweden, France, Finland, Netherlands, Belgium Italy. PICREF-3 limited measuring maximum current Amps. However, residential current loads Amps maximum. Design Modifications hardware design changes scale meter 200A loads. Power line voltage (90V 264V) sensed high voltage electronics (Figure Balanced input voltage current signals then provided Small Signal Analog/Digital Sense Electronics input into PIC16C924. PIC16C924 uses analog/digital voltage sense analog/digital current sense calculate power energy consumption load. microcontroller then displays these calculations 8-digit according user pushbutton input. PIC16C924 controls on/off state triac control circuit. triac control circuit applies current power triac gate effect on/off load current switching. (Triac switch included demo purposes only.) addition, pulse width modulation (PWM) output microcontroller filtered used variable reference comparator current sense circuitry. serial EEPROM available store watt-hour count displayed time power outage. addition, RS-232 serial port available sending receiving serial data. Firmware these functions been implemented (See Design Modifications). Linear power supply electronics provide general device power, voltage reference battery backup.
FIGURE
PICREF-3 WATT-HOUR METER (WHM) BLOCK DIAGRAHigh Voltage Electronics Small Signal Analog/Digital Sense Electronics Current Sense Circuitry Phase Sense Voltage Sense Circuitry
8-Digit Display
264V
Input
Current Sense Trans. Power Triac Gate
Load
Output
Resist. Voltage Divider
Filter Triac Control Pushbuttons Linear Power Supply Electronics Digital Analog Power, Battery Backup, Voltage References Serial EEPROM RS-232 Serial Port Voltage References
Microchip Technology's
PIC16C924
Microcontroller
264V
1997 Microchip Technology Inc.
Preliminary
DS30452A-page
PICREF-3
PIC16C924 source code written Firmware algorithms accomplish voltage current measurements, voltage current waveform phase shift measurements, real-time timekeeping, calculation display power energy consumption. addition, there code display measurements LCD. Watt-Hour Meter (WHM) reference design five modes operation, determined PIC16C924 firmware: Reset, Entry, Measurement, Sleep, Hibernate. More information each mode presented Firmware Overview.
Hardware Overview
This section describes PICREF-3 hardware functions system. Hardware detail (schematics) found Appendix
Microcontroller
PIC16C924 (Figure allows real-time interleaving sampling voltage current waveforms, power energy calculations. Also, PIC16C924 drives display (LCD) controls triac current sense input (for true current measurements).
FIGURE
PIC16C924 PINOUT
RA3/AN3/VREF RA2/AN2 RA1/AN1 RA0/AN0 MCLR/VPP COM0 RD7/SEG31/COM1 RD6/SEG30/COM2 LEGEND: Input Output Input/Output Digital Input/LCD Output Output
PLCC
RA4/T0CKI RA5/AN4/SS RB0/INT RC3/SCK/SCL RC4/SDI/SDA RC5/SDO VLCD2 VLCD3 AVDD OSC1/CLKIN OSC2/CLKOUT RC0/T1OSO/T1CKI RD5/SEG29/COM3 RG6/SEG26 RG5/SEG25 RG4/SEG24 RG3/SEG23 RG2/SEG22 RG1/SEG21 RG0/SEG20 RG7/SEG28 RF7/SEG19 RF6/SEG18 RF5/SEG17 RF4/SEG16 RF3/SEG15 RF2/SEG14 RF1/SEG13 RF0/SEG12
PIC16C924
2728 2930 3132
RC1/T1OSI RC2/CCP1 VLCD1 VLCDADJ RD0/SEG00 RD1/SEG01 RD2/SEG02 RD3/SEG03 RD4/SEG04 RE7/SEG27 RE0/SEG05 RE1/SEG06 RE2/SEG07 RE3/SEG08 RE4/SEG09 RE5/SEG10 RE6/SEG11
DS30452A-page
Preliminary
1997 Microchip Technology Inc.
PICREF-3
High Voltage Electronics
voltage (90V 264V) applied input load connected output (Figure current flow from input output through load. current continues through triac switch current sense transformer back input. current also flows through resistive voltage divider output. current sense transformer resistive voltage divider provide low-voltage analog waveforms which replicate large scale voltage current waveforms their respective sensor inputs.
FIGURE
HIGH-VOLTAGE ELECTRONICS DETAIL
264V
Input Unbalanced Input Current Signal Power Triac Gate
Triac Control
Current Sense Transformer
Load
Output
Resistive Voltage Divider
Balanced Input Voltage Signal
1997 Microchip Technology Inc.
Preliminary
DS30452A-page
PICREF-3
Small Signal Analog/Digital Sense Electronics Voltage
balanced input voltage signal from resistive divider amplified instrumentation amplifier (Figure This amplifier accomplishes signal amplification rejection common mode noise. signal amplifier output swings above below negative reference potential. amplifier output connected converter input PIC16C924. unbalanced input voltage signal tapped balanced input voltage signal connected comparator input. This comparator used compare input signal analog ground reference. comparator output goes high when input signal exceeds ground reference. output comparator provides digital voltage sense information connected line PIC16C924.
FIGURE
SMALL SIGNAL ANALOG/DIGITAL VOLTAGE SENSE ELECTRONICS DETAIL
Unbalanced Input Voltage Signal Comparator Digital Voltage Sense
Reference Balanced Input Voltage Signal Instrumentation Amplifier Analog Voltage Sense
Negative Reference
Small Signal Analog/Digital Sense Electronics Current
unbalanced input current signal from sense transformer amplified instrumentation amplifier (Figure This amplifier accomplishes signal amplification rejection common mode noise. signal amplifier output swings above below ground reference potential. amplifier output connected analog converter input PIC16C924. unbalanced input current signal also connected comparator input. This comparator used compare input signal variable positive reference (PWM reference). comparator output goes high when input signal exceeds reference. output comparator provides digital current sense information connected line PIC16C924.
FIGURE
SMALL SIGNAL ANALOG DIGITAL CURRENT SENSE ELECTRONICS DETAIL
Comparator
Digital Current Sense
Reference
Unbalanced Input Current Signal
Instrumentation Amplifier
Analog Current Sense
Reference
DS30452A-page
Preliminary
1997 Microchip Technology Inc.
PICREF-3
Microcontroller
PIC16C924 "mixed-signal" microcontroller, microcontroller capable analog digital input/output (Figure This capability used PIC16C924 control functions PICREF-3. Input Balanced/Unbalanced Sense line provides microcontroller with information whether input neutral line grounded ungrounded support worldwide power main functionality WHM.
Input
on-board converters PIC16C924 allow input analog, well digital, voltage current sense signals from Small Signal Analog/Digital Sense Electronics (Figure Depending user pushbutton input (Firmware Overview), these signals used display (LCD) calculation display. Pushbutton input digital. analog reference provided converters microcontroller. analog reference also available better resolution. Interrupt input provided into microcontroller RB0/INT. digital voltage sense line, digital current sense line, serial communication input lines each differentiated, identical circuits, wire-or'd together input RB0/INT. differentiated digital voltage sense signal used wake microprocessor from Sleep Hibernate modes.
Output
PIC16C924 feature direct drive makes display simple. information displayed determined user pushbutton input (Firmware Overview). Through filter, PIC16C924 vary analog reference voltage current sense comparator (Small Signal Analog/Digital Sense Electronics) true current measurements (Firmware Overview). microcontroller controls triac through triac control circuitry. triac (High Voltage Electronics) turned on/off pressing START/STOP pushbutton. This will turn on/off current flowing load. (Triac switch included demo purposes only.)
Input/Output
Serial EEPROM provided store data event power loss. addition, RS-232 serial port provided communication with computer. Firmware these functions been implemented (See Design Modifications).
FIGURE
MICROCONTROLLER DETAIL
8-Digit
Filter
SEG00 SEG26, COM0 COM2
RA0/AN0
Analog Voltage Sense Digital Voltage Sense Analog Current Sense Digital Current Sense
Triac Control Circuit
RA1/AN1 PIC16C924 Microcontroller
Pushbuttons
RB7, MCLR
RB0/INT
interrupt
d/dt
Serial EEPROM Reference Analog Reference
SDI, AVDD
RS-232 Serial Port
Input Balanced/Unbalanced Sense
1997 Microchip Technology Inc.
Preliminary
DS30452A-page
PICREF-3
Push Buttons
PICREF-3 pushbuttons functions listed Table more information pushbutton functions, Firmware Overview.
Firmware Overview
PIC16C924 firmware controls Watt-Hour Meter operational modes calculates power forms display. There five modes operation PICREF-3: Reset Entry Measurement Sleep Hibernation
TABLE PUSHBUTTONS
Pushbutton Name Start/Stop Cancel*; Enter; Hiber CLR*; MCLR Function Turn on/off current flow load. Cancel: Quit saving; Increment Enter: Enter info; Hiber: Enter hibernate mode Clr: Clear; Decrement Master Clear Reset
8-digit used display information each mode (Figure Each digit seven segments. Pushbuttons used control display output parameters. There Watt-Hour Meter Demo Unit available demonstrate firmware. description demo unit, Appendix
This feature implemented.
Linear Power Supply Electronics
linear power supply provides signals listed below. digital analog Battery backup (4.5V 5.5V) provides power microcontroller during power outages analog reference provides analog reference PIC16C924 on-board converters analog reference provides analog reference PIC16C924 on-board converters higher-resolution measurements signals less than peak amplitude.
FIGURE
Digit
PUSHBUTTONS
Digit
START STOP
ENTER
CANCEL HYBER
Pushbuttons
MCLR
DS30452A-page
Preliminary
1997 Microchip Technology Inc.
PICREF-3
Reset Mode
Reset mode occurs immediately after power-on reset microcontroller. Power-on reset occurs when microcontroller MCLR lowered ground potential then raised VDD. Reset will occur when: first time that battery connected circuit with input power; first time power connected circuit when there battery, time that PICREF-3 MCLR button pressed released. Digit represents tens minutes. pushbutton increase pushbutton decrease this value. Press Enter pushbutton select value. Once value selected, digit will display "0."
Digit represents single minutes. pushbutton increase pushbutton decrease this value. Press Enter pushbutton select value.
Reset mode, firmware version number shown digits Firmware Version Number
After digit value selected, selected time shown LCD. Start/Stop pushbutton enabled during Reset mode.
Note:
Entry Mode
Entry Mode occurs after Reset mode. entry mode, time must set. Also, cumulative Watt-Hours cleared (Not implemented this version document). time 24-hr clock, following procedure (maximum value 24:00 before rolling over 00.00): display will show digit colons separating hours/minutes/seconds. Digit represents tens hours. pushbutton increase pushbutton decrease this value. Pressing releasing will increase decrease value one. Pressing holding will begin scrolling increase decrease value. Release pushbutton stop scroll. Press Enter pushbutton select value. Once value selected, digit will display "0."
Digit represents single hours. pushbutton increase pushbutton decrease this value. Press Enter pushbutton select value. Once value selected, digit will display
1997 Microchip Technology Inc.
Preliminary
DS30452A-page
PICREF-3
Measurement Mode
Measurement mode occurs immediately after Entry mode. When unit connected line power, load disconnected from line power through power triac TR1. start measuring power (from Reset Mode), press release START/STOP (When START/STOP released, Triac receives gate trigger pulses). triac enabled Load connected line voltage. second, voltage, current phase shift measurements made power factor, true power watt-hour calculations carried out. Power Factor "PF" Range: 0.199 0.999
True Power Watts Range: 2640W
Measurement Mode Display
there input, goes into Sleep mode.
Watt-Hrs "Hr" maximum watt-hours displayed will 999999, will then roll over 000000.
Measurement Mode Display Load
there current flow load, display shows Frequency, Voltage Current OFF" message) Time. Each value displayed seconds before next parameter displayed.
stop power measurement, press release START/STOP button.
Measurement Mode Display Current Flowing
there current flow load, display shows Frequency, Voltage, Current, Power Factor, True Power Watt-Hrs. Each value displayed seconds before next parameter displayed. Because 7-segment digit display used, letters used measurement parameter units. Therefore, following abbreviations have been selected each parameter: Frequency letter displayed. Range: Frequency resolved either
Voltage Range: 264V. Also 000.00 voltages less than load/no current.
Current "A". numbers displayed when current waveform shape unknown. Range:
DS30452A-page
Preliminary
1997 Microchip Technology Inc.
PICREF-3
Sleep Mode
Sleep Mode entered when microcontroller executes SLEEP assembly instruction, located within interrupt service routine sleep.c file. interrupt service routine called when voltage dropout detected. battery provides power microcontroller Sleep Mode (Remove black heat shrink tubing from positive battery terminal battery backup operation.). processor clock stopped this time. Disconnecting line voltage anytime will cause unit into Sleep mode. this mode, displayed digit LCD. unit will maintain time minutes. line voltage applied then, after minutes, unit will automatically enter Hibernate mode conserve battery life. (Time keeping function Sleep mode implemented this version document.) unit will automatically exit Sleep mode when line power applied return Measurement mode.
Voltage Current Measurements
This section discusses voltage current measurements that made PIC16C924 firmware during Measurement mode.
Voltage
peak detect, responding algorithm used. sinusoidal voltage waveform sampled determine peak value. Absolute calibration point data stored sinusoidal load voltages (see Voltage Sensor Calibration list calibration point values). each calibration point, whole fractional part load voltage corresponding voltage conversion stored. 8-bit integer representing hundreds tens millivolts (ex; 690mV) stored. This stored value rate change mV/sample between calibration point next higher calibration point. increase voltage resulting from difference between conversion result conversion result calibration point calculated multiplying rate mV/sample number samples. resulting difference voltage added voltage stored calibration point form final load voltage result.
Hibernate Mode
Hibernate mode defined complete shutdown power consuming microcontroller peripherals prior entering Sleep mode. real-time clock updated during this mode. When power drop-out detected, display will flash "S." Hiber pushbutton pressed while message showing, microprocessor will into hibernate mode display will first show then blank. Hiber pushbutton pressed while display shows "S," processor will into Sleep mode display will blank. After minutes Sleep mode, Hibernate mode entered automatically (Not implemented this version document). Applying line voltage will cause unit exit Hibernate mode enter Entry mode.
1997 Microchip Technology Inc.
Preliminary
DS30452A-page
PICREF-3
Current True Measurements
True measurements highly dependent waveform shape. watt-hour meter first determines waveform shape then calculates true values. True current calculations based recognition waveform shape constant factors these waveform shapes technically sound, cost approach true current measurements. PICREF-3 provides algorithms fundamental shapes linear resistive, linear inductive narrow sinewave pulses. More complex shapes will likely combinations these fundamental shapes recognized through more complex algorithms based fundamental shape algorithm. (Complex combinations waveform shapes implemented.) peak current waveform amplitude sample first determined order ensure that comparator reference values exceed waveform's peak amplitude. Current waveforms then digitally scanned determine waveform type. digital scan accomplished varying reference voltage digital current sense comparator. reference voltage varied filtering modulated pulse width from microcontroller's output. comparator reference voltage increased from ground maximum signal level varying step sizes), digital pulses synchronized with analog waveform zero crossings created. count when pulses high kept create digital current scan. count numbers applied firmware algorithms which determine current waveform shape. Once wave shape determined, appropriate true algorithms applied.
Current Linear Loads
Linear loads inductive resistive. These loads create variable phase shift between applied sinusoidal voltage waveform phase-shifted sinusoidal current waveform. Figure shows voltage current waveforms linear inductive load, drill press. Figure shows these waveforms linear pulses. peak detect, waveform shape, responding algorithm used. current waveform sampled determine peak value. Absolute calibration point data stored sinusoidal load currents (see Current Sensor Calibration list calibration point values). each calibration point, whole fractional part current corresponding current conversion stored. 8-bit integer representing hundreds tens milliamps (ex; 100mA) stored. rate change mA/sample between calibration point next higher calibration point also stored. integer numbers used store current rate change mA/bit. integer number represents tens single milliamps (ex; 40mA) other integer number represents tenths hundredths milliamps (ex: 0.80 mA). increase current resulting from difference between conversion result conversion result calibration point calculated multiplying rate mA/sample number samples. resulting difference current added current value stored calibration point form final current result.
DS30452A-page
Preliminary
1997 Microchip Technology Inc.
PICREF-3
FIGURE LINEAR LOAD WAVEFORMS
voltage current
FIGURE
LINEAR LOAD WAVEFORMS WITH LOGIC PULSES
digital voltage sense pulse
voltage
digital current sense pulse current
1997 Microchip Technology Inc.
Preliminary
DS30452A-page
PICREF-3
Current Non-linear Loads
Non-linear loads created active circuitry, such switching power supplies. Figure shows peak non-linear current pulses peak voltage computer monitor load. Figure shows logic pulses, developed watt-hour meter, well waveforms Figure These pulses synchronized current voltage zero crossings.
FIGURE
SINUSOIDAL VOLTAGE NON-LINEAR PULSED CURRENT WAVEFORMS
voltage
current
FIGURE
SINUSOIDAL VOLTAGE NON-LINEAR CURRENT WAVEFORMS WITH LOGIC PULSES
digital voltage sense pulse
voltage current digital current sense pulse
DS30452A-page
Preliminary
1997 Microchip Technology Inc.
PICREF-3
value sine pulse current waveform varies square root inverse waveform's period. value current sine pulse, integrated over half cycle exciting voltage waveform, predicted Equation average phase shift count then applied algorithm which counts number degree phase shift increments. total number increments used index into cosine function offset look-up table. This table contains integer offset which, when added long integer base number, yields long integer cosine result phase angles between 78.5°, which corresponds power factors ranging from 0.999 0.199. Note: power factor load less than 0.199, meter will display 0.199.
EQUATION CURRENT VALUE
0.707 Where: Current sine pulse width Voltage waveform half cycle
rolling two-sample average used obtain average power factor reading. power factor calculations from consecutive second measurement intervals averaged determine power factor displayed. firmware counter 16-bit integer variable which phase shift count resolution better than 0.1° degrees frequencies between microcontroller oscillator operating MHz.
0.707 Peak-to-RMS ratio sine wave where sine wave half cycle equals integration period. firmware measures current sine pulse width voltage waveform half cycle time. These numbers then applied Equation determine value sine pulse. factors resulting from Equation pulse widths ranging from stored arrays respectively. number tenths counted used index number access array elements. arrays hold integer offset numbers which added integer base number form calculation result Equation factor used calculate true current follows. constant representing amount current sample value 0.001 multiplied number samples found peak current. result then multiplied factor found given pulse width which results true current narrow pulse waveform.
True Power
True power Watts found multiplying apparent power power factor.
Energy Calculations
This section discusses energy calculations that made PIC16C924 firmware from power calculations time measurements.
Watt-Hours
true power calculation made once second. Energy joules obtained converting true power joules/sec joules. watt-hour obtained each accumulation 3600 joules.
Power Calculations
This section discusses power calculations that made PIC16C924 firmware from voltage current measurements. definitions these power forms, Design Background.
Apparent Power
voltage current, whole fractional numbers multiplied obtain apparent power.
Power Factor
Power factor determined using phase shift count look-up table. Phase shift measured current waveforms that phase shifted from voltage waveforms 78.5°. firmware counter counts between rising edges voltage current comparator outputs. total phase shift count from consecutive cycles second measurement interval divided obtain average phase shift count.
1997 Microchip Technology Inc.
Preliminary
DS30452A-page
PICREF-3
Firmware Detail
PIC16C924 firmware written consists following modules: main.c Main program. Contains INCLUDE statements files listed below, plus modified header file, 16C924.h. Modified header file. Redefined some letters standard header make code more readable display instructions. Cosine table used calculating power factor. microprocessor sleep. control. display codes numbers through Contains messages. Real-time clock. Interrupt service routines. Determine power state (on/off). Triac control (triac on/off). Determine current digital scan. Sample current, voltage neutral line. Current measurements. Determine phase difference between current voltage waveforms. Determine current waveform shape. Determine line voltage frequency. Power energy calculations. voltage current calculation. Look-up tables absolute voltage calibration points rates between calibration points. Look-up tables absolute current calibration points rates between calibration points. Determine neutral line state (grounded/ungrounded). finds pulsed current values arrays holding integer offsets narrow pulse factors
FIGURE
RESET MODE START {main.c}
16C924.h
microcontroller pins turn TMR1
pf_table.c sleep.c lcd_808.c lcd_code.c message.c time.c int_serv.c pwrstate.c triac.c pwm.c sample.c i_meas.c phase.c
Initialize {lcd_808.c}
Display firmware version
Entry Mode FIGURE ENTRY MODE Reset Mode
time {time.c}
Measurement Mode
shape.c freq.c power.c v_meas.c v_table.c
i_table.c
ac_sense.c inl_meas.c rms_nlp.c
Program flow diagrams found following pages. Firmware listing information found Appendix
DS30452A-page
Preliminary
1997 Microchip Technology Inc.
PICREF-3
FIGURE MEASUREMENT MODE MEASUREMENT LOOP Entry Mode
Clear Timer1 second counter)
Sense neutral line state (grounded/ungrounded) {ac_sense.c}
Clear variables
Determine current waveform shape {shape.c}
current sense comparator {pwm.c}
linear resistive
linear inductive
nonlinear
Sleep Mode
Measure line frequency {freq.c}
Calculate {power.c}
Measure voltage {v_meas.c}
Calculate true power {power.c}
Current flow load?
Calculate watt-hours {power.c}
Wait till TMR1 sec.
Increment seconds counter update realtime clock {time.c}
Loop time second
1997 Microchip Technology Inc.
Preliminary
DS30452A-page
PICREF-3
FIGURE MEASUREMENT MODE MEASUREMENT LOOP, CON'T
linear resistive Measure peak current sample {i_meas.c}
linear inductive Measure phase shift (voltage/current) {phase.c, power.c}
nonlinear Measure peak current sample (pulse width) {i_meas.c}
Calculate True Current {v_meas.c}
Calculate power factor {pf_table.c}
Calculate True Current {i_meas.c, inl_meas.c, rms_nlp.c}
Measure phase shift (voltage/current) {phase.c, power.c}
Measure peak current sample {i_meas.c}
Measure phase shift (voltage/current) {phase.c, power.c}
Calculate power factor {pf_table.c}
Calculate True Current {v_meas.c}
Calculate power factor {pf_table.c}
DS30452A-page
Preliminary
1997 Microchip Technology Inc.
PICREF-3
FIGURE MEASUREMENT MODE DISPLAY LOOP
Entry Mode
Display line frequency
Display voltage
Determine current waveform shape current Display current
current
Display power factor Display OFF" Display true power
Display watt-hours
Display time
Time each block seconds
1997 Microchip Technology Inc.
Preliminary
DS30452A-page
PICREF-3
FIGURE SLEEP HIBERNATE MODES line voltage disconnected
Write last calculated watt-hr value last cumulative watt-hr value Serial EEPROM {mem_rw.c}
Display
Hiber pushbutton pressed?
Measurement Mode
Power reconnected? minutes passed?
Display
Hibernate Mode
Blank display
Reset Mode
Power reconnected?
Dashed blocks implemented this version document.
DS30452A-page
Preliminary
1997 Microchip Technology Inc.
PICREF-3
Test Results
Results PICREF-3 tests listed below. 115V/230V, motor 50Hz, 220V Start-up current: 4.9A Steady state current: 1.7A
Comparison Test
PICREF-3 Watt-Hour Meter measurements were compared measurements commercial watt-hour meter, Yokogawa WT2010 Digital Power Meter, which basic measurement accuracy 0.03%. results this comparison several PICREF-3 demo units TBD. individual demo unit test results, attached page(s).
Non-Linear Load Tests
Mitsubishi Color Display Monitor (Model FW6405ATK) tested with PICREF-3
Calibration
This section describes calibration procedure equipment used. signal source used Hewlett Packard 6814B Power Source/Analyzer. measurement reference used Yokogawa WT2010 Digital Power Meter.
Linear Resistive Load Tests
Halogen lamps different wattage were tested with PICREF-3 120V: Wattages from 1100W 240V: 1000W, 2000W
Voltage Sensor Calibration
applied load connected triac turned Resistors adjusted provide conversion result ungrounded neutral line grounded neutral line. ungrounded neutral line, there voltage sensor curve, grounded neutral line, there another. These voltage sensor curves, developed R26, viewed piecewise linear curves with absolute calibration points 90V, 100V, 110V, 120V, 130V, 150V, 200V, 210V, 220V, 230V, 240V 260V Calibration voltage sensor frequency independent. volt/sample rate used calculate voltage between absolute voltage calibration points.
Linear Inductive Load Tests
Fractional horsepower motors used with PICREF-3 listed below. Start-up steady state currents also shown. 115V, 2-speed motor 60Hz, 120V High speed start-up current: 11.5A High speed steady state current: 8.8A speed start-up current: 10.9A speed steady state current: 4.2A 115V, 2-speed motor 60Hz, 120V High speed start-up current: 17.3A High speed steady state current: 7.0A speed start-up current: 12.5A speed steady state current: 4.25A 230V, 2-speed motor 60Hz, 220V High speed start-up current: 8.8A High speed steady state current: 2.1A speed start-up current: 2.7A speed steady state current: 1.4A 230V, 2-speed motor 50Hz, 220V High speed start-up current: 7.5A High speed steady state current: speed start-up current: 5.6A speed steady state current: 1.75A 115V/230V, motor 60Hz, 120V Start-up current: Steady state current: 2.9A 115V/230V, motor 50Hz, 120V Start-up current: 7.5A Steady state current: 115V/230V, motor 60Hz, 220V Start-up current: 3.7A Steady state current: 1.2A
Current Sensor Calibration
resistive load connected voltage applied Resistors adjusted provide conversion result 0xFB load current 10A. Separate current sensor curves stored 50Hz 60Hz. current sensor curves, developed viewed piecewise linear curves with absolute calibration points 0.5A, 0.7A, 1.0A, 2.5A, 3.5A, 5.00A 10.00A. calibration current sensor independent state neutral line. current sensor calibration frequency dependent. mA/bit rate used calculate currents between absolute current calibration points.
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Phase Sensor Calibration
phase shift between digital voltage sense waveform digital current sense waveform adjusted with phase shift capacitor U5-5. Inductive loads with power factors between connected phase shift capacitor adjusted cause WT2010 power meter phase circuit phase difference match frequency 50Hz. circuit phase difference monitored with digital storage oscilloscope. Inductive loads with power factors spanning specified measurement range connected Absolute phase calibration points obtained close 2.5°, 25°, 50°, 70°, 78°. phase degree/sample rate used calculate phase shifts between absolute phase calibration points. phase sensor calibration frequency dependent. Four piecewise linear phase curves stored following conditions: neutral line grounded neutral line grounded neutral line grounded neutral line grounded
FIGURE
COMPONENTS POWER
Apparent Power 1152 Reactive Power VARs 921.6 53.13° True Power 691.2 three components apparent power, true power reactive power. Apparent Power This value that would found voltmeter ammeter were used measure circuit voltage current then these measured values were multiplied together. 1152
True Power This pure resistive component measured watts.
calibration point power factor 0.999 obtained each condition.
Power Theory
example implement watt-hour meter using microcontrollers been described previous sections. However, customer wishes change part this design, then understanding design developed was, i.e., understanding power theory, essential.
Reactive Power This pure reactive component measured VARs.
VARs
true power, watts, obtained multiplying apparent power cosine angle between apparent power true power. cosine angle between apparent power true power known power factor. angle between apparent power true power equal angular displacement between voltage current waveforms.
Components Power
Residential loads primarily inductive resistive. These loads represented series circuit.
FIGURE
SERIES CIRCUIT
FIGURE
TRUE POWER DEFINITION
53.13°
(53.13) Series Circuit components power delivered generator series load represented vector diagram. True Power =Apparent Power Power Factor 1152 691.2 Solid state watt-hour meters measure display energy based time accumulation true power default also provide selection alternate energy measurements VARh VAh.
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PICREF-3
Design Modifications
This reference design guidance only, anticipated that customers will modify parts With this mind, this section suggests modifications that customer wish make design. Full Cycle Current Measurements: hardware method full cycle current measurements involves additional current sensor channel. This channel would consist instrumentation amplifier with current sensor input connections reversed with respect instrumentation amplifier output amplifier then degrees out-of-phase with switching circuit/device would needed switch input between U14. 200A Current: This design modified accommodate 200A residential loads doing following: remove triac from circuit, higher-rated (200A) current sense transformer. Serial EEPROM Power Outage Data Storage Serial EEPROM provided store data event power loss. Additional firmware must written accomplish this function. Disconnecting line voltage time will cause unit into Sleep mode. this time, microcontroller should write last calculated watt-hour value last cumulative watt-hour value Serial EEPROM memory. When power restored, this data should read back into microcontroller. more information interfacing serial EEPROM PICmicro, AN567 Interfacing 24LCXXB Serial EEPROMs PIC16C54. RS-232 Communications Port RS-232 serial port provided communication with computer. Additional firmware must written accomplish this function. more information software serial port, AN593-Serial Port Routines Without Using Timer0. Five Meters PICREF-3 thought meters one. This design used guideline designs other meters, namely: Volt Meter Current Meter Power Factor Meter True Power Watt Meter Time Integrating Watt-Hour Meter
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NOTES:
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APPENDIX SYSTEM SPECIFICATIONS
Parameter Input Frequency Maximum Load Current Current Range Input Voltage Voltage Current Lagging Power Factor Leading Power Factor Power Measurement Accuracy Inductive Loads Capacitive Loads Linear resistive loads; power factor 1.000; crest factor voltage current waveforms 1.414. Current below 0.5A displayed Voltage below displayed Condition Value 0.5A 264V reading reading 0.199 1.000 1.000 1.0% average reading plus 0.2% full scale Option 1.0% reading with current automatic gain control. 1.0% average reading plus 0.2% full scale 240V 0.54W 120V 0.43W 100V Sleep Mode Hibernate Mode Based current Hibernate mode
Linear inductive loads; crest factor voltage current waveforms 1.414. Maximum Power Consumption
Maximum Battery Current Nominal Battery Current Minimum Battery Life
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PICREF-3
APPENDIX SCHEMATICS
Watt-hour meter schematics shown following pages. These schematics obtained electronically Microchip site (Visio® format).
Analog/Digital Sense Electronics. Also included filter used, with PIC16C924 PWM, produce variable reference current sense comparator true current measurements (Microcontroller I/O).
Phase Sense: Includes Voltage Sense Current Sense circuitry. Power Triac: From High Voltage Electronics. (Triac switch included demo purposes only.) Triac Control: Triac control circuitry from Microcontroller I/O. Control: Includes 8-digit LCD, PIC16C924 microcontroller pushbuttons from Microcontroller I/O. Remote Communication: Includes serial (RS-232) communications interface port from Microcontroller I/O. Battery Backup: Includes Serial EEPROM from Microcontroller Battery Backup from Linear Power Supply Electronics. Interrupt: From Microcontroller I/O.
Functional Overview
functional layout PICREF-3 shown Figure B-1. board functions relate overall functions follows. Input/Output: Input/Output from High Voltage Electronics. Power Supply: From Linear Power Supply Electronics. Voltage Sense: Includes Resistive Voltage Divider from High Voltage Electronics voltage sense amplifier comparator from Small Signal Analog/Digital Sense Electronics. Current Sense: Includes Current Sense Transformer from High Voltage Electronics current sense amplifier comparator from Small Signal
FIGURE B-1:
FUNCTIONAL BLOCK DIAGRA
Output
8-Digit Control (Clock Input) Pushbuttons Phase Sense Timing (8MHz clock, TIMER1 32KHz)
Power Supply
Input/ Output
Voltage Sense
PIC16C924 Microcontroller
Current Sense
Remote Communications
Interrupt
Input
Power Triac (TR1)
Optically Isolated Triac Control
Battery Backup
Visio registered trademark Visio Corporation.
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Input/Output
B.4.1 ANALOG CURRENT SENSE voltage applied power line connector load connected outlet Alternating current flows from current signal from current sense transformer amplified amplifier accepts balanced input minimum common mode rejection ratio (CMRR) signal amplifier output U2-6 swings above below (ground) reference potential. output U2-6 connected anode Schottky diode cathode connected analog converter input PIC16C924. analog current sense signal developed across cathode B.4.2 DIGITAL CURRENT SENSE
Voltage Sense
resistive ladder (R2A, R2B, R35, R36A R36B) used voltage sensor. differential voltage develops R3,R35 that 1000:1 divide-down ratio. B.3.1 ANALOG VOLTAGE SENSE
voltage signal from resistive divider R3/R35 amplified amplifier accepts balanced input minimum common mode rejection ratio (CMRR) signal amplifier output U1-6 swings above below negative volt reference potential. output U1-6 connected anode Schottky diode D10. cathode connected analog converter input PIC16C924. analog voltage sense signal developed across cathode diode D10. B.3.2 DIGITAL VOLTAGE SENSE
Comparator dual comparator integrated circuit. Half used compare sensed analog current signal (U5-5) variable positive reference (U5-6). digital current sense output (U5-7) goes high when sensed current signal exceeds reference. comparator output U5-7 connected anode Schottky diode D12. cathode connected digital input PIC16C924. digital current sense signal developed across cathode D12. B.4.3 REFERENCE FILTER
Comparator dual comparator integrated circuit. Half compares analog ground reference U5-2 single-ended voltage sensor signal developed across U5-3. output U5-1 switches logic high level when voltage sensor signal exceeds analog ground reference. comparator output U5-1 applied anode Schottky diode D11. cathode connected digital input line PIC16C924. digital voltage sense signal developed across cathode D11. B.3.3 INPUT BALANCED/UNBALANCED SENSE LINE
output microcontroller frequency 7.81 kHz. waveform duty cycle 10-bit resolution resulting single step pulse width pulses filtered R29, 470, C28, 2.2µF. These components form pass filter with break frequency pass filtered signal applied current sense comparator reference U5-6.
Phase Sense
Input Balanced/Unbalanced Sense Line used determine whether input neutral line grounded ungrounded. microcontroller input firmware analog input voltage across resistors R36A sampled. voltage positive, neutral line from input grounded. voltage zero, neutral line grounded. After microcontroller determines neutral line state, input firmware digital.
Phase Sense combination Voltage Sense Current Sense circuitry, plus phase shift circuitry U5-5. phase shift between digital voltage sense waveform digital current sense waveform adjusted with phase shift low-pass filter U5-5. phase shift circuitry adjusted calibration purposes.
Control
heart Control electronics PIC16C924 microcontroller, microcontroller receives analog digital current voltage sense signals. Depending user pushbutton input S4), these signals used display calculation display.
Current Sense
Current flows through triac current sense transformer voltage developed across burden resistor that proportional current flow.
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eight-digit, seven segment digit, display. Additional segments make periods colons necessary decimal time display. total segments. Three commons used multiplexing drive scheme. part, VIM-808-DP, manufactured V.L. Electronics Inc. B.6.1 CONTRAST ADJUSTMENT tors, C17. purpose these resistors rapidly discharge when Timer turned prior entering Hiber mode.
Remote Communications
charge pump formed resistors R24, capacitors C10. charge pump consists constant current source, internal which sources current into R24. voltage developed across applied VLCD1. charge pump boosts VLCD1 into VLCD2 VLCD1 VLCD3 VLCD1 varying R24, contrast adjusted. B.6.2 PUSH BUTTONS MCLR
serial interface circuit provided RS-232 communication between computer PICREF-3. Serial port connection provided Firmware this function been implemented (See Design Modifications).
Triac Triac Control Circuit
Triac switch included demo purposes only. triac control circuit comprised (MOC3042), triac output opto-coupler with zero crossing detect circuitry. Resistor limits forward current 10mA U13's infrared when control line pulled low. Resistor limits current gate power triac (High Voltage Electronics) when fires. Microcontroller toggled response pressing START/STOP button. Action taken change ON/OFF state triac after first zero crossing released START/STOP button.
processor reset signal manually applied U4-2, master clear (MCLR) input. reset signal originates node resistor (10k) capacitor (0.1 µF). connected digital line causing charge R17/C14 node tied pushbutton momentary pushbutton which normally open position. Depressing then releasing causes voltage level U4-2 drop ground then return low-going logic pulse U4-2 resets processor's program counter beginning firmware program. B.6.3 CLOCK INPUT
Battery Backup
battery backup section consists batteries, series with diodes D9B, Serial EEPROM. B.9.1 BATTERIES
clock input frequency external three-terminal resonator designated XTAL1. resonator, manufactured Panasonic (EF0-EC8004A4), nominal center frequency 8.00 built-in phase shift capacitors. resonator element connects OSC1 OSC2 pins U4-24 U4-25. PIC16C924 microcontroller internal inverter connected between OSC1 OSC2 pins. This internal inverter combined with resonator establish clock input frequency. B.6.4 TIMER1
event line voltage dropout, microcontroller powered series battery combination, which provides voltages range 4.5V 5.5V cathode D9B. batteries lithium cell batteries, CR2032, manufactured Panasonic. batteries have rating. Diodes D9B, 1N4150, series with cathode connected cathodes wire-or'd configuration. B.9.2 SERIAL EEPRO
32kHz crystal, Panasonic EF0-EC8004A4 designated XTAL2, connected between U4's Capacitors C17, both connected U4-26 U4-27. These components combine with inverter internal microcontroller between pins form oscillator. This oscillator clocks Timer 16-bit counter. Timer used measure second time intervals. resistor connected across each capaci-
Serial EEPROM available provide non-volatile storage parameters during line voltage dropouts. Firmware this function been implemented (See Design Modifications). Firmware should function described below. microcontroller should provide power Serial EEPROM setting line output writing logic line. last calculated watt-hour value should added last cumulative watt-hour value previously written Serial EEPROM. resulting should written
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Serial EEPROM. microcontroller should then write logic line reduce battery current drain. Serial EEPROM, 24AA16/P, manufactured Microchip Technology. Serial EEPROM 16-Kbit electrically erasable PROM that operates down 1.8V. Resistor pull-up resistor open drain terminal Serial EEPROM. Resistor provides isolation between line Serial EEPROM. provided line microcontroller. Battery operation requires have reverse current specification. These diodes switching diodes which have reverse leakage current maximum reverse peak voltage. U11, LM4040AIZ-5.0, precision reference diode with 0.1% accuracy. receives bias current from R40. reference voltage buffered U12, LM358A. output (U12-7) applied anode D14, 1N4150. cathode tied back input terminal U4-21, analog input reference line PIC16C924 microcontroller. Diode blocks current flow from U4-21 during battery backup operation. Resistors R41, provide optional reference buffer amplifier U12. analog reference divided down R41/R33 node. ladder reference applied U12-3. output U12-1 applied U4-9. PIC16C924 microcontroller select U4-9 analog reference input. this design, zero wire resistor. values affect battery current Sleep Hibernate modes. Battery currents this document based value R33.
B.10
Power Supply
power supply provides following power forms: digital analog reference analog analog analog reference
Input applied step-down transformer MagneTek P30-200. output full wave rectified bridge rectifier BR1, General Instruments W005G-ND. full wave rectified waveform from applied capacitors which charge positive negative supply rails. Zener diodes 1N4746, provide shunt path current from capacitor current flow through reduce positive supply rail voltage less than 26V, which maximum input voltage regulator U10. Japan Radio NJM78LO8A-ND, Japan Radio NJM79LO8A-ND, provide volt regulated output voltages. U10, LM2932AZ-5.0, drop-out 5.0V regulator manufactured National Semiconductor. Diode series with diode increases virtual ground point regulator schottky diode drop. Diode provides virtual ground point regulator which diode drop above ground potential. regulated output adds diode drop terminal. Diode 1N4150, D15, 1N4150, diode 1N5817, provide wired-or scheme switching either digital from output 4.5V 5.5V from batteries Diode D13, 1N4150, limits voltage undershoot output regulator when input voltage drops out. Clamping output ground potential prevents regulator from sensing negative output voltage entering output shutdown mode when input voltage returns.
B.11
Interrupt
Interrupt input provided into microcontroller RB0/INT. digital voltage sense line, digital current sense line serial communication input lines each differentiated, identical circuits, wire-or'd together input RB0/INT, U4-13 (Figure B-2). differentiated digital voltage sense signal used wake microprocessor from Sleep Hibernate modes. digital voltage sense signal differentiated circuit consisting C11, digital current sense signal differentiated circuit consisting C12, serial communication input signal differentiated circuit consisting C15, cathodes wire-or'd together connected U4-13, RB0/INT interrupt.
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FIGURE B-2: INTERRUPT DIFFERENTIATOR BLOCK DIAGRA
Voltage Sense
analog voltage sense signal digital voltage sense signal
Filter Current Sense
analog current sense signal digital current sense signal
Remote Communications Interrupt Circuitry
PIC16C924 Microcontroller
RB0/INT
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PICREF-3
FIGURE B-3: INPUT/OUTPUT, TRIAC TRIAC CONTROL CIRCUITRY, VOLTAGE/CURRENT SENSE
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FIGURE B-4: MICROCONTROLLER, SERIAL INTERFACE CIRCUIT, SERIAL EEPRO
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FIGURE B-5: MICROCONTROLLER
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FIGURE B-6: POWER SUPPLY
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FIGURE B-7: POWER SUPPLY BATTERY BACKUP
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FIGURE B-8: OPTION CURRENT MEASUREMENT AUTOMATIC GAIN CONTROL
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APPENDIX FIRMWARE LISTING
PIC16C924 firmware source code written compiled using MPLAB-C. Source code, future updates, obtained electronically Microchip site.
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APPENDIX LAYOUT DRAWING
silk screen drawing unit shown Figure D-1. dimensions listed are, with respect orientation this page; (horizontal dimension vertical dimension). Figure unit generic silk screen as-built schematics should consulted accurate information concerning components each unit. As-built schematics provided with each unit shipped, calibration alter components used. This drawing obtained electronically Microchip site
FIGURE D-1:
WATT-HOUR METER SILK SCREEN
Watt-Hour Meter Reference
1997 2297
Design Based PIC16C924 PICREF-3
Made DM003003
120/240 AUTO SWITCH
VOLTAGE SENSE
START STOP LOAD
ENTER CONTROL
INPUT/OUTPUT
C22D11
OUTPUT
120/240V
POWER SUPPLY
INPUT
CANCEL HYBER LED1
XTAL1 XTAL2
MCLR
C10A
Current Sense
TRIAC CONTROL
POWER SUPPLY
Current Sense
LED2
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Preliminary
REMOTE COMMUNICATION
BATTERY BACKUP
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APPENDIX BILL MATERIALS (BOM)
This appendix lists Bill Materials (BOM) PCB. schematics found Appendix
TABLE E-1:
Item
WATT-HOUR METER (PICREF-3) BODescription Component Part Manufacturer, Contact AD620AN, Analog Devices, (617) 329-4700 24AA16/P, Microchip Technology, (602) 786-7200 PIC16C924 08I/L, Microchip Technology, (602) 786-7200 PLCC 68P-T-2, McKenzie, (510) 651-2700 LM393N, National Semiconductor, (408) 712-5800 (800) 272-9959 (USA Only) VIM-808-DP-RC-S-HV, Electronics, Inc., (213) 738-8700 NJM78L08A, JRC, NJM79L08A, JRC, LM2931AZ-5.0, National Semiconductor, (408) 712-5800 (800) 272-9959 (USA Only) LM4040AIZ-5.0, National Semiconductor, (408) 712-5800 (800) 272-9959 (USA Only) LM358A, National Semiconductor, (408) 712-5800 (800) 272-9959 (USA Only) MOC3042, Isocom, (214) 423-5521 20E0MF1/4W-B Yageo, 886-2-917-7555 5043ED1M000F, Philips, (914) 246-2811 (800) 234-7381 (USA only) 5043ED1K000F, Philips, (914) 246-2811 (800) 234-7381 (USA only) RN60C 68.1K Dale, (402) 563-6506 Generic Distrib Distributor Newark
Instrumentation Amplifier Serial EEPRO
Microcontroller (8MHz)
PLCC Socket Dual Comparator
U4-Socket
978-2220, Allied LM393N-ND, DigiKey
LCD, Multiplexed Display
10995-ND, DigiKey
3-Terminal Regulator, 8.0V, TO-92 Terminal Regulator, 8.0V, TO-92 Positive 5.0V Regulator, TO-92
NJM78L08A-ND, DigiKey NJM79L08A-ND, DigiKey LM2931AZ-5.0-ND, DigiKey
Reference Diode, 0.1%,
LM4040AIZ-5.0-ND, DigiKey
Dual Operational Amplifier
LM358AN-ND, DigiKey
Triac Output Optoisolator Metal Film Resistor, Metal Film Resistor,
MOC3042IS-ND, DigiKey 20.0XBK, Digikey 50F8317, Newark
Metal Film Resistor,
50F8302, Newark
Select Resistor, Alignment Metal Film Resistor,
58F006R 68.1K, Newark
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TABLE E-1:
Item
WATT-HOUR METER (PICREF-3) (CON'T)
Description Component R10, R13, Part Manufacturer, Contact Yageo, 886-2-917-7555 Yageo, 886-2-917-7555 Yageo, 886-2-917-7555 Yageo, 886-2-917-7555 Yageo, 886-2-917-7555 5063JD1K000F, Philips, (914) 246-2811 (800) 234-7381 (USA only) Yageo, 886-2-917-7555 Yageo, 886-2-917-7555 Yageo, 886-2-917-7555 Yageo, 886-2-917-7555 3352E-1-254, Bourns, (909) 781-5500 RN60C 63.4k Dale, (402) 563-6506 Generic Generic Generic 3K83MF-1/4W-B Yageo, 886-2-917-7555 Generic Yageo, 886-2-917-7555 Generic Yageo, 886-2-917-7555 CTS, (219) 293-7511 AGC-12, Cooper, (414) 549-5000 102074, Little Fuse, (847) 824-0400 2N3904, Motorola, (602) 244-6900 2N4403, Motorola, (602) 244-6900 100QBK-ND, DigiKey 770-83-R 470-ND, DigiKey 94F2182, Newark 27F1086, Newark 2N3904-ND, DigiKey 2N4403-ND, DigiKey 5.1QBK-ND, DigiKey 3.83KXBK, Digikey Distrib Distributor 360QBK-ND, DigiKey 100KQBK-ND, DigiKey 2.2KQBK-ND, DigiKey 470QBK-ND, DigiKey 4.7KQBK-ND, DigiKey 50F8359, Newark
Carbon Film Resistor, 360, 1/4W Carbon Resistor, Carbon Resistor, 1/4W Carbon Resistor, 470, 1/4W Carbon Resistor, 10%, 1/4W Metal Film Resistor,
Carbon Resistor,
R17, F1-Clips
10KQBK-ND, DigiKey
Carbon Resistor, 10%, 1/4W Carbon Resistor, 10%, 1/4W Carbon Resistor, 10%, 1/4W Trimmer Potentiometer, Metal Film Resistor, 63.4 Carbon Resistor, Metal Film Resistor, 1/4W Metal Film Resistor, 1/4W Metal Film Resistor, 3.83 Select Resistor, Alignment Carbon Resistor, 1/4W Metal Film Resistor, 1/4W Carbon Resistor, 1/4W 8-pin resistor network, Fast Acting Fuse, 0.25 1.25, Fuse Clips Transistor, TO-92 Transistor, TO-92
910QBK-ND, DigiKey 180QBK-ND, DigiKey 12KQBK-ND, DigiKey 3352E-1-254, DigiKey 58F006R 63.4k, Newark
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TABLE E-1:
Item
WATT-HOUR METER (PICREF-3) (CON'T)
Description Component Part Manufacturer, Contact V420LA10, Harris, (407)724-7000 (800) HARRIS (USA Only) 1N4746A, Motorola, (602) 244-6900 1N4150, Diodes Inc., (805) 446-4800 1N5817, Diodes Inc., (805) 446-4800 EF0-EC8004A4, Panasonic, (714) 373-7366 C-001R 32.768K-A, Epson, (310) 787-6300 PF30-200, MagneTek, (219) 297-3111 CSE187-L, MagneTek, (219) 297-3111 W005G-ND, General Instrument, (516) 847-3000 515D477M035CG6A, Sprague, (603) 224-1961 1C10Z5U103M050B, Sprague, (603) 224-1961 199D107X0010EE2, Sprague, (603) 224-1961 1C10Z5U104M050B, Sprague, (603) 224-1961 ECU-S1J474MEB, Panasonic, (714) 373-7366 125LD10, Sprague, (603) 224-1961 1C10C0G330J050B, Sprague, (603) 224-1961 199D225X0025AA1, Sprague, (603) 224-1961 CR2032, Panasonic, (714) 373-7366 1026, Keystone, (718) 956-8900 (800) 379-3943 (USA only) GSP1.3101.1, Schurter, (707) 778-6311 (800) 848-2600 (USA only) 4300.0251, Schurter, (707) 778-6311 (800) 848-2600 (USA only) Distrib Distributor V420LA10, Newark
MOV, 420V
Zener diodes, 18V, High Speed Switching Diode, 0.5W, D0-35 Schottky Barrier Rectifier, DO-41 Ceramic Resonator/w built caps Crystal Resonator Mount Transformer Current Sense Transformer Bridge Rectifier
XTAL1 XTAL2
1N4746A-ND, DigiKey Sterling
Newark PX800-ND, DigiKey SE3201-ND, DigiKey DigiKey 10515-ND, DigiKey W005G-ND, DigiKey
Aluminum Electrolytic Capacitor, Ceramic Capacitor, 0.01
26,11,12 C9A, C10A C16, C27, 2-Holder
50F072, Newark 81F2060, Newark
Tantalum Capacitor, Ceramic Capacitor,
17F2029, Newark 81F2061, Newark
Monolithic Ceramic Capacitor, 0.47 Ceramic Capacitor, 0.001 Ceramic Capacitor, Tantalum Capacitor, Lithium Battery, Terminal Coin Type 20mm Coin Cell Lithium Battery Holder Power Line Connector Input Power Line Connector Output
P4919-ND, DigiKey 46F5228, Newark 95F7168, Newark 17F2041, Newark P189-ND, DigiKey 1026K-ND, DigiKey
509-1269, Allied
509-1271, Allied
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TABLE E-1:
Item
WATT-HOUR METER (PICREF-3) (CON'T)
Description Component TR1-Heat Sink TP1, Part Manufacturer, Contact DEKL-09SAT-F2, Cinch, (708) 981-6000 Q4010L5, Teccor, (214) 580-1515 531002B02500, AAVID, (603) 528-3400 EVQ-PAD04M, Panasonic, (714) 373-7366 131-5031-00, Tektronix, (503) 627-5000 (800) 426-2200 (USA only) Distrib Distributor 95F4128, Newark Q4010L5-ND, DigiKey HS190-ND, DigiKey P8007S, DigiKey
Right Angle, DB9, Connector Triac, amps TO-220 Heat Sink, Extruded Pins Momentary Switch Circuit Board Test Points
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APPENDIX WATT-HOUR METER DEMO UNIT
This Demo Unit designed showcase PIC16C924 microcontroller watt-hour meter application.
Demo Unit Assembly
DANGER
Electrocution Hazard Disassemble Unit
Watt-Hour Meter demo unit view shown figure below.
Demo Unit Specifications
specifications this demo stated Appendix
FIGURE F-1:
DEMO ASSEMBLY
Output Protective Covering Electronics Power Electronics
8-Digit
Push Buttons
PIC16C924 Serial EEPRO
Input
Serial Port
Current Sense Transformer
Battery Backup
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Demo Unit
DANGER
Electrocution Hazard Disassemble Unit
damage. Display desired power energy information display pressing push buttons (See Firmware Overview).
Recommended Loads
following loads recommended: Linear Resistive Loads (Halogen lights):
Caution
Load current MAXIMUM.
Follow these steps PICREF-3 Demo Unit: Plug receptacle power cord into Demo Unit Input". Plug pronged power cord into wall socket. Input will accept voltages 264V range. Note: grounded power cord MUST used proper operation meter.
180W 250W 500W 1000W 2000W
Linear Inductive Loads (Fractional horsepower motors): 115V; 1/2, 1/3, Non-linear Loads: Computer monitor
Plug load into Demo Unit Output" socket. Steady state load currents range measured. Surge currents have been applied unit without
FIGURE F-2:
DEMO ASSEMBLY SIDE
PIC16C924
Power Electronics
Output
Input
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1997 Microchip Technology Inc.
Preliminary
DS30452A-page
WORLDWIDE SALES SERVICE
AMERICAS
Corporate Office
Microchip Technology Inc. 2355 West Chandler Blvd. Chandler, 85224-6199 Tel: 602-786-7200 Fax: 602-786-7277 Technical Support: 786-7627 Web: http://www.microchip.com
ASIA/PACIFIC
Hong Kong
Microchip Asia Pacific 3801B, Tower Metroplaza Hing Fong Road Kwai Fong, N.T., Hong Kong Tel: 852-2-401-1200 Fax: 852-2-401-3431
EUROPE
United Kingdom
Arizona Microchip Technology Ltd. Eskdale Road Winnersh Triangle Wokingham Berkshire, England RG41 Tel: 44-1189-21-5858 Fax: 44-1189-21-5835
Atlanta
Microchip Technology Inc. Sugar Mill Road, Suite 200B Atlanta, 30350 Tel: 770-640-0034 Fax: 770-640-0307
India
Microchip Technology Inc. India Liaison Office Legacy, Convent Road Bangalore 025, India Tel: 91-80-229-0061 Fax: 91-80-229-0062
France
Arizona Microchip Technology SARL Zone Industrielle Bonde Buisson Fraises 91300 Massy, France Tel: 33-1-69-53-63-20 Fax: 33-1-69-30-90-79
Boston
Microchip Technology Inc. Mount Royal Avenue Marlborough, 01752 Tel: 508-480-9990 Fax: 508-480-8575
Korea
Microchip Technology Korea 168-1, Youngbo Bldg. Floor Samsung-Dong, Kangnam-Ku Seoul, Korea Tel: 82-2-554-7200 Fax: 82-2-558-5934
Germany
Arizona Microchip Technology GmbH Gustav-Heinemann-Ring D-81739 Germany Tel: 49-89-627-144 Fax: 49-89-627-144-44
Chicago
Microchip Technology Inc. Pierce Road, Suite Itasca, 60143 Tel: 630-285-0071 Fax: 630-285-0075
Italy
Arizona Microchip Technology Centro Direzionale Colleoni Palazzo Taurus Colleoni 20041 Agrate Brianza Milan, Italy Tel: 39-39-6899939 Fax: 39-39-6899883
Shanghai
Microchip Technology Shanghai Golden Bridge Bldg. 2077 Yan'an Road West, Hong Qiao District Shanghai, 200335 Tel: 86-21-6275-5700 Fax: 21-6275-5060
Dallas
Microchip Technology Inc. 14651 Dallas Parkway, Suite Dallas, 75240-8809 Tel: 972-991-7177 Fax: 972-991-8588
Singapore
Microchip Technology Taiwan Singapore Branch Middle Road #07-02 Prime Centre Singapore 188980 Tel: 65-334-8870 Fax: 65-334-8850
Dayton
Microchip Technology Inc. Prestige Place, Suite Miamisburg, 45342 Tel: 937-291-1654 Fax: 937-291-9175
JAPAN
Microchip Technology Intl. Inc. Benex 3-18-20, Shinyokohama Kohoku-Ku, Yokohama-shi Kanagawa Japan Tel: 81-45-471- 6166 Fax: 81-45-471-6122 10/31/97
Angeles
Microchip Technology Inc. 18201 Karman, Suite 1090 Irvine, 92612 Tel: 714-263-1888 Fax: 714-263-1338
Taiwan, R.O.C
Microchip Technology Taiwan 10F-1C Tung North Road Taipei, Taiwan, Tel: 2-717-7175 Fax: 886-2-545-0139
York
Microchip Technology Inc. Motor Parkway, Suite Hauppauge, 11788 Tel: 516-273-5305 Fax: 516-273-5335
Jose
Microchip Technology Inc. 2107 North First Street, Suite Jose, 95131 Tel: 408-436-7950 Fax: 408-436-7955
Toronto
Microchip Technology Inc. 5925 Airport Road, Suite Mississauga, Ontario 1W1, Canada Tel: 905-405-6279 Fax: 905-405-6253
rights reserved. 1997, Microchip Technology Incorporated, USA. 12/97
Printed recycled paper.
Information contained this publication regarding device applications like intended suggestion only superseded updates. representation warranty given liability assumed Microchip Technology Incorporated with respect accuracy such information, infringement patents other intellectual property rights arising from such otherwise. Microchip's products critical components life support systems authorized except with express written approval Microchip. licenses conveyed, implicitly otherwise, under intellectual property rights. Microchip logo name registered trademarks Microchip Technology Inc. U.S.A. other countries. rights reserved. other trademarks mentioned herein property their respective companies.
DS30452A-page
1997 Microchip Technology Inc.

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