CN1885221A - Remote controller for high precision DC power supply - Google Patents
Remote controller for high precision DC power supply Download PDFInfo
- Publication number
- CN1885221A CN1885221A CN 200510042861 CN200510042861A CN1885221A CN 1885221 A CN1885221 A CN 1885221A CN 200510042861 CN200510042861 CN 200510042861 CN 200510042861 A CN200510042861 A CN 200510042861A CN 1885221 A CN1885221 A CN 1885221A
- Authority
- CN
- China
- Prior art keywords
- pin
- circuit
- chip
- chip microcomputer
- output terminal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Landscapes
- Control Of Voltage And Current In General (AREA)
- Dc-Dc Converters (AREA)
- Microcomputers (AREA)
- Analogue/Digital Conversion (AREA)
Abstract
The invention relates to a power source remote controller based on eight-bit single chip, wherein said high-accuracy direct-current power source remote controller comprises: a single chip (1) whose address bus (10) is connected to the address decoder (3) and the data memory (4); the invention is characterized in that: it also comprises a decode output of address decoder (3) to be used as the chip select address of data memory (4), digit/analogue convert circuit (5), multi-path independent analogue/digit convert circuit (6), state input circuit (7) and switch output circuit (8); the eight-bit data bus (9) of single chip (1) is connected to the data memory (4), the digit/analogue convert circuit (5), the multi-path independently analogue/digit convert circuit (6), the state input circuit (7), and the switch output circuit (8); the serial port of single chip (1) is connected to the communication interface circuit (2). The invention can realize remote distribution control on the high-accuracy high-stability direct-current stable-current or stabilizing power source, to realize relative control targets, with better anti-interference ability.
Description
Technical field:
The present invention relates to a kind of developing Of Remote Control Power device based on 8 single-chip microcomputers.
Background technology:
At present, controller based on 8 single-chip microcomputers is only monitored the running status of power supply, can not regulate output current/or voltage, the remote voltage reference resolution of output is lower or long-term stability is relatively poor, electric current and magnitude of voltage retaking of a year or grade precision to direct supply output are lower, can not satisfy the needs of high precision high stability degree dc current stabilized power supply or stabilized voltage supply, as: output current or voltage long-term stability are less than 1 * 10
-4The requirement of Long-distance Control.
Summary of the invention:
The objective of the invention is to avoid the deficiencies in the prior art part and a kind of remote controller for high precision DC power supply is provided.Under the control of main control computer, realize the output current or the magnitude of voltage of high precision high stability degree dc current stabilized power supply or stabilized voltage supply are regulated control by designing high-resolution digital to analog converter, by designing the retaking of a year or grade of high-resolution analog to digital converter realization, to realize Long-distance Control and remote testing to high precision high stability degree dc current stabilized power supply or stabilized voltage supply to the output current or the magnitude of voltage of high precision high stability degree dc current stabilized power supply or stabilized voltage supply.The function of the present invention is integrated analog quantity input and the output of programmable analog amount.
Purpose of the present invention can be by realizing by the following technical solutions: a kind of remote controller for high precision DC power supply, include single-chip microcomputer (1), address bus (10) the link address code translator (3) of single-chip microcomputer (1) and data storage (4), its principal feature be also include address decoder (3) the decoding output terminal respectively as the chip select address of data storage (4), D/A converting circuit (5), multichannel independence analog to digital conversion circuit (6), quantity of state input circuit (7) and switching value output circuit (8); 8 bit data bus (9) of single-chip microcomputer (1) connect data storage (4), D/A converting circuit (5), multichannel independence analog to digital conversion circuit (6), quantity of state input circuit (7), switching value output circuit (8) respectively; The serial port of single-chip microcomputer (1) is connected with communication interface circuit (2).
Described single-chip microcomputer (1) is AT89C51, P00-P07 is connected with bus driver 74HC245 (U2) as data/address bus is multiplexing, latch 74HC573 (U4) latchs the least-significant byte address, its output terminal connects the A0-A7 of nonvolatile memory DS1225AD (U5), and the A8-A12 of DS1225AD is connected with P20-P24 in single-chip microcomputer (1) the most-significant byte address bus; Between the output terminal of the output terminal connecting bus driver 74HC245 of nonvolatile memory DS1225AD and the input end of latch 74HC573; 17 pin of single-chip microcomputer (1) are connected the input end of gate circuit 74HC08 (U3) with 29 pin, 1 pin of the output terminal pin 3 connecting bus driver 74HC245 of 74HC08; P25-P27 end in the most-significant byte address bus of single-chip microcomputer (1) connects 1,2,3 pin of code translator 74HC138; 15 pin of 74HC138 output terminal connect 20 pin of nonvolatile memory DS1225AD (U5); Pin 14 connects 5 pin and 6 pin of D-A converter AD669 (U8); Pin 10 connects 1 pin of data latches 74HC377 (U24); 1 pin and 5 pin of pin 13 connections or door chip 74HC32 (U34).
Remote controller for high precision DC power supply, 6,4,2 pin of analog-digital conversion circuit as described (6) voltage reference AD780 (U26) are connected with 3,2,27 pin of analog to digital converter AD976A (U25) respectively: 2,6 pin of operational amplifier A D711 pass through R
71Be connected with 1 pin of AD976A.6 pin of operational amplifier LM741 (U28) are connected with 3 pin of AD711.R
73, R
74, R
76Be connected in 2 pin of LM741 after the series connection.23 pin of AD976A are connected with 19 pin of latch 74HC573 (U4); 1 pin of 26 pin Sheffer stroke gate chip 74HC04 (U35) connects, and 2 pin of 74HC04 are connected with 13 pin of single-chip microcomputer (1); 24 pin connect U34A or door chip 74HC32 3 pin and with 2 pin of door chip 74HC08; 25 pin connect 3 pin of 74HC08, its 1 pin with U34B's or 6 pin of a chip 74HC32 be connected; 1 pin of U34A or door chip 74HC32 with U34B's or 5 pin of a chip 74HC32 be communicated with and connect 13 pin of 74HC138; 2 pin of U34A or door chip 74HC32 are connected with 16 pin of single-chip microcomputer (1); U34B's or door chip 74HC32's 4 pin are connected with 17 pin of single-chip microcomputer (1); The pin 22,21,20,19,18,17,16,15 of AD976A respectively with bus driver 74HC245 (U2) output pin 18,17,16,15,14,13,12, be connected.
AD conversion unit circuit (6) is that core constitutes with the analog-digital converter AD976A of high speed 16 bit resolutions, and 6,4 pin of high precision external voltage reference AD780 are for providing 3,2 pin of conversion reference connection AD976A; Input signal constitutes low-pass active filter filtering via operational amplifier, and the 2-6 pin of impact damper AD711 is for providing low-impedance simulating signal through R
71Be connected in 1 pin of analog-digital converter AD976A; OR circuit 74HC32, not circuit 74HC04, AND circuit 74HC08 constitute the control circuit that AD976A changes, digital quantity reads.In the two independent ADC passage, the one tunnel as the voltage retaking of a year or grade, and one the tunnel as the electric current retaking of a year or grade.
Described D/A conversion unit circuit (5) bus driver 74HC245 (U2) output pin 18,17,16,15,14,13,12,11 connects latch 74HC377U respectively
243,4,7,8,13,14,17,18 pin, its output pin 2,5,6,9,12,15,16,19 connects the pin 14,13,12,11,10,9,8,7 of D-A converter AD669 (U8) respectively; And bus driver 74HC245 output pin 18,17,16,15,14,13,12,11 also is connected with the pin 22,21,20,19,18,17,16,15 of D-A converter AD669 respectively, and 26 pin of D-A converter AD669 (U8) are through R
69With potentiometer W
7Center-side connect W
7Two ends be connected with the pin 15,1 of voltage reference AD688 (U23) respectively, 27 pin are through K
9, W
8Be connected 28 pin and K with 3 pin with 1 pin of AD688
9Between string R arranged
70 AD669 pin 26 is connected with pin 25 by K10, R68.
The D/A conversion of D/A conversion unit circuit (5) is that core constitutes with the D-A converter AD669 of 16 bit resolutions, data latches 74HC377 latchs the MSB data bit, under the control of single-chip microcomputer (1) write operation WR, least-significant byte LSB data bit and most-significant byte MSB data bit write the first order latch of analog-digital converter AD669 simultaneously and latch; Thereby realize the input of 16 bit digital quantity and latch; 16 bit data by the second level latch of the P16 control AD669 of the P1 port of single-chip microcomputer (1) AT89C51 write and latch, and carry out digital-to-analog conversion simultaneously and export aanalogvoltage.External standard of precision voltage AD688 provides high precision high stability degree+10V voltage reference for AD669, and potentiometer W7 regulates the zero point of analog quantity output, and W8 regulates the full scale output of analog quantity, and K10 selects the unipolarity of analog quantity, bipolarity output; Each build-out resistor is selected accurate wire-wound resistor for use.The unipolarity aanalogvoltage output area 0 of digital to analog converter~+ 10V, bipolarity aanalogvoltage output area-10V~+ 10V, output current is 10mA.
The invention has the beneficial effects as follows, realized long-distance distribution control high precision high stability degree direct current current stabilization or stabilized voltage supply.Each functional module is stable, develops different Control Software, reaches the control corresponding purpose; The control data reliable communications, the control command response is correct, has good antijamming capability; Control benchmark long-term stability height far away, its leading indicator is: 1. load capacity 10V/10mA, the 0-10V programming is adjustable; 2. long-term stability 2 * 10
-53. nonlinearity erron 2 * 10
-44. gain error 1 * 10
-55. repetitive error 5 * 10
-56. temperature coefficient 3ppm/ ℃; 7. resolution is 16.
Have following major function:
1.+and output of 5V level and the output of relay contact switch amount, configuration relay status LED light;
2. 8 road light isolation amounts input, and configuration status amount LED indication;
3. one tunnel 16 bit resolution analog quantity output, unipolarity output area 0~+ 10V, bipolarity output area-10V~+ 10V, output current 10mA;
4. 2 tunnel analog input channels independently, 16 of A/D conversion resolutions, analog quantity input range-10V~+ 10V;
5. the power supply service data stored record of 4KB capacity;
6. standard RS232 and RS485 remote communication interface are easy to realize multiple machine distributing control;
7. the function of power supply monitoring;
8. the pattern that adopts mimic channel and digital circuit to power respectively;
9. good antijamming capability.
After tested, controller DAC output Trendline is seen Fig. 5, and surveying instrument is a SOLARTRON high accuracy number voltage table, and Measuring Time is 8 hours, and the sampling time is 51.2 seconds.
Table 1. controller DAC output voltage and charged power output (electric current and voltage) long-term stability
Controller DAC output | Tested power supply | ||||
Output voltage (V) | Degree of stability | Power supply type | Output current and voltage | Degree of stability | |
1.68144 | 2.0×10 -5 | Stabilized current supply | 100A | 9.0×10 -5 | |
1.25467 | 4.2×10 -5 | Stabilized current supply | 125A | 1.2×10 -4 | |
0.62470 | 3.2×10 -5 | Stabilized | 37A | 9×10 -5 | |
4.99164 | 1.2×10 -5 | High-voltage power supply | 25KV | 6.8×10 -5 | |
9.95914 | 1.6×10 -5 | High-voltage power supply | 49.79KV | 5.2×10 -5 |
The precision that can find out output voltage and charged power output from table 1 has reached higher level.
Description of drawings:
Be described in further detail below in conjunction with the most preferred embodiment shown in the accompanying drawing:
Fig. 1 is a controller function block diagram of the present invention.
Fig. 2 is a controller control unit circuit schematic diagram of the present invention.
Fig. 3 is an analog to digital conversion circuit schematic diagram of the present invention.
Fig. 4 is a D/A converting circuit schematic diagram of the present invention.
Fig. 5 is a controller DAC output long-term stability trend line chart of the present invention.
Embodiment:
A kind of high-precision power remote controllers based on the MSC51 series monolithic adopt double-deck printed board structure, and two-layer printed board connects by 34 needle sockets, strengthen the compactedness of structure, reduce the planar dimension of controller, are fit to the 3U standard PC case and use.Each functional module data input is connected with the data bus of single chip computer AT 89C51, and AT89C51 is the core component of controller, and the Control Software of its burning realizes the control to each functional module.
See Fig. 1, remote controller for high precision DC power supply, single-chip microcomputer 1 is arranged, the address bus 10 link address code translators 3 and the data storage 4 of single-chip microcomputer 1, the decoding output terminal of address decoder 3 are respectively as the chip select address of data storage 4, D/A converting circuit 5, multichannel independence analog to digital conversion circuit 6, quantity of state input circuit 7 and switching value output circuit 8; 8 bit data bus 9 of single-chip microcomputer 1 connect data storage 4, D/A converting circuit 5, analog to digital conversion circuit 6, quantity of state input circuit 7, switching value output circuit 8 respectively; The serial port of single-chip microcomputer 1 is connected with communication interface circuit 2.
Seeing Fig. 2, is controller control unit circuit schematic diagram of the present invention.The single-chip microcomputer 1 of remote controller for high precision DC power supply is AT89C51, P00-P07 is connected with bus driver 74HC245 (U2) as data/address bus is multiplexing, latch 74HC573 (U4) latchs the least-significant byte address, its output terminal connects the A0-A7 of nonvolatile memory DS1225AD (U5), and the A8-A12 of DS1225AD (U5) is connected with P20-P24 in the single-chip microcomputer 1 most-significant byte address bus; Between the output terminal of the output terminal connecting bus driver 74HC245 of nonvolatile memory DS1225AD and the input end of latch cicuit 74HC573; 17 pin of single-chip microcomputer 1 are connected the input end of gate circuit 74HC08 (U3) with 29 pin, 1 pin of the output terminal pin 3 connecting bus driver 74HC245 of 74HC08; At the make decision data transfer direction of 74HC245 of the control of the read operation of single-chip microcomputer and instruction fetch operation.P25-P27 end in the most-significant byte address bus of single-chip microcomputer 1 connects 1,2,3 pin of code translator 74HC138, and 15 pin of 74HC138 output terminal connect 20 pin of nonvolatile memory DS1225AD (U5); Pin 14 connects 5 pin and 6 pin of D-A converter AD669 (U8); Pin 10 connects 1 pin of data latches 74HC377 (U24); 1 pin and 5 pin of pin 13 connections or door chip 74HC32 (U34).The reference address of each peripheral components is produced by the 74HC138 code translator.
The power supply of single-chip microcomputer 1 is monitored by power supply monitor MAX813L monitoring+5V power supply, if+when the 5V power supply was lower than 4.65V, MAX813L sent reset signal, forced single-chip microcomputer to reset.The I/O of quantity of state and switching value is connected with outside by standard 96 needle sockets.The power pin of high-speed cmos device all connects decoupling capacitor, reduces the high frequency interference of digital loop, the enhanced system antijamming capability.
See that Fig. 3 is an analog to digital conversion circuit schematic diagram of the present invention.Remote controller for high precision DC power supply, 6,4,2 pin of analog to digital conversion circuit 6 voltage reference AD780 (U26) are connected with 3,2,27 pin of analog to digital converter AD976A (U25) respectively; 2,6 pin of operational amplifier A D711 pass through R
71Be connected with 1 pin of AD976A.6 pin of operational amplifier LM741 (U28) are connected with 3 pin of AD711.R
73, R
74, R
75Be connected in 2 pin of LM741 after the series connection.23 pin of AD976A are connected with 19 pin of latch 74HC573 (U4); 1 pin of 26 pin Sheffer stroke gate chip 74HC04 (U35) connects, and 2 pin of 74HC04 are connected with 13 pin of single-chip microcomputer 1; 3 pin that 24 pin connect U34A or door chip 74HC32 with 2 pin of door chip 74HC08: 25 pin are connected 3 pin of 74HC08, its 1 pin with U34B's or 6 pin of a chip 74HC32 be connected; 1 pin of U34A or door chip 74HC32 with U34B's or 5 pin of a chip 74HC32 be communicated with and connect 13 pin of 74HC138; 2 pin of U34A or door chip 74HC32 are connected with 16 pin of single-chip microcomputer 1; U34B's or door chip 74HC32's 4 pin are connected with 17 pin of single-chip microcomputer 1; The pin 22,21,20,19,18,17,16,15 of AD976A respectively with bus driver 74HC245 (U2) output pin 18,17,16,15,14,13,12, be connected.
The present invention is made up of the two independent analog to digital conversion circuit, Fig. 6. and be one road analog to digital conversion circuit schematic diagram wherein.See Fig. 4 D/A converting circuit schematic diagram of the present invention.D/A conversion unit circuit (5) bus driver 74HC245 (U2) output pin 18,17,16,15,14,13,12,11 connects latch 74HC377U respectively
243,4,7,8,13,14,17,18 pin, its output pin 2,5,6,9,12,15,16,19 connects the pin 14,13,12,11,10,9,8,7 of D-A converter AD669 (U8) respectively; And bus driver 74HC245 output pin 18,17,16,15,14,13,12,11 also is connected with the pin 22,21,20,19,18,17,16,15 of D-A converter AD669 respectively, and 26 pin of D-A converter AD669 (U8) are through R
69With potentiometer W
7Center-side connect W
7Two ends be connected with the pin 15,1 of voltage reference AD688 (U23) respectively, 27 pin are through K
9, W
8Be connected 28 pin and K with 3 pin with 1 pin of AD688
9Between string R arranged
70 AD669 pin 26 is connected with pin 25 by K10, R68.
See that Fig. 5 is a controller DAC output long-term stability trend line chart of the present invention.
Claims (4)
1, a kind of remote controller for high precision DC power supply, include single-chip microcomputer (1), address bus (10) the link address code translator (3) of single-chip microcomputer (1) and data storage (4), the decoding output terminal that it is characterized in that also including address decoder (3) are respectively as the gating address of data storage (4), D/A converting circuit (5), analog to digital conversion circuit (6), quantity of state input circuit (7) and switching value output circuit (8); 8 bit data bus (9) of single-chip microcomputer (1) connect data storage (4), D/A converting circuit (5), analog to digital conversion circuit (6), quantity of state input circuit (7), switching value output circuit (8) respectively; The serial port of single-chip microcomputer (1) is connected with communication interface circuit (2).
2, remote controller for high precision DC power supply as claimed in claim 1, it is characterized in that described single-chip microcomputer (1) is AT89C51, P00-P07 is connected with bus driver 74HC245 as data/address bus is multiplexing, latch 74HC573 latchs the least-significant byte address, its output terminal connects the A0-A7 of nonvolatile memory DS1225AD, and the A8-A12 of DS1225AD is connected with P20-P24 in single-chip microcomputer (1) the most-significant byte address bus; Between the output terminal of the output terminal connecting bus driver 74HC245 of nonvolatile memory DS1225AD and the input end of latch 74HC573; 17 pin of single-chip microcomputer (1) are connected the input end of gate circuit 74HC08 with 29 pin, 1 pin of the output terminal pin 3 connecting bus driver 74HC245 of 74HC08; P25-P27 end in the most-significant byte address bus of single-chip microcomputer (1) connects 1,2,3 pin of code translator 74HC138; 15 pin of 74HC138 output terminal connect 20 pin of nonvolatile memory DS1225AD, 5 pin and 6 pin of 14 pin linking number weighted-voltage D/A converter AD669, and pin 10 connects 1 pin of data latches 74HC377,1 pin and 5 pin of pin 13 connections or door chip 74HC32.
3, require 1 described remote controller for high precision DC power supply as profit, it is characterized in that 6,4,2 pin of analog-digital conversion circuit as described (6) voltage reference AD780 are connected with 3,2,27 pin of analog to digital converter AD976A respectively; 2,6 pin of operational amplifier A D711 pass through R
71Be connected with 1 pin of AD976A; 6 pin of operational amplifier LM741 are connected with 3 pin of AD711; R
73, R
74, R
75The series connection back connects 2 pin with LM741; 23 pin of AD976A are connected with 19 pin of latch 74HC573; 1 pin of 26 pin Sheffer stroke gate chip 74HC04 connects, and 2 pin of 74HC04 are connected with 13 pin of single-chip microcomputer (1); 24 pin connect U34A or door chip 74HC32 3 pin and with 2 pin of door chip 74HC08; 25 pin connect 3 pin of 74HC08, its 1 pin with U34B's or 6 pin of a chip 74HC32 be connected; 1 pin of U34A or door chip 74HC32 with U34B's or 5 pin of a chip 74HC32 be communicated with and connect 13 pin of 74HC138; 2 pin of U34A or door chip 74HC32 are connected with 16 pin of single-chip microcomputer (1); U34B's or door chip 74HC32's 4 pin are connected with 17 pin of single-chip microcomputer (1); The pin 22,21,20,19,18,17,16,15 of AD976A respectively with bus driver 74HC245 output pin 18,17,16,15,14,13,12, be connected.
4, remote controller for high precision DC power supply as claimed in claim 1 is characterized in that described D/A conversion unit circuit (5) bus driver 74HC245 output terminal D0-D7 connects U respectively
243,4,7,8,13,14,17,18 pin of latch 74HC377, its output pin 2,5,6,9,12,15,16,19 is the pin 14,13,12,11,10,9,8,7 of linking number weighted-voltage D/A converter AD669 respectively; And bus driver 74HC245 output terminal D
0-D
7Also be connected with the pin 22,21,20,19,18,17,16,15 of digital to analog converter AD669 respectively, 26 pin of digital to analog converter AD669 are through R
69With potentiometer W
7Center-side connect W
7Two ends be connected with 3 with the pin 15 and 14,1 of voltage reference AD688 respectively, 27 pin are through K
9, W
8Be connected 28 pin and K with 3 pin with 1 pin of AD688
9Between string R arranged
70AD669 pin 26 is connected with pin 25 by K10, R68.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CNB2005100428617A CN100458635C (en) | 2005-06-24 | 2005-06-24 | Remote controller for high precision DC power supply |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CNB2005100428617A CN100458635C (en) | 2005-06-24 | 2005-06-24 | Remote controller for high precision DC power supply |
Publications (2)
Publication Number | Publication Date |
---|---|
CN1885221A true CN1885221A (en) | 2006-12-27 |
CN100458635C CN100458635C (en) | 2009-02-04 |
Family
ID=37583394
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CNB2005100428617A Active CN100458635C (en) | 2005-06-24 | 2005-06-24 | Remote controller for high precision DC power supply |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN100458635C (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN103557830A (en) * | 2013-10-30 | 2014-02-05 | 北京理工大学 | Angle measuring plate card compatible with various sensors |
CN105388805A (en) * | 2015-11-01 | 2016-03-09 | 四川泛华航空仪表电器有限公司 | SPI (Serial Peripheral Interface) bus-based measurement control system |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2357601B (en) * | 1999-12-23 | 2004-03-31 | Ibm | Remote power control |
CN2526908Y (en) * | 2001-06-14 | 2002-12-18 | 武汉大学 | Universal system board of single board computer based on PSD |
CN2676257Y (en) * | 2004-01-09 | 2005-02-02 | 朱路 | Multiway control device for power supply |
CN2807318Y (en) * | 2005-06-24 | 2006-08-16 | 中国科学院近代物理研究所 | DC power source remote control device |
-
2005
- 2005-06-24 CN CNB2005100428617A patent/CN100458635C/en active Active
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN103557830A (en) * | 2013-10-30 | 2014-02-05 | 北京理工大学 | Angle measuring plate card compatible with various sensors |
CN103557830B (en) * | 2013-10-30 | 2017-02-08 | 北京理工大学 | Angle measuring plate card compatible with various sensors |
CN105388805A (en) * | 2015-11-01 | 2016-03-09 | 四川泛华航空仪表电器有限公司 | SPI (Serial Peripheral Interface) bus-based measurement control system |
CN105388805B (en) * | 2015-11-01 | 2018-04-06 | 四川泛华航空仪表电器有限公司 | Measurement and Control System based on spi bus |
Also Published As
Publication number | Publication date |
---|---|
CN100458635C (en) | 2009-02-04 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN1021376C (en) | Adjustment circuit and method for solid-state electricity meter | |
CN209327889U (en) | 4-20mA programme control precision current source | |
CN1885221A (en) | Remote controller for high precision DC power supply | |
CN211375364U (en) | Multichannel multi-type analog sensor access circuit | |
CN2807318Y (en) | DC power source remote control device | |
CN104897385B (en) | Efp dedicated test circuit system | |
CN103746693A (en) | Calibration circuit eliminating capacitor mismatch error | |
CN2574062Y (en) | Current signal conditioning circuit | |
CN1077684C (en) | Temp measuring circuit | |
CN2570782Y (en) | Intelligent humiture self-compensation sensing transducer | |
CN107145142B (en) | Testing device and multi-online testing system | |
CN201060236Y (en) | Combination type power load accurate measurement device circuit structure | |
CN2695936Y (en) | Intelligent thermometer calibrater | |
CN109768695A (en) | Voltage and current compensation correction system and its working method based on FPGA | |
CN113972915B (en) | Gray code signal setting threshold circuit of pressurized water reactor rod position measurement system | |
CN103634009A (en) | Method for improving analog-to-digital conversion accuracy of analog quantity collection device | |
CN2601395Y (en) | Digitized weighting module | |
CN218122504U (en) | Humidity channel of high-precision automatic meteorological station signal simulator | |
CN106597078A (en) | Single-chip-microcomputer-based automatic measurement system design of wide-range voltage signal | |
CN2840226Y (en) | Fuel-oil rack position indicator | |
CN2224420Y (en) | PH/potential intelligent analysis and test instrument | |
CN2689176Y (en) | Controller of straight-reading digital count meter | |
CN221124835U (en) | High-precision electronic load calibration module | |
CN202583932U (en) | Numerical control direct current stabilized power supply | |
CN2580535Y (en) | Voltage signal modulation circuit |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
C06 | Publication | ||
PB01 | Publication | ||
C10 | Entry into substantive examination | ||
SE01 | Entry into force of request for substantive examination | ||
C14 | Grant of patent or utility model | ||
GR01 | Patent grant |