Keywords: T26 Dual do current and voltage table V122007
T26 Dual current and voltage table V12 do
T26 do single-channel current voltage V12 power meter
(As hardware PCB, a program to realize functions of two kinds of different table)
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Test range: 64.000V5A (0.02 ohm); 125mV current test is an equivalent table is displayed theoretical limit 64A
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Design ideas:
1, using the AVR microcontroller ATtiny26L make four pairs of differential AD converter VI groups;
2, utilizing the internal 1 and 20 times the automatic conversion of the differential amplifier to measure the voltage and improve accuracy;
3, each of the average of 256 samples do AD;
4, made using the correction data stored inside EEPROM.
SCM:
T26 default system frequency is 1MHz, through burning fuse bit T26 will be the system frequency to 8MHz. Use PonyProg2000 - Version 2.07a Beta May 3 2007 download http://www.lancos.com/ppwin95.html address
Is written into the EEPROM FLASH file * .hex file * .eep correction voltage is 2V, 19V, update the correction current is 1A: 1, hold the "ZERO" key is energized;
2, after the release display "2VtoV1"; 3, the input voltage of 2V in a first set of test voltage, press "ZERO" key;
4, after releasing the display "19VtoV1"; 5, the input voltage of 19V in the first set of test voltage, press "ZERO" key;
6, after releasing the display "2VtoV2"; 7, the input voltage of 2V in a second set of test voltage, press "ZERO" key;
8, after the release display "19VtoV2"; 9, 19V input voltage of the test voltage at the second set, according to "ZERO" key;
10, after releasing the display "0A"; 11, adjusting the output current exactly zero, press the "ZERO" key;
12, after releasing the display "1AtoI1"; 13, the input current is 2A in the first set of current test, press "ZERO" key;
14, after releasing the display "1AtoI2"; 15, the input current is 2A in the second set of current test, press "ZERO" key; this correction would not have considered is the accuracy of the resistance. Measuring range: Voltage 40V, current (125mV / R23 or R27) may be charged with an adjustable power supply before correction. Program: T26 do V2_1A.hex dual current correction current voltmeter. 1A, sampling 0.1 ohm resistance, corresponds to the maximum current of the current dual 1AT26 do V2_2A.hex correction current voltmeter. 2A, the sampling resistor is 0.05,0.02 Europe, respectively corresponding to the maximum current of 2A, 5A current voltage of the resistor power meter V2_1A.hex correction current is 1A, the sampling resistor is 0.1 ohm, a maximum current of 1A current voltage of the resistor power meter V2_2A.hex correction current. 2A, the sampling resistor is 0.05, 0.02 Europe, corresponding to the maximum current of 2A, 5A1.rar respectively
20,071,208 improvement
Correction function, increase the current zero. Adjustable power supply circuit there is more or less the leakage current, the leakage current can be subtracted by zeroing.
1, T26 do V3_2A.hex dual current correction current voltmeter. 2A, the sampling resistor is 0.05,0.02 Europe, respectively, corresponding to the maximum current of 2A, 5A2.rar
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2, T26 do V3_2A.hex dual current correction current voltmeter. 5A, the sampling resistor is 0.02,0.01 Europe, respectively, corresponding to the maximum current of 5A, 10A3.rar
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20,080,301
Current voltage of the resistor power meter (400V / 5A high pressure version)
Dividing resistor R25 is 320K Europe, European sampling resistor R27 to 0.02, corresponding to a maximum voltage of 400V current, respectively, 5A
The correction current is 0A, 1.9A, the correction voltage has two types of 0V, 20V 190V and the three sections, one for the 0V, 20V, and 40V (this correction will be measured at a high voltage larger deviation, use of fine proportion method Removes) 4.rar
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Current voltage of the resistor power meter (40V / 5A Edition)
Dividing resistors R25 to 30K Europe, European sampling resistor R27 to 0.02, corresponding to the maximum voltage and current of 40V, respectively, 5A
The correction current is 0A, 1.9A, the correction voltage is 0V, 2V and 19V three sections 5.rar
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Display: LCD test 6V white iron to a 5-membered 1602LCD yleee brother (without backlight)
Dual current voltmeter
Single channel current-voltage power meter
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Circuit diagram:
application:
J22 pins 2-3 in the circuit diagram may be separated, the separated end of the I test without a shunt resistor connected (rather voltmeter 125mV), the current setting terminal may be connected to the test set current. V test terminal may be separated after the test input voltage. Single doing so is more straightforward adjustable power supply, the input voltage, set current value, actual output voltage, output current. Separating a group of V, after testing I, the one-way connection
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