วงจรดิจิตอลโวลท์มิเตอร์และแอมป์มิเตอร์
Adjustments Voltmeter: Short circuit in the input, pins 10 and 11 [IC1] and we regulate the RV1, until we take clue in the Display, zero in all the digits. We rectify and connect in the input a external voltage roughly 900mV. With the RV2, we regulate so that we take the clue 900mV in the Display. At the same time, we check this voltage with a external multimeter, of good quality and precision. Amperemeter: Short circuit in the input, pins 10 and 11 [IC3] and we regulate the RV4, until we take clue in the Display, zero in all the digits. We rectify and we connect in + IN point, provided that we place in series with the positive pole, of battery, a resistor 10R/10W and in the IN, a new battery 9V. We regulate the RV3 so that we take clue in the Display 0.90A. We check simultaneously the correctness of measurement with a external digital ambermeter. A point that it should we are careful, the capacitors C4 and C9, it should they are very good quality. Also the various in the placement of resistors R4 and R7. of connection two circuits, for measurement voltage and current, appear in the Fig.3. The power supply that is public for two circuits appears in the Fig.4. If exist suitable constant supply in the appliance in which will be placed permanently the circuits, then can remove the T1 and bridge GR1 and is connected this voltage, in point A. The IC5 good is placed in heatsink. Feature V in maximum: 100V [99.9V] A in maximum: 10A [9.99A] Max. measurement Voltage Error: 100mV Max. measurement Ampere Error: 100mA |
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