Digital Ammeter circuit using pic microcontroller

• IC7107
• LM555
• PCB (Wellpcb.com)
• LM7805
• Common anode 7 segment LED display (Quantity: 4)
• Terminal Block 2 pin (2)
• 47k
• 1k (5)
• 22k
• 10K
• 120K
• Pot 5K
• 100nF (3)
• 10uF (2)
• 100pF
• 220nF
• 47nF
• Power Supply 9v/12v
• Berg sticks (2)
• 40 pin IC base
• 8 pin IC base
• Probe or wire
• 1N4148 diode (2)

Step 2: Circuit Diagram and Working Explanation

Working of this electronic voltmeter Circuit is extremely straightforward. ADC within the IC is desegregation device or twin kind Analog to digital device. Internal ADC of this IC reads the voltage that to be measured and compare it with an indoor reference voltage and converts that into the digital equivalent. Then this digital equivalent is decoded for seven section Displays by driver circuit within ICL7107 and so showed over four seven segments diode display.

Here electrical device R1 and electrical capacitor C1 area unit won’t to set the frequency of internal clock of ICL7107. Electrical capacitor C2 filters the fluctuations in internal reference voltage and provides stable reading on seven phase displays. R5 is to blame for dominant the variations of the meter. (R5=1K for 0-20V vary and 10K for 0-200V range). RV1 could be a potentiometer which can be used for calibrating the voltage of meter or may be set the reference voltage for internal ADC.
This circuit includes four Common Anode Seven phase light-emitting diode Displays with a negative voltage indicator. This circuit ought to be operated at 5V voltage offer, that’s why we’ve got used a 7805 transformer IC to provide 5v to the circuit still as for preventing the injury of ICL7107. Negative Voltage Supply: Here we’ve got conjointly have to be compelled to offer negative power to PIN twenty six of the ICL7107, that we’ve got used 555 IC. The 555IC timer IC is designed here as ASTABLE multi-vibrator. The electrical device here may be modified but the choice ought to pursue for optimum negative voltage. If hand-picked capacitance doesn’t suit well, then we have a tendency to can’t get most negative voltage at the output. Here we’ve got used 100nF and 10uF.

Source: Digital Ammeter circuit using pic microcontroller