In Electronic field voltmeters have found an essential place, Voltmeters are of two types AC &DC and here I have demonstrated a working AC Voltmeter. It has a large range from 0V to 1000V.The output is shown on 7 segment display .I have used a PIC 16f676 microcontroller .The main part of this AC voltmeter project are ::-
1) Converting Circuit (For converting Ac to dc in range of 0-5V)
2) ADC Interfacing(10 bit Inbuilt ADC of 16F676)
3) 7 Segment Multiplexing
It has bridge rectifier which is made from diodes In4007.It convert Ac Voltage to Dc Voltage. Next is Voltage divider circuit which converts any voltage from 0 to 1000v to 0 to 5v range. It is made using two resistors and a potential meter in series. Next capacitor is used for removing ripples .the zener 5.1V is used for protection it will never give voltage to controller more than 5.1 V.
Introduction to Pic16f676:- Pic 16f676 is 8 bit microcontroller from microchip .It comes in 14 pin dip Package .It has 12 I/O pin for external device interface. The I/O pins have high current sink and source capacity so that they can drive led directly. It has analog comparator module with one analog comparator. It has on 8 bit timer and one 16 bit timer. It has wide frequency range from dc to 20 MHZ. It has also an external interrupt pin for external hardware interrupts.
PIN DIAGRAM OF 16F676