This is a DIY Digital Voltmeter without using Microcontroller.
It is an educational circuit to measure DC voltage from 0 to 99V.
Supply voltage could be 11V to 30V DC.
Input impedance = 10 Mega ohm.
Parts list:
IC CD40110 (3pcs)
IC 7809
IC LM358
IC 4060 (2pcs)
Optocoupler PC817
Transistor 2N2222 (2pcs)
Crystal XTAL 4MHz
Capacitor 100nF (4pcs)
Capacitor 100uF 50V
Capacitor 100uF 16V
Capacitor 15pF (2pcs)
Capacitor 1uF 16V
Capacitor 10uF 16V
Resistor 2K (22pcs) or 1K for higher brightness !
Resistor 1K (3pcs)
Resistor 51K
Resistor 56K
Resistor 10M
Resistor 5.1M
Resistor 75 ohm
Resistor 200K
Resistor 10K
Resistor 91K
Potentiometer 3296 Multiturn 1M
IC Socket 8pin
IC Socket 16pin (5pcs)
Connector 3pins and wires
7Segment display single digit common cathode 0.56 inch / 1.9cm x 1.3cm (3pcs)
Circuit:
You can download the Gerber file from here:
https://drive.google.com/file/d/1NL-fRoz91zK2t0Bj8eGm51-SjZZqNmhl/view?usp=sharing
For more details watch this video: