Principle circuit of simple LED voltmeter

Probe current voltage pin 420*4450 head diameter 5.0 over current current and voltage pin

TP-IP4220CZ6 5V 0.35PF breakdown voltage 6V SOT

Shunuo varistor / ESD varistor / product complete / Sunlord first-class agent

SMD LED

As shown in the figure, the number of light-emitting diodes is used to display the voltage level of the voltage. The transient response is fast, and the internal resistance of the voltmeter is high, and the display is intuitive. When the measured voltage U is higher, the number of light-emitting diodes from the LED1-LED4 is increased. Adjust the resistance of the potentiometer W to adjust the starting voltage value of LED1 lighting.