4 LED voltage indicator circuits ElecCircuitcom Circuit Diagram This LED DC voltage indicator circuit is a voltmeter, rather than simply a battery tester. As such it may measure voltages as low as 3V. It utilizes venerable LM741 operational amplifiers applied as comparators that drive LED indicators. Voltage thresholds are 3, 6, 9 and 12V. Above each incremental threshold an additional LED turns on. A simple electronic part such as an LED can play an important role in displaying and monitoring the condition of this AC mains voltage and warn us of a possible electrical hazard. Here, I have explained exactly how to make ac voltage indicator using leds through a construction of a little electronic circuit. I want to design a circuit that has 3 LEDs connected to it. When the voltage of the power source connected to the circuit is 3.6 volts I want only the first LED to light. 7.2 volts I want the
Description This circuit, designed on request, has proven to be useful to indicate when the voltage in a power supply line is changing from 120V to 240Vac. It can be used in different circumstances and circuits, mainly when an increase in ac or dc supply voltage needs to be detected. The beeper circuit is built around this IC so when the IC activates it will blink the LED and the buzzer will start producing a beep beep sound, giving an indication of the detection. The time period of LED and buzzer activation is set by the values of the resistor and capacitor used at the input of 555 IC.
Contact AC Voltage Detector using 2N3819 MOSFET Circuit Diagram
A voltage sensor circuit is a circuit that can sense the voltage input into it. If the voltage reaches a certain threshold, then an indicator, such as an LED, will turn on. In this circuit, we will show how to build a voltage level indicator with a single zener diode. A voltage level indicator is a circuit which can show if the voltage input into a circuit is greater than a certain threshold level. If the voltage is greater than a certain level, then an output such as an LED can light up or a buzzer can sound off.
This is four circuits of LED voltage indicator are simple and easy to builds for check voltage battery and others, use as zener,transistor,LM339 and more
