A visitor counter is a machine that counts the of number people who visited a place. Visitor counters are usually installed at the entrance and exit points of commercial buildings such as shopping malls, theme parks, museums, Airports, schools, departmental shops and other business etc. The registered counts on the machine are used for business […]
Indicator Circuits
Shunt Resistor Calculator for Ammeters
Ok so here we have one simple calculator which can help us to calculate the shunt resistor value that we need to connect across a normal ammeter when we want to use that ammeter to measure high current, more than its actual range. So normally, ammeter can measure only small current, like 1 amp or […]
IC 741 Low Battery Indicator Circuit
The proposed circuit was requested by one of the avid readers of my blog. It is a low battery warning indicator circuit using op amp IC 741 and can be used for monitoring a particular low battery voltage threshold. Circuit Operation The circuit may be understood with the following points: The entire configuration is wired […]
Simple LED Music Level Indicator Circuit
An LED music level indicator is a circuit that will respond to the connected music levels and illuminate a chain of LEDs sequentially in a push-pull switching manner, in accordance with the varying music intensity. Since the illumination level of the switching LED chain appear to extend forward and backward proportionately in response to the […]
5 Useful Power Failure Indicator Circuits Explained
In this post I have explained 5 useful power supply failure indicator circuits which can be used to get an instant indication regarding an input power failure situation. This post includes the following 5 types power failure indicator circuits: Main Function The main function of the proposed power failure indicator circuits is to alert or […]
Simple Water Level Indicator Circuits (with Images)
A water level indicator is an electronic circuit which indicates the various levels of water inside a tank. This happens when rising or dropping water levels come in contact with the respective water sensors arranged step wise inside the water tank at different depths. In this post I have explained 2 interesting ways to make […]





