A buzzer is a small sound making device that is used in alarms, toys, and indicators. This Simple Two Transistor Buzzer Circuit is very simple and easy to make. It uses only two transistors and therefore, it is good for beginners. Also, it works with low voltage and because of this it is safe to […]
12V Battery Low Voltage Alarm Circuit
Battery is very important in many electronic systems. However battery voltage drops with time, if voltage becomes too low then battery can get damaged. So low voltage indication is needed. Therefore, this 12V Battery Low Voltage Alarm Circuit helps to protect battery. It gives visual and sound alert and is simple and is with low […]
Low Voltage Alert Circuit for 9V Battery
Battery power is very important in electronic circuits. But many times a battery voltage becomes low without notice. As a result, devices stop working suddenly and therefore, a low voltage alarm is needed. This Low Voltage Alert Circuit for 9V Battery gives warning when a 9V battery goes low. It uses LM339 comparator IC and […]
Digital Code Lock Circuit using IC 4017
Security plays a very important role in todays world, therefore electronic code locks are very useful. This Digital Code Lock Circuit using IC 4017 is a simple. It uses push buttons, diodes, resistors, capacitor and IC CD 4017 . Moreover, it is low cost and easy to build and it works on 9V power supply. […]
Darkness Activated LED Circuit
This article explains about a Darkness Activated LED Circuit which is useful device that saves power. It is energy efficient circuit because light glows only in darkness. The circuit turns ON light at night and it turns OFF light in day time. It works fully automatic so, no manual switch is needed daily. It is […]
Fan Start 10 Second Delay Timer Circuit
In many homes and industries sometimes a fan does not turn ON immediately. A fan start delay timer is a circuit that delays the fan start. When power is applied the fan stays OFF and after some fixed time the fan turns ON automatically. In this circuit the delay time is about 10 seconds and […]