Description. The main part of this doorbell circuit are two NE555 timer ICs.When some one presses switch S1 momentarily, the loud speaker sounds a bell tone as long…
Description. An NE555 timer IC connected as shown here can detect a missing pulse or abnormally long period between two consecutive pulses in a train of pulses. Such…
Description. Apart from the timing functions ,the two comparators of the 555 timer can be used independently for other applications.One example is a Schmitt Trigger shown here. The…
Description. NE555 is an IC which is widely used in timers and control circuits. A circuit for independent testing this IC is given here. Here the NE555 is…
Description. Commercially available voltage regulator IC’s can deliver up to 1A output current. For example 78xx series regulators are available in different voltage ratings, but in any case…
Description. The circuit presented her will transmit a audio tone in the FM band. The circuit can be used as a tracking signal transmitter or a remote control…
Description. Many fire alarm circuits are presented here,but this time a new circuit using a thermistor and a timer to do the trick. The circuit is as simple…
Description. This straight forward circuit will protect electrical appliances from over voltage as well as under voltage. The circuit also produces an alarm when the power supply comes…
Description. Here is a simple variable frequency circuit based on timer NE555. Here NE55 is wired as an astable multivibrator, whose output frequency can be varied by varying…
Description. A simple scoring game circuit that can be used for all occasions when a dice is needed.The circuit is based on a NE555 timer,a 74LS192 counter,a74LS247 decoder…
A simple Light to Frequency Converter Introduction. Here is the circuit diagram of a effective light to frequency converter circuit that can be used for variety of applications…
Dual Tone Train Horn Circuit – Description A dual tone train horn simulator circuit can be made using two NE 555 timers connected in cascade. Here instead of…
InfraRed (IR) Sensor/Detector Circuit The IR circuit described below is mainly designed for liquid level detection or proximity detection. The IR sensors used here are an IR LED…
A fridge door open alarm circuit is explained with its detailed working and circuit. The objective of this circuit is to produce an audible alarm when the fridge…
A digital stopwatch is an evergreen project, it can be done at any time no matter how our advanced our world’s technology is because nothing else can replace…