Door bell circuit using NE555

jacky January 27, 2014 18 Comments
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 as the time period of the monostable multivibrator built around IC1....
read more

Lamp flasher circuit

admin April 7, 2010 6 Comments
Description. This simple circuit that can be used to flash incandescent lamps up to 10W power rating.The circuit is ideal for making flashing beacons on automobiles and other applications like that.The circuit is nothing but  an astable multi vibrator...
read more

Water level alarm circuit

admin January 23, 2018 131 Comments
Description. Here is a simple water level alarm circuit using 555 timer that will produce an audible alarm when the water level reaches  a preset level.The circuit can be powered of a  3V battery and is very handy to...
read more

12 V Florescent lamp driver circuit

admin April 7, 2010 8 Comments
Description. Here is a simple and effective circuit for driving florescent lamps from a 12 V supply.The circuit is nothing but consists of an oscillator, a MOSFET switch and a step-up transformer for driving the florescent lamp. The IC1...
read more

Contactless telephone ringer circuit

admin April 7, 2010 5 Comments
Description. The contact less telephone ringer circuit can produce a ring as well as a visual indication when a call comes.The main advantage is that since there is no direct contact between the phone line and the circuit there...
read more

Mobile incoming call indicator

admin January 23, 2018 203 Comments
Description. This circuit can be used to escape from the nuisance of mobile phone rings when you are at home. This circuit will give a visual indication if placed near a mobile phone even if the ringer is deactivated....
read more

Shock alarm circuit

admin April 7, 2010 20 Comments
 Description. Here is a simple shock sensitive alarm circuit that has many many applications fro home to automobiles.The main application of this circuit is to use it as an anti theft alarm in automobiles.A peizo electric sensor is used...
read more

Telephone off-hook indicator

admin April 7, 2010 2 Comments
Description. The circuit depicted here can be used as an indicator when the telephone receiver is off-hook. The circuit can be in corporated with old telephones that does not have such an indicator. The circuit uses a complementary darling...
read more

Street light circuit.

admin March 8, 2012 221 Comments
Description. The circuit diagram present here is that of a street light that automatically switches ON when the night falls and turns OFF when the sun rises. In fact you can this circuit for implementing any type of automatic...
read more

High & Low voltage cut-off with delay& alarm

jacky March 8, 2012 101 Comments
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 back. An ideal circuit for home to protect your valuable equipments...
read more