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...
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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...
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Head phone amplifier circuit

admin April 7, 2010 2 Comments
Description. Here is a simple head phone amplifier circuit that can be used to drive your head phone if your music player doesn’t have  enough power to drive your head phones.The circuit is straight forward and uses only three...
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Sound pressure meter

admin April 7, 2010 3 Comments
Description. Here is a simple circuit that can be used to check the sound levels.The sound pressure meter is vey useful in setting up home theater systems , if you need to test the sound pressure of each channels...
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Speech amplifier circuit.

admin April 7, 2010 10 Comments
Description. This circuit given here can be housed in the box containing the speaker to form a handy microphone amplifier.The device can be used by teachers,guides,lecturers etc for speaking in a crowdy or noisy environment. The circuit is designed...
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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...
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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....
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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...
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Sound shifter circuit

admin April 7, 2010 1 Comment
 Description. Here is superb sound shifter circuit that can be used to add effects to the input sound signal.The circuit is ideal for incorporating in toys and adds great fun.The circuit can be also used in mixers and recorders....
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3 Band graphic equalizer circuit.

admin April 7, 2010 14 Comments
Description. Here is a simple 3 band graphic equalizer circuit  made of a single op amp IC LF351 (IC1) and few passive components.The component values of this circuit are not very critical and can be replaced with nearest values...
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