Showing posts from April, 2011Show all
Melody generator for greeting cards
Melody generator for greeting cards
This tiny circuit comprising of a single 3 terminal IC UM66 can be built small enough to…
Water Level Indicator with alarm
Water Level Indicator with alarm
This circuit not only indicates the amount of water present in the overhead tank but als…
A simple electronic buzzer
A simple electronic buzzer
This very simple circuit just uses a couple of resistors, a capacitor and the easily ava…
Rain Alarm
Rain Alarm
This circuit gives out an alarm when its sensor is wetted by water. A 555 astable multiv…
Theft preventer alarm
Theft preventer alarm
This circuit utilising a 555 timer IC can be used as an alarm system to prevent the theft…
Power supply failure alarm
Power supply failure alarm
Most of the power supply failure indicator circuits need a separate power supply for them…
Sawtooth wave generator
Sawtooth wave generator
Sawtooth wave generators using opamp are very common. But the disadvantage is that it req…
Simple variable frequency oscillator
Simple variable frequency oscillator
This is a very simple circuit utilising a 555 timer IC to generate square wave of frequen…
