Timed Beeper

Posted on Jul 2, 2012

Beeps 7.5 seconds after a preset time Adjustable time settings: 15 s. 30 s. 1 min. 2 min. & others This circuit is intended for alerting purposes after a certain time is elapsed. It is suitable for table games requiring a fixed time to answer a question, or to move a piece etc. In this view it is a modern substitute for the old sandglass. Useful also for time control when children are brushing teeth (at least two minutes!), or in the kitchen, and so on.

Timed Beeper
Click here to download the full size of the above Circuit.

Pushing on P1 resets IC2 that start oscillating at a frequency fixed by R3 & C1. With values shown, this frequency is around 4Hz. LED D2, driven by IC1A & B, flashing at the same oscillator frequency, will signal proper circuit operation. SW1 sele

Leave Comment

characters left:

New Circuits



Popular Circuits

Hook Sensor Loop Circuit
Energy Saver Relay Coil circuit and explanation
Electronics Grasshopper using 555
how to build inexpensive frequency
games timer 4
Emitter-Coupled LC Oscillator
555 Timer LED Flasher Circuit
Electronic mousetrap power-saving circuit