TREE

This entire circuit of beeper cum visual indicator is build and fabricated around two timer ICs and is configured in an astable multivibrator mode. The frequency generated by IC 1 is controlled by capacitor C 1 . The output from pin 3 of IC 1 is given to input pin 4 of IC 2 and base of voltage amplifier transistor T 1 through resistor R 4 . Flashing light is connected to collector of switching transistor T 2 and grounded through resistor R 7 . The output of IC 2 is obtained from pin 3 and is given to base of power amplifier transistor T 3 used to drive 8-ohm speaker connected to the collector. NOTE: LED can be replaced with 3V to 12V DC bulb after eliminating resistor R 7 . Beeper visual indicator Circuit Diagram   PARTS LIST Resistors (all ¼-watt, ± 5% Carbon) R 1, R7 = 330 Ω R 2 = 6.8 KΩ R 3 = 5.6 KΩ R 4 = 47 KΩ R 5 , R 6 = 22 KΩ Capacitors C 1 = 100 µF/10V electrolytic C 2 , C 4 = 0.1 µF ceramic disc C 3 = 0.01 µF ceramic disc C 5 = 1000 µF/25V electrolytic Se...

This is a simple timed beeper circuit diagram of beeper using 555 timer. This circuit can be employed to energize lights, horn, or other signaling device at any desired interval when the mercury switch is triggered. Since the current handling capability of mercury switch is not so high, an SCR is used to handle current drawn by the 555 timer circuit . Chose the SCR  current rating of 500mA at minimum to safely drive the 555 IC and the relay. The relay is not needed when the current drawn by alarm is less than 200mA, in this case the alarm can be installed to directly replace the relay coil.  Here is the schematic diagram of the circuit. 555-IC Timed Beeper Circuit Diagram