Wiring Schematic Diagram

This simple and low cost ding dong electronic doorbell circuit is Using IC 8021-2. The IC has an in-built circuitry to produce ding dong sound each time its pin 3 is pulled low. If you try to press switch S2 a second time when the first ding dong sound is still being produed, it has no effect whatever and the two ding-dong bell sounds will be invariably produced.S1 is the ON- OFF switch.

You may either use a piezo tweeter or an 8-ohm, 500mW speaker at the output. During the standby period, the IC consumes nominal current of a few microamperes only. Therefore switch S1 may be kept closed. Each time switch S2 is pressed, ding dong sound is produced twice. If you try to press switch S2 a second time when the first ding dong sound is still being produed, it has no effect whatever and the two ding-dong bell sounds will be invariably produced.