Electronic doorbell circuit

Published:2012/10/10 1:59:00 Author:muriel | Keyword: Electronic doorbell | From:SeekIC

This simple and cost-effective ding dong electronic doorbell circuit is based on IC 8021-2. The IC has an in-built circuitry to produce ding dong sound each time its pin 3 is pulled low. The sound is stored in the IC as bits, as in a ROM. The sound output from the IC can’t however drive a speaker directly, as this puts strain on the device.Therefore a complementary-pair, two-transistor amplifier is used to amplify the sound to a fair level of audiblity. You may either use a piezo tweeter or an 8-ohm, 500mW speaker at the output. This simple electronic doorbell has not been tested. 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. Doorbell electronic circuit diagram



Reprinted Url Of This Article:
http://www.seekic.com/circuit_diagram/Audio_Circuit/Electronic_doorbell_circuit.html

Print this Page | Comments | Reading(3)