Tone Generator-Ding-Dong Bell

Tone Generator Circuit


Here we present a simple and low cost tone generator circuit, a ding dong bell suitable for calling bell purposes.It is made around IC 8021. It is an 8 pin IC but only four pins are shown here. 8021 has an in-built circuitry to produce ding dong sound each time its pin 3 is pulled low. The sound is stored in a 4 bit ROM. A complementary-pair, two-transistor amplifier is used to amplify the sound to a fair level of audibility. A piezoelectric tweeter or an 8-ohm, 500mW speaker  can be used at the output.

Each time when 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 produced, it has no effect whatever and the two ding-dong bell sounds will be invariably produced.S1 is the ON- OFF switch. Assemble the circuit on a good quality all purpose PCB.Don’t forget to use an IC holder for IC 8021.

Tone Generator Circuit Diagram.

Tone Generator Circuit

We have more Tone Generator circuits in our website, that may interest you: Take a look:

1. Police Siren using 555

2. Whistle to Beep Circuit

3. Touch Controlled Musical Bell

4. Musical Horn Circuit

5. Multitone Alarm Circuit

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7 thoughts on “Tone Generator-Ding-Dong Bell

  1. h Sinclair

    I can find no data on the 8021-2 chip for the tone generator ding dong.
    Who makes it?
    How do I get a data sheet?
    Where is it available?
    What sort of sounds is it capable of producing?
    Could it for instance make a sound like a commercial doorbell a la “Avon calling”


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