S76477 Sound Chip Circuits Help

Discussion in 'General Electronics Chat' started by nickorossa, Aug 31, 2010.

  1. nickorossa

    Thread Starter Active Member

    Jun 28, 2010
    54
    0
    Hi

    I'm finally looking at the details behind making use of the S76477 sound generator.

    Most of the circuits in the data sheet use a 2N3703 transistor as part of the output; however I'm unable to get them at my usual places. What would be a suitable alternative or is there simply a different part number for the transistor?

    http://docs.bgmicro.com/pdf/ics76477a.pdf

    Also what changes would be needed (if any) to use a 16ohm speaker rather than an 8ohm.

    Thanks.

    Nick.
     
  2. Jaguarjoe

    Active Member

    Apr 7, 2010
    770
    90
    A 2N3906 should work fine for you. Everybody sells them. FWIW- Futurelec sells the 3703 and the 3906.
    Looking at the circuit diagram, there is a 100 ohm resistor labelled "R loud"
    in series with the 8 ohm speaker and the driver transistor. To switch to a 16 ohm speaker you will need to make R loud 8 ohms less.
     
    nickorossa likes this.
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