One-at-a-time IC Switch

Discussion in 'The Projects Forum' started by mrg1999, Nov 4, 2009.

  1. mrg1999

    Thread Starter New Member

    Nov 3, 2009
    I'm trying to create a toy for my young nephews that will generate different sound effects with the press of different push button switches.
    My problem is if they press another push button while the first sound effects IC is still playing, both sounds will be playing simultaneously through the speaker (common speaker for all sound effect IC's).
    There are six different IC's and six different push button switches.

    I can design a nightmare circuit with relays or transistors that will only allow one switch to operate at a time but there has to be a better way.

    Optimally, if one switch is pressed the IC will play it's sound but if another switch is pressed while the first is still playing it's sound, the first IC will be turned off and the second turned on (additionally, if a third button is pressed, only that IC will receive the supply voltage and all others will be off).

    I'm hoping someone has more experience with an integrated circuit switch that would allow only one device to be active at a time. I've uploaded a block diagram.

    Thank you in advance!
  2. Wendy


    Mar 24, 2008
    I've something similar for a 1 of 4 selector using set reset flip flops, diodes, and a gate. I suspect 1 of 8 is more hassle than it's worth though, it would take 2 flip flop chips, and a hex invertor to convert a bunch of diode OR gates to AND gates (the flip flops provide the inverted inputs).
  3. Bernard

    AAC Fanatic!

    Aug 7, 2008
    What are your sound effects gens.? You could use one 555 and 6 caps. controlled by switches. If more than one sw. pressed, a single tone is produced at at a lower freq.
  4. SgtWookie


    Jul 17, 2007
    Something similar to what Bernard suggests, but only one timing cap and a bunch of switches and resistors:


    If you wanted to try to "tune" it somewhat, you could use 2k trimpots instead of 1k fixed resistors, but it really wouldn't be worth the effort. It'll sound sort of like a chainsaw.