Jeopardy style push buttons

Discussion in 'The Projects Forum' started by hurtado_roberto, Oct 3, 2008.

  1. hurtado_roberto

    Thread Starter New Member

    Oct 3, 2008
    Does anyone know how to build a circuit like the one used on the Jeopardy game show... the light of the fasted person to push the button turns on.

    I designed a circuit with 3 DPDT mechanical relays, 3 push buttons, and 3 1A @ 24VAC incandescent bulbs. The schematic works but the mechanical relays are a bit slow. They're rated at 10A but the light bulbs only use about 1A. The problem right now is that if I press two button within less than 2/10ths of a second, both lights turn on.

    I'm thinking of using solid state relays but I'm unable to find cheap NC relays.

    Is there a solid state relay that has one NC and one NO circuit on it. It's for an old friend, a high school teacher, who wants to use it in his class.
  2. KMoffett

    AAC Fanatic!

    Dec 19, 2007
    Relays are slow! There are PhotoMosfet relays with 1 NO and 1 NC circuit for about $4, but the load current is only 100mA. Check Digikey. These could be used to switch transistors that drive the high current lamps. A simple alternative to relays is: I made one based on this SCR concept.