Help on Headset Interface

Discussion in 'The Projects Forum' started by FrogSwimmer, Oct 21, 2011.

  1. FrogSwimmer

    Thread Starter New Member

    Oct 21, 2011

    I am trying to interface a headset (with a PTT (Push to Talk) button attached to the headset)- to my computer.

    The headset is tricky because when the PTT is open, the speaker is ON and the mic is OFF. Then when the PTT is closed the speaker is OFF and the mic is ON along with the command to tell the computer the PTT function is also ON- thus activating the computer transmitter.

    The best I can figure out is to have a DPDT relay powered by the PTT (with a possible amp if needed). However, I want to stay away from a relay if I can and just use no moving parts. I'm still mastering my transistor circuits but I think my application should be possible.

    Thank you!
  2. elec_mech

    Senior Member

    Nov 12, 2008
    Hi FrogSwimmer,

    Welcome to AAC!

    I recommend you try connecting everything without the relay first and make sure it works - verify the wiring is correct and physically move and connect wires to simulate the action of the PPT button/relay. Once you know your wiring is correct and the system works like you want it to, you can move onto finding an appropriate switch. I'll try to look at your drawing later when more time allows.

    Alternates to a relay include an optical isolator or a logic switch such as a CD4066. Transistors or MOSFETs might work - my experience with them is limited and I wouldn't be the best one to offer advice on how to use them.
  3. FrogSwimmer

    Thread Starter New Member

    Oct 21, 2011
    Elec Mech,
    Thank you for the information. I have been working this for a while now and I have done single flow test on all of my components. I set up my original prototype used only relay to trigger the PTT on the computer, but I got feedback on the speaker when the mic was ON (being shorted out in the handset). The speaker works just fine when it is hooked up with the computer.
    I am almost 100 positive everything will work using my current version and I will build it once I get a new relay. But, I wanted to use transistors for all the positive reasons that come with them, and also avoided the relay breaking down with long-term physical contacts moving around. Ill look into the alternatives for a relay you mentioned. Thank you!