question about doorbell mod

Discussion in 'The Projects Forum' started by madman6233, Aug 14, 2012.

  1. madman6233

    Thread Starter New Member

    Mar 4, 2011
    the ic that I picked is apt8a977bpe and 8a978 bpe I am simply wanting to build a multi use wireless footswitch for around the shop.
    I was told to put a relay in place of the speaker, but then I simply get it to pulse on and then shut off . I have been reading through the guide books thanks so much btw and believe I could use a transistor and flip flop to achieve an on when pressed then press again for off switch.
    My question is this ic has a built in oscillator If I made my footpedal trigger this function could I then use it as a momentary switch as well as latching it through functon 2.

    also are there any other things I should include now that would be useful to have it capable of later on?
  2. wayneh


    Sep 9, 2010
    That's a question?

    Consider safety above all else. Foot switches risk being splashed, crushed, tripped over etc. And you haven't said how you're using it to switch power. I assume you want relatively high current switching, for electric motors like drills, saws, etc?
  3. vk6zgo

    Active Member

    Jul 21, 2012
    If you are using a "wireless" doorbell circuit to operate pieces of equipment in your "shop",be aware that "wireless" in these devices means"radio".
    This means they are subject to interference from other uses of the radio spectrum,including,not least,other doorbells.
    If a doorbell gives a false indication,that is harmless,but if the same thing happens to a unit controlling machinery,it could be extremely dangerous.
  4. elec_mech

    Senior Member

    Nov 12, 2008
    What you're describing is a T-type flip flop. This can be made with a 7474 (5V) or CD4013 (6-15V) D-type flip flops by tying the Q Not pin to the D(ata) pin. The datasheet shows your ICs to be 5V, so if you're directly interfacing to these, then the 7474 would need to be used. As you mentioned, you'd need a transistor, MOSFET, or relay to use the output signal to turn something on. You might want to look at solid state relays.

    As others have mentioned, there are a number of safety factors to consider in this application. I can't speak to all of them, but when dealing with wireless, I prefer to use something premade. I'd suggest something like this one of our other members pointed out to me in another post:

    Be safe and good luck.
  5. madman6233

    Thread Starter New Member

    Mar 4, 2011
    I do appreciate the stresses on safety I actually have gone a bit overboard My workshop has a oversized fuse box in it then goes to one outside my house and my lathe,mill,saws,and now well as each work area has largish blade type switches when I am rewiring a motor I need to look up and see that switch open and pointing skyward first lol.
    mainly My plan is to use this for different musical applications have relays handy that can manage dremels and maybe drill but probably not my drill press, lathe,or the mill I am hopig to get/build one day.

    My specific purpose at the moment is around 24v dc 4 amp walwort (laptop) that I added lm350s or 17s too and made variable to run and tune tattoo machines after building new coils for them.
    My dream is to just have ten spots to hang the machines that can be remotely triggered one at a time using the same powersupply now I have to have three sets of cords and psu-s as well as three footpedals to show a customer three different machines or hook and unhook retune the voltage for each one such a pain.

    The other thing I would like is my wife to have a remote to turn lights outside shop on and make one inside strobe when she wants me and I haven't heard the intercom. LOL

    I had been leaning towards a flip flop for simplicity but a latching relay may still win out Though for small pedals I will have to see and of course look up t type flip flops as this is twice today that was recommended.
    Thanks again I will see about hitting my local shop some time this week to try building out both thoughts so I might understand them better.