lever switch hook up

Discussion in 'The Projects Forum' started by pistons4550, Jul 9, 2013.

  1. pistons4550

    Thread Starter New Member

    Jul 8, 2013
    Hello Everyone

    I bought an spdt lever switch from radioshack for a project where I pretty much need the switch to be used as a counter. The problem is that the switch came in a bag with no data sheet or method of hooking it up. I searched on the manufacturers website but still had no luck. I was wondering if someone here could help explain to me the three, what appear to be, terminals. from left to right, they read N.C. (with a 2 on the other side), N.O. (with a 3 on the other side), and C. (with a 1 on the other side). The terminals are rectangles with a hole. I attached some pics for better clarification.

    Thanks in advance for any help
  2. JohnInTX


    Jun 26, 2012
    (C)ommon, (NC)Normally Closed, (NO)Normally Open. The common is connected to one of the other terminals depending on the lever's position.

    When the lever is up, C and NC are connected. Pressing the lever makes C and NO connected.

    How you hook it to a counter depends on the counter but a common hookup is to use a resistor to pull the counter input up, connect NO to it and C to ground. When the lever is pushed, the counter input will go from pulled up to grounded.

    Keep in mind that mechanical switches 'bounce' when the contacts transfer which will require some thought. Some counters have a built in debounce circuit, others require a clean signal which you'll have to provide.

    google NAND gate debounce for lots of information on debouncing as well as circuits you can use.

    Have fun.
  3. pistons4550

    Thread Starter New Member

    Jul 8, 2013
    Hmm didn't even know I would have to use a debounce, luckily I have some knowledge of it. Although I don't quite follow the hookup details you provided. Im not trying to hook it up to a counter, im trying to use the switch as a counter.
    Last edited: Jul 10, 2013