General Info

Discussion in 'The Projects Forum' started by chimera, Oct 22, 2010.

  1. chimera

    Thread Starter Member

    Oct 21, 2010
    Hello! Im a fellow electronic enthusiast and am a student in electronics engineering at Virginia Tech. Its my final year and Ive gathered enough knowledge on some basic circuitry developement. So ive gone towards the art of designing circuits my self. Ive decided to surf the internet and get some ideas by looking at some circuits and seeing how they work and how can they be modified to fit certain criterias. Well, Ive been looking at this one particular circuit and was trying to implement it. It uses a metal plate. Now ive tried googling it and nothing definitive comes up that helps me understand what this component is. If someone knows what this is, please identify it and state a substitute for it if possible. Thanks a bunch!!!
  2. bertus


    Apr 5, 2008

    Without any component values it is hard to expain the circuit.
    I think the IC is an cmos version of the 555.

  3. jpanhalt


    Jan 18, 2008
    It's just a touch switch using a 555. The two "contacts" (MP1 and MP2) can be any metal item. When they are touched, that grounds/discharges them and causes the appropriate relay action. Some versions of the switch have two contacts, one grounded and one to the appropriate pin. The user's finger acts as a short. However, other versions just rely on a discharge through the user's body. Your circuit appears to be that latter type. Here is a link and explanation:

    Last edited: Oct 22, 2010