4 devices...1 rotary switch

Discussion in 'The Projects Forum' started by Aamer04, Aug 19, 2010.

  1. Aamer04

    Thread Starter New Member

    Aug 19, 2010
    Hi, i'm new to this site and love it so far!

    I'm trying to use a Rotary switch that has 3-sections, 2 poles each, in order to select between 4 devices (each device has a tx, rx, gnd, and power). For each device selected I need to have 2 outputs simultaneously.

    I'm a little confused on how this rotary switch works, I've never used one before. Can anyone explain how this rotary switch works or how I should wire the switch? Here is a link to the one i'm using:

    I'd appreciate any advice, thanks!
  2. retched

    AAC Fanatic!

    Dec 5, 2009
    It is simply a switch.

    When you turn it, the connections cgange between one (or more) contact to another.

    There are options you need to worry about.

    Rotary switches come in different flavors (as you have seen) but they also come in different switching types.

    They have break before make, which means the previous contact is completely separated from the pad before contacting the next pad.

    This will keep the second device from receiving any unwanted information or power from the first (or third).

    There are also make before break.

    Which lets two pads touch during switching.

    Old TV sets often had these. If you turned the knob between 2 channels, you would see both of them on the screen. This is because the knob did not break the contacts for the first channel before making contact with the second channel.

    You can probably see how this could be a problem.

    If you were using a rotary switch as a selector for a multi-voltage AC power supply and setting
    1 was 1.5v and
    setting 2 was 3v
    setting 3 was 5v
    setting 4 was 9v
    setting 5 was 12v
    then it continued back to the 1st setting (1.5v)

    When changing voltages, you would connect 12v and 1.5v together for a short time while switching between setting 5 and setting 1 IF the rotary switch was NOT 'break before make'
  3. marshallf3

    Well-Known Member

    Jul 26, 2010
    Can you make a simple sketch of the controlled components involved along with indicating what could be held as common (such as the power &/or ground) inputs to them?

    It just sounds too simple considering some of the other stuff that comes up in here on a regular basis.