Would a SSR work or what should I use?

Discussion in 'The Projects Forum' started by Chills24, Oct 30, 2009.

  1. Chills24

    Thread Starter Member

    Nov 10, 2008
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    I have a circuit that has photo sensor that when light is on allows current and at the end of the circuit drives a motor. If I short around the sensor it will also cause it to spin the motor. I have a 5v remote source that I want to be used when a push button is pressed it causes this short around the photo sensor and allows the motor to spin. The 5v source is separate from the power source of the motor. The problem I have is what would be a suitable device to cause this short? A SSR or a mechanical relay maybe. Speed is very important so I want something with very little delay. I thought of using a transistor possibly but couldn't think of the right configuration. Also the 5v source is from batteries so it is not ideal for it to always be on. I basically want the 5v to activate something to create a short around the photo transistor.
     
  2. MikeML

    AAC Fanatic!

    Oct 2, 2009
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    Post a circuit. I cant figure out if your photo sensor is supposed to turn on the motor as well as a switch, or what?
     
  3. Chills24

    Thread Starter Member

    Nov 10, 2008
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    Thanks for replying, here's a real basic picture. So what I'm looking to do is have some sort of short that I can control using the 5v power supply. One of the problems is the Voltage around the photo transistor is 1v or less. The 5V is also a small separate power supply with very minimum current. So basically I want a small sort of 5v switch that will short out the photo transistor( from a to b) so that the circuit acts as if current is flowing through it but the signal is actually being controlled outside of the circuit itself. Please let me know if you need more explanation.
    [​IMG]
     
  4. MikeML

    AAC Fanatic!

    Oct 2, 2009
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    If the purpose is to make the motor run when the switch is closed, why not just bypass the photo board and use the switch to feed power to the motor? I'm assuming that the photo board works ok independent of the newly added switch?
     
  5. Chills24

    Thread Starter Member

    Nov 10, 2008
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    Yes the board works independent of the switch. The motor runs on 3v and needs more current then is available from the 5v power supply. So I would have to build a whole additional circuit to regulate power and run the motor which seemed like a lot for this. Th CB provides regulation and the power supply to the board is 9V.
     
  6. Duane P Wetick

    Active Member

    Apr 23, 2009
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    Probably a DIP reed relay, w/ 3-15 v coil is your best bet. Small pkg. and easily wired too. Just add a small switch to activate the coil from 5v supply.
     
  7. Bernard

    AAC Fanatic!

    Aug 7, 2008
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    If you are already using a PB switch, why not use it to short photo transistor?
     
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