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3904 NPN transistor to drive a relay

Discussion in 'Electronic Projects Design/Ideas/Reviews' started by spestis, Jul 26, 2006.

  1. Roff

    Roff Well-Known Member

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    It's collector and emitter swapping that will give you marginal results, not collector and base.
     

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  2. kurrodu

    kurrodu New Member

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    Ron,

    Now I realized that the circuit works fine as long as there is no load attached to the relay.

    The load that I have is 240VAC 40Watt bulb.

    I think there is noise that is being generated. So do you think there would be any protection circuit for this?

    My friend asked me to look at weber circuit.
     
  3. kurrodu

    kurrodu New Member

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    Thank You all

    Finally, I have used an opto coupler MOC 3021 and a triac Bt139 that solved my problem.

    Thank you all for the support.
     
  4. dave

    Dave New Member

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  5. Tom81

    Tom81 Member

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    I know this post is a few months old now BUT... I had a similar problem a while back - http://www.electro-tech-online.com/threads/driving-relays-using-pic-16f88.97988/

    Opto coupling is definitely the way to go for reliability, although if this is not an option (IE too expensive) have a look at the above thread. Might give you some ideas.
     

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