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[review] optotriac

Discussion in 'Electronic Projects Design/Ideas/Reviews' started by michal_w, Aug 9, 2011.

  1. michal_w

    michal_w New Member

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    Hello colleagues,
    I need to make a circuit to turn on a load resistor and then turn off ( I have to measure voltage with and witout load).
    I've attached my scheme which I want to use. The load resistor is R2. I want to connect R1 with microcontroller.
    Is it correct?
     

    Attached Files:

  2. MrAl

    MrAl Well-Known Member Most Helpful Member

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    Hi,

    Im not sure if those opto's you are talking about using here are made for continuous load handling like that. Some of them are made just for firing a regular triac. You might want to double check the specs.
     
  3. michal_w

    michal_w New Member

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    So, what should I use? I want to turn on and turn off the load resistor when I want, not when it cross zero (like using thyrisotrs or triacs).
     
  4. dave

    Dave New Member

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  5. MrAl

    MrAl Well-Known Member Most Helpful Member

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    Hi again,

    What kind of load are you trying to drive, it is just a resistor? What value?
     
  6. michal_w

    michal_w New Member

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    Only resistor 100 Ohm - 1 kOhm.
     
  7. crutschow

    crutschow Well-Known Member Most Helpful Member

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    The MOC3020 can only switch 100mA max. so the maximum V1 supply voltage you could use with a 100 ohm resistor would be 10V. If you want to switch more current than that you can go with a larger DC output solid-state relay.

    Edit: The MOC3020 also has a triac output so it will switch at the zero crossing. If you want it to switch otherwise you will need a DC output solid-state relay.
     
    Last edited: Aug 10, 2011
  8. MrAl

    MrAl Well-Known Member Most Helpful Member

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    Hi again,

    Is your source voltage really AC or could you use DC, and what level is it (volts)?
     
  9. michal_w

    michal_w New Member

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    I have to measure the output voltage of a transformer with and without load resistance.
    Voltage range is 10-15 V.
     
  10. Mr RB

    Mr RB Well-Known Member

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    A relay?

    Or a FET or transistor that connects the resistor to the transformer secondary using a diode bridge?
     
  11. michal_w

    michal_w New Member

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    Hello,
    thanks for your replies.
    If I will use solid state relay is it possible to switch off the load resistor in any moment of the time (like in attached picture) ?
     

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  12. crutschow

    crutschow Well-Known Member Most Helpful Member

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    As I stated in my previous post, you need to use a DC output type solid-state relay.
     
  13. 4pyros

    4pyros Well-Known Member Most Helpful Member

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    Ya but thats an AC wave form in his pic. I must be confused.
     
  14. crutschow

    crutschow Well-Known Member Most Helpful Member

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    A DC output solid-state relay is usually bipolar so it will also control AC.
     
    Last edited: Aug 12, 2011
  15. michal_w

    michal_w New Member

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    Hello,
    thanks for your replies. I've bought AQY414 and now I'm designing PCB.
     

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