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Zero Cross - Issue

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Designer
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2020/06/02 18:58:21 (permalink)
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Zero Cross - Issue

I'm dimming two incandescent light bulbs using zerocross detecting with a PIC & firing triacs.The attachment schematic works nicely at home.I get smooth dimming at home.
 
But when I plug the circuit in a factory, the lampls flickers mostly.While fading its flickering.
How to overcome this?

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#1

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    ric
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    Re: Zero Cross - Issue 2020/06/02 19:13:46 (permalink)
    +2 (2)
    I would guess there's much more noise on the power circuits in the factory.
    Is it possible to try it in the early morning/late afternoon when all the other equipment is off?
    Some sort of filter on the power going to the triacs might help if that's the case.
    (Or it might be noise getting into your zero cross detector. Can you watch that with a scope at the factory?)
     

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    OscarTheGrouch
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    Re: Zero Cross - Issue 2020/06/02 19:20:36 (permalink)
    +1 (1)
    Designer
    I'm dimming two incandescent light bulbs using zerocross detecting with a PIC & firing triacs.The attachment schematic works nicely at home.I get smooth dimming at home.
    But when I plug the circuit in a factory, the lampls flickers mostly.While fading its flickering.
    How to overcome this?

    Looks to me like you are using full wave rectifier. That means you are getting 120Hz to the transistor not 60 Hz.
    Maybe that is your issue?
    OtG
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    ric
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    Re: Zero Cross - Issue 2020/06/02 19:28:40 (permalink)
    +2 (2)
    Also, is the power coming in on the left guaranteed to be the same phase as the power coming in on the right?
     

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    Re: Zero Cross - Issue 2020/06/02 20:37:11 (permalink)
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    Thanks.
    Here we have 50Hz,so when its fullwave I have calculated my timings to 10mS periods.
     
    RIC is correct.I would take my oscilloscope oustside and check the waveforms how I get.We have only single phase in both locations.
    post edited by Designer - 2020/06/02 20:41:38
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