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ZCD Circuit

Discussion in 'General Electronics Chat' started by tiwari.sachin, Nov 15, 2009.

  1. tiwari.sachin

    tiwari.sachin New Member

    Joined:
    Apr 20, 2009
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    Can anyone provide me the circuit for Zero Cross Detector. I need to interface it to PIC16F877.

    I dont intend to use a amplifier, rather a stepdown transformer, a fullwave bridge and the zener and transistor would be fine. I do know the concept and i think i am getting the circuit right too but i am not able to get the calculation for exact values.

    Kindly Help me out with the design for a ZCD


    Regards
    Sachin Tiwari
     
  2. Brevor

    Brevor Member

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    Location:
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    Google "zero crossing detector" there are lots of them.
     
  3. Sceadwian

    Sceadwian Banned

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    This topic has been covered in the forums on several occasions, no step down transformer is required, all that is needed is a single large value (1meg or more) resistor to limit the current and to chose an I/O line on the PIC that has clamp diodes. The resistor limit the current to the clamp diodes, the I/O line only ever sees the clamping voltage, an isolation transformer can be used if you need electrical isolation.
     

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