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Issue with Single Phase to Single Phase Cyclo converter Circuit.

Hamidnawaz340

Jun 27, 2021
2
Joined
Jun 27, 2021
Messages
2
HI,
I am Hamid Nawaz and new at this forum.

I am trying to make a circuit for single phase to single-phase cyclo converter. Using Pic Micro Controller for Triggering Gate of Trails.

Triac -> BT151
Optocoupler -> MOC3021
For Trigring Triacs -> PIC Micro controller.

I was unable to find any circuit diagram with the Triac Driver part. After some experiments I found a method to trigger Triacs. The Problem When I try to Operate each bridge (Positive and Negative) separately both work fine but when I combine two Bridges in anti-parallel the fuse blows out.
I have checked much time, there is no shortage. Maybe I am not making the right circuit.

I am Using a 100 Watts Bulb at output and I don't have osciloscope available, I am not able to share output waveform. I have attached the circuit diagram of what I have made, I there is an issue with the circuit please suggest me the right circuit. Thanks
 

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Harald Kapp

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Nov 17, 2011
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This is probably a timing issue. An oscilloscope would come in really handy to analyze this.
When you connect the two bridges anti-parallel, I assume that you inadvertently activate both legs of the bridge and thus create a short circuit between the supply rails which in turns will blow the fuse.
upload_2021-6-30_7-51-3.png

Note that a triac has two anodes, A1 and A2, not anode and cathode. And please do use standard schematic symbols, like so:
upload_2021-6-30_7-52-47.png
This will make it much easier for us to read your diagrams.
 

Hamidnawaz340

Jun 27, 2021
2
Joined
Jun 27, 2021
Messages
2
Sorry for sharing the non-technical Diagram. I am using an 11 ms delay between triggering bridges.

Moreover, I have added a resister between the Gate and Cathode of each Triac. Also added a snubber circuit with each trace but the problem is still the same.
 
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