Hello Sir/Madam,
I am engineering student making phase dimmer control using triac
The schematic is as attached
What I have observed that many times attached circuit stop working due to failure of triac
I am not sure is it because of di/dt or dv/dt failure.
In order to avoid this I have used triac of much higher rating (10A) even though current needed can be as low as 1A.
However the problem continues. I have observed that the failure is for transformer powered halogen lamp (inductive load?) and for ceiling fans.
It works satisfactorily for incandescent lamps.
Also I am sharing one more observation that if I connect glass tube fuse link in series with the load then the fuse blows.
From the various information available I realized that I need to use choke / inductor to overcome this problem. Is that right?
I need help to
1. To find out the value of the inductor for 0.5A, 1A and 2A
2. Is this a special type of inductor? if yes wish to know make
Thank you in advance
Dinesh
Replies: 12
You circuitdiagram is missing it hard to answer the question without that, but still will try....
This is over engineering, you probably need 25% more than peak current of yor load. 10A is more than enough
Inductive loads like motors are the most notorious ones beacuse they induce a back EMF (reverse voltage) back into the TRIAC if there are not protection circuits the it will damage the TRIAC
What is the rating of the fuse and where exactly did you connect it? after the switching side?
Not sure because we dont know your circuit yet. Also have you considered a snubber circuit?
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