manikandan123
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In this type of application, using a microcontroller to control the triac, they have used L4004D3So when we choose a triac, we will want a small sensitive-gate triac capable of switching 4 amps. It should have a minimal hold current requirement so we can limit the amount of time that we will have to supply a gate current
Not even a BT134 usable in this circuit,need to have gate current drive of 3 mA and the minimum hold current less than 5 mA.
I couldn't reply you since I can't download anything directly from Microchip (and Texas Instruments).
So I couldn't have any clear idea about your circuit you like to apply.
I don’t know, need to have some schematics. Also better to read the previous thread.
Try doing this test:
Remove the load at the triac output (caution: the other two terminals MT1 and Gate are at the same potential of the remained power line).
Let the terminal of R8 at the side of GP2 pin be low (software or connect to ground, negative).
Measure the voltage drop on R8 (1.2K going to the gate).
You will likely get about 4.3V
So the triggering current is:
4.3 / 1.2 = 3.6 mA
None of my triacs (rated for 4A load and above) can be triggered properly by this small current.
So try to add in parallel to R8 another 1.2K resistor. It would double the gate current. And test again if the lamp light is steady. If not add a third one... and so on. Obviously when the load is made on properly, you will replace all resistors with one of equivalent value.
Kerim
Edited:
If the GP2 pin cannot provide the necessary current, you will need to add a simple drive to reach the triggering gate current.
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