Hi,
From the Induction PWM controller thread, I need to be able to switch on AC line voltage after the +5V is already up. I used a MOSFET to drive a opto-triac driver chip.
This chip in turn drives the gate of the main triac to switch the AC line to the PWM Line input.
In the LTSPICE sim, the circuit works exactly as planned giving me a 100ms delay from 5V up to AC Line available to the PWM drive circuit.
When I built the circuit, the results were not the same: with R4 at 1k, the triac never turned on. As I lowered R4 value from 1k, I found that the triac was always on.
If I understand correctly, the triac needs a minimum load current to conduct fully. Since I don't have any way of knowing the load current, what AC switching circuit can provide a Line voltage switch regardless of the load current?
Does anyone in the Forum have a suggestion?
Thanks,
Neko
From the Induction PWM controller thread, I need to be able to switch on AC line voltage after the +5V is already up. I used a MOSFET to drive a opto-triac driver chip.
This chip in turn drives the gate of the main triac to switch the AC line to the PWM Line input.
In the LTSPICE sim, the circuit works exactly as planned giving me a 100ms delay from 5V up to AC Line available to the PWM drive circuit.
When I built the circuit, the results were not the same: with R4 at 1k, the triac never turned on. As I lowered R4 value from 1k, I found that the triac was always on.
If I understand correctly, the triac needs a minimum load current to conduct fully. Since I don't have any way of knowing the load current, what AC switching circuit can provide a Line voltage switch regardless of the load current?
Does anyone in the Forum have a suggestion?
Thanks,
Neko
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