I don't have much experience with triacs. Suppose I am using an MCU controlled triac to switch AC current. I am NOT using phase-control, but rather am using the other kind...I don't know what it's called. It's where you let a continuous AC wave pass for a periodic intervals amount of time and then block it for every other periodic interval. I think it's called zero-cross control/switching? I forget.
Why is a momentary pulse ALWAYS used after every AC zero crossing to trigger the triac rather than a continous pulse throughout the half cycle? Sure, this is all that is required since the triac's conduction state will be self-sustaining as long as the AC signal has the same polarity as when the triac was switched on, but can't a continous pulse that remains active across AC half cycles also be used?but can't a PWM signal (that remains active during entire AC half cycles) be used to trigger the triac? The conduction time of the triac for a single PMW cycle would the active time of the PWM pulse plus the time until the next AC zero crossing (due to the 60Hz of AC powerlines and the self-sustaining triac conduction).
Is there some overbearing heat dissipation problem I am completely unaware of if a continous pulse is applied throughout the half cycle rather than just at the zero crossing?
Why is a momentary pulse ALWAYS used after every AC zero crossing to trigger the triac rather than a continous pulse throughout the half cycle? Sure, this is all that is required since the triac's conduction state will be self-sustaining as long as the AC signal has the same polarity as when the triac was switched on, but can't a continous pulse that remains active across AC half cycles also be used?but can't a PWM signal (that remains active during entire AC half cycles) be used to trigger the triac? The conduction time of the triac for a single PMW cycle would the active time of the PWM pulse plus the time until the next AC zero crossing (due to the 60Hz of AC powerlines and the self-sustaining triac conduction).
Is there some overbearing heat dissipation problem I am completely unaware of if a continous pulse is applied throughout the half cycle rather than just at the zero crossing?
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