gar
Senior Member
- Location
- Ann Arbor, Michigan
- Occupation
- EE
170202-2436 EST
Electric-Light:
I will have to run an experiment. It would have been a recent Cree 9.5 W with heat vents.
George Stolz:
What problem have you had with a CL dimmer? It is a forward-phase dimmer just like a "conventional" dimmer, but it has better control of the turn on phase angle under different starting conditions. Specifically a low dimmer setting at the time of application of input voltage comes back with essentially the same intensity as before removal of power. Many conventional dimmers don't turn back on at low settings.
All Triac or SCR dimmers are of the forward phase type.
A three wire forward phase dimmer is better than a CL when you look at the output waveform, but I did not see a functional difference in dimming a Cree 9.5 W bulb between a CL and the three wire unit.
A three wire dimmer requires a neutral whereas a CL does not.
al hildenbrand:
A Triac or SCR does not turn off at a voltage zero-crossing unless the load is a resistor. What it really does is turn off when the load current falls below the holding current of the device. In other words it turns off at a current zero crossing no matter what the load is. For a Triac if the rate of change of current is too fast, then it may not turn off thru the zero crossing. Inverse parallel side-by-side SCRs are better in this respect.
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Electric-Light:
I will have to run an experiment. It would have been a recent Cree 9.5 W with heat vents.
George Stolz:
What problem have you had with a CL dimmer? It is a forward-phase dimmer just like a "conventional" dimmer, but it has better control of the turn on phase angle under different starting conditions. Specifically a low dimmer setting at the time of application of input voltage comes back with essentially the same intensity as before removal of power. Many conventional dimmers don't turn back on at low settings.
All Triac or SCR dimmers are of the forward phase type.
A three wire forward phase dimmer is better than a CL when you look at the output waveform, but I did not see a functional difference in dimming a Cree 9.5 W bulb between a CL and the three wire unit.
A three wire dimmer requires a neutral whereas a CL does not.
al hildenbrand:
A Triac or SCR does not turn off at a voltage zero-crossing unless the load is a resistor. What it really does is turn off when the load current falls below the holding current of the device. In other words it turns off at a current zero crossing no matter what the load is. For a Triac if the rate of change of current is too fast, then it may not turn off thru the zero crossing. Inverse parallel side-by-side SCRs are better in this respect.
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