What is the difference between thyristor dimming and MOSFET dimming?

Thread Starter

Young2

Joined Dec 7, 2020
94
If the luminaire's driver power supply has been written to support the cut phase set light, then whether to use the dimmer silicon or MOSFET dimmers?
 

DickCappels

Joined Aug 21, 2008
7,905
If the controller expects the early part of each cycle to be (variably) cut, a triac would be an excellent choice. If it expects the later part of the phase is to be cut (which would be a rare case) then you need something you can turn off easily like a MOSFET or IGBT.

Most likely you need a triac.
 

crutschow

Joined Mar 14, 2008
27,956
Thyristor control only works with AC.
MOSFET diming can be used with either AC or DC (depending upon its design).
MOSFETs are also more efficient for low voltage diming.
 

DickCappels

Joined Aug 21, 2008
7,905
Since Youg2 mentions phase cut dimming, I think this can only be done with AC, but yes, MOSFETs are easier than thyristors when switching DC -it is far easier to turn off MOSFETs.
 

Thread Starter

Young2

Joined Dec 7, 2020
94
If the controller expects the early part of each cycle to be (variably) cut, a triac would be an excellent choice. If it expects the later part of the phase is to be cut (which would be a rare case) then you need something you can turn off easily like a MOSFET or IGBT.

Most likely you need a triac.
Very good explanation, thanks a lot!
 
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