RE: Dimmers

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Mccauley, Daniel H" <daniel.h.mccauley-at-lmco-dot-com> 

 >  > Thats not entirely correct either.  The phase of the
 > output of a dimmer
 >  > switch is identical to the phase of the input.  A dimmer
 > switch merely
 >  > truncates a portion of the
 >  > original AC sinewave beginning at the first zero crossing.
 >  And since the
 >  > TRIAC is a latching device, once the TRIAC is turned on
 > and conducting, it
 >  > will remain on until
 >  > the next zero crossing at where this process will repeat.
 >  >
 >  > Dan
 >
 > 	That's not entirely correct, FOR A REACTIVE LOAD.  I'm
 > getting curious
 > about this and intend to run some experiments of my own.
 >
 > Ed

Actually, it is correct.  You are thinking about current phase in
relation to voltage phase.  I am speaking about
input-to-dimmer voltage phase in relation to the output-to-dimmer
voltage phase.  They are identical for any type
of load you put across there.  The only way this would change is if the
TRIAC pass element itself had enough of an
reactive impedance to vary phase and delay the output voltage a bit.

Dan