Dimmer doubling quick and dirty. Basically the dimmer doubling adapter splits the AC waveform so that the "positive" side goes to one fixture and the "negative" to the other. The SCRs (or SSRs) in the Sensor dimmers are capable of chopping the AC waveform in a non-symmetrical pattern. Meaning you could chop half of the positive and 75% of the negative at the same time. In normal SCR operation the same amount of both positive and negative gets chopped.My god! I never knew.
I don't believe this has come up on CB before?
Does anyone here use dimmer doubling? I've read briefly about it, but am not positive about what the deal is with it. Can anyone shed some light on it? And why does dimmer doubling necessitate the move to a 550W lamp?
Dereks points are well spoken.Although I can see some advantages, personally I've never used it, as I feel the cons (special "two-fers," lamps, and connectors) outweigh the benefits. But I work in places that bring in as many dimmers as are needed for each show. .
The sine wave is chopped either way--that's the way SCR dimmers work.
Lower voltage = smaller filament = more of a point source = more LPW in an ERS.The most interesting thing to me is the fact that you get better luminous efficiency from lower voltage lamps. I don't know offhand why that is, but for the HPL575/115V you get 28.73 Lumens per watt, while the HPL550/77V gets 29.4 lumens per watt. I know that we had this discussion when I was in school, but I don't remember why it works out this way.
Also, as I said, there is a reason you get 77V from the DD system, but I don't remember what that is either.
dimmer doubles listed at $116.25From the ETC Dimmer Doubling Data Sheet: "77V HPL lamps have an additional pin that prevents you from installing them into a non-Doubled fixture."
Does this mean that all the fixtures that you use on Dimmer Doublers need different lamp bases? It also says that the DD's use 15 amp twist-lok connectors. I can see the cost adding up quite quickly. How much are the doublers themselves? Anyone have a rough estimate?
So yah twist-lock or you voild the UL listing, they do say that you can install them yourself though. NEMA doesn't actually list an L2-15P but the L1-15P seems to fit the 15A 125V two pole requirement. I found them for $9.00.
Two Pole, 3-wire would be an L5-15. Two Pole, 3-wire implies a grounded connection: two poles=Hot + Neutral, the third wire being ground. Besides, in this case it has to be a grounded connector to comply with code.