In Europe they rate internal combustion engines in kilowatts instead of horsepower. Both are units of power of course.
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Yes.ok but i just replaced every bulb in the house. all lites are dim able store brand from home deep,also EVERY lite is wired to older leutron skylark 600 watt dimmers . every thing works fine. sooo do i save on power when i dim the lites ??
1000 watt stage lighting? WTF. You've obviously never performed maintenance on an aircraft lighting system. I have. Rheostats are very common. In a series circuit, adding resistance reduces voltage, that's what dims the light.I'm sorry Glenn, but that is 100% wrong. No "in the wall" dimmers were resistive. They would never have fit. The 1000W stage dimmers had plates over a foot in diameter. They did not work by increasing the dissipated power. As I described above, they were used in SERIES with the load and the added resistance overall, decreased the current flowing and hence (since voltage was constant) the power.
Power = E**2/R. E is constant (120V). Increasing the load resistance changes the power consumed in inverse proportion.
As I stated, the main reason resistive dimmers were problematic, is that you had to size the resistance of the dimmer with the load to get a nice full range of dimming. Often theatres had to add phantom loads if they need to dim a smaller instrument. Resistive boards are real antiques. I restored one at the Utopia theater in Greenbelt, MD. They were quickly replaced in practice with autotransformers which essentially was a continuously tappable transformer which was smaller (albeit not lighter) and simply modulated the voltage which was independent of the load.
Actually the frequency is constant, but they turn on conduction of the semiconductor device at different portions of the waveform depending on the dimmer setting (essentially varying the duty cycle). They still run at 60HZ.
Semiconductor dimmers are more efficient than resistive dimmers, but it's not the case that resistive dimmers consumed as much power while dimmed as they did at full brightness.
ok but i just replaced every bulb in the house. all lites are dim able store brand from home deep,also EVERY lite is wired to older leutron skylark 600 watt dimmers . every thing works fine. sooo do i save on power when i dim the lites ??
I have no idea why you think 1000 watt stage lighting is odd. Most household dimmers are good for 300W. Some 600W or more.1000 watt stage lighting? WTF. You've obviously never performed maintenance on an aircraft lighting system. I have. Rheostats are very common. In a series circuit, adding resistance reduces voltage, that's what dims the light.
I don't have any idea who walter is, but the FREQUENCY is UNCHANGED. What changes is the protion of the wave form that current flows in. As I said, it's duty cycle. Full on is 100% of the wave form. Half bright is 50%. The frequency is unchanged. The only time variable frequency is used is to control induction motor speed.And I didn't say frequency (60 hz) was varied. I said the frequency of on/off was varied to control light intensity. (insert what Walter would say, here). Merry Christmas!
They were quickly replaced in practice with autotransformers which essentially was a continuously tappable transformer which was smaller (albeit not lighter) and simply modulated the voltage which was independent of the load.
Yeah, old TV cameras needed a lot of light. TV lighting all scoops and floods just put lots of uniform bright light on things.I used to take care of the critical electrical systems at a local TV station. Some of the legacy lighting and dimmers in the back junk room were crazy. It must have been close to a hundred degrees on the sets of early television newscasts.