Amp Draw Vs. Intensity

[Shubb]

I wanted to run a test to see how lowering intensity of a channel affected amp draw.
I connect a couple of 100 watt bulbs and a mini tree (100 mini light) to a channel and set up a test sequence. I ran full on for 30 seconds then 15 seconds at each power level from 100% to 10%)
I rounded the voltage, amps is actual.
Static was 116.5 volts 1.59 amps (plugged straight into wall outlet.)

Here are the results:

% Volt Amps
100 114 1.59
90 103 1.47
80 93 1.40
70 82 1.29
60 69 1.17
50 56 1.04
40 42 .88
30 29 .72
20 18 .55
10 9 .36

At 30% the lights were so dim I could barely tell they were on, at 20% I couldn't tell they were on, but still drew 1/2 an amp!

Scott

[Ponddude]

Wow...thats great to know. Thanks for doing that!!

Greg

[Jeff 1S.A.H.D.]

Cool good to know

Thanks

Jeff S.A.H.D.

[Steven]

Thanks for getting these numbers!

I searched around a bit and found a scientific explanation: Apparently an incandescent bulb emits light in wavelenghts close to ideal black body radiation. This means that the color emitted by the bulb depends on its temperature, which in turn depends on the current through the filament. At 30%, the color temperature will be almost all infared, which is not visible to human eyes.

[J.D.]

With this in mind, that means that having my LOR controllers configured to never fall below 3% intensity (using the Hardware Utility's Configure screen) to pre-heat the filaments continues to use quite a bit of electricity (I have 304 channels). Maybe I need to rethink this policy...

J.D.

[Jeremy Wiles]

I'm not an expert at this, but i've read in the past threads like this. People much smarter than me have indicated that numbers like that are not necessarily true. Something about how the meter calculates the amp draw and the fact that to dim we are clipping the sine wave.

In other words, because we are clipping the sine wave, the meter can't fully detect the amount of amps we are drawing.

I will try to find the other thread in the archives when I get a chance. Just know that according to the aforementioned smart people, dimming by as little as 80% is a huge savings in amps...

J.