harbor freight dimmers

smelni

smelni

Veteran
Based on recommendations here i purchased some of the harbor freight router speed controls to use as dimmer. I am finding that they audibly buzz at about 80% max and below. At about 50% it is very loud - i was testing with a 1000w light. It seems they will only be useful far from recorded sound.

ANyone else have this experience?
 
I haven't had a chance to test in multiple scenarios...but I have never had any problem with mine yet.

On another note can anyone explain how light changes color when dimmed, any articles to point me at?
....D....
 
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http://www.3drender.com/glossary/colortemp.htm
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Modern dimmer switches use a transistor to rapidly turn a light on and off so that current flows through the light on only part of the A/C cycle. This is significantly more efficient than old dimmers which used resistors, and it generates a lot less heat in the switch itself. The use of a modern dimmer switch on an incandescent light will reduce the power used by the light, decrease the temperature of the bulb, and extend the bulb life. However, such a light operating at decreased power will be less efficient at generating light than it would be at full power (e.g. at 50% power, you might output 30% of the lumens you would generate at full power). This reduction in efficiency is due primarily to the efficiency effect in the light bulb itself, with the dimmer contributing only a small amount to the reduction in efficiency. Dimmers should not be used with fluorescent lights unless the lights have been specifically designed to work with a dimmer. Most fluorescent lights are not designed for such use, and those that are are specifically described as such in their technical documentation.
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I hope this helps. It says that reducing the amount of light via a dimmer will lower the temperature, but I could not find anywhere that said how much % dimmed = how much of a temperature drop.

I would doubt a tweak in a light output would render a huge difference, but a severe dimming might. If you are very worried about it I would recommend you pick up this little bad boy, and once you figure out the difference on set you could gel those lights back to what you want. http://www.bhphotovideo.com/bnh/controller/home?A=details&Q=&is=USA&O=productlist&sku=35492
 
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I too have had slight problems, but not with hum. Interference with our wireless mics was our issue. Try plugging your stinger into a different room further away from set. What fixture are you using that creates this problem....a practical, one of your mole or arri lights, does it happen everytime and at every location ???
 
=Prodigy= said:
I hope this helps. It says that reducing the amount of light via a dimmer will lower the temperature, but I could not find anywhere that said how much % dimmed = how much of a temperature drop.

I would doubt a tweak in a light output would render a huge difference, but a severe dimming might. If you are very worried about it I would recommend you pick up this little bad boy, and once you figure out the difference on set you could gel those lights back to what you want. http://www.bhphotovideo.com/bnh/controller/home?A=details&Q=&is=USA&O=productlist&sku=35492
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Many thanks! I'll take a look at this info and see what I can extract from it.
...D...

p.s. that meter is pretty slick.
 
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Hi:

I have used as many as a dozen of them to light up an entire room and have not ran into any sound issues. Wonder if you are isolating your audio? Is your camera on battery or AC? Audio mixer (if you are using one?) on batteries or AC? Are you audio cables crossing or running parallel with with your stingers that the dimmers are on?

There are a lot of ways to solve an issue like this.

Best,

Dan
 
Hi Smelni,

At 80% or less, I could barely hear a slight buzz when connecting the Harbor Freight dimmers to a 800 watt Tota. Strangely, I did notice that when I squeezed and tried twisting the case, the amplitude of the buzz varied a bit. I also noticed that when I tried these bizzare maneuvers and adjusted the potentiometer, it also made a slight change in the low-level pitch and amplitude but was never audible more than a few feed away from the unit and seemed to subside in a short time.

I suspect the unit might be more noisy either under maximum load (15 amps) or if the potentiometer (or another component of the circuit board ) isn't making a good electrical/mechanical connection - just a guess. Maybe sometime I'll plug in a few lights equaling 15 amps to a terminal strip and connect them up to the dimmer. If the house doesn't burn down, I'll keep you posted...

Regards, Michael
 
I just used 4 of these on set this week we strung like 10K of arri lights and even paired 2 650s on one dimmer, no buzz or other issues at all.
 
I plugged a 1000 w light into the dimmer and then dimmed it - the light buzzed very audibly - i didnt need to be on a set to hear this
 
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