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DIY Dimmer?


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I thought I could save a few bucks [more like a few hundred or more] by building a DIY dimmer.

More like, putting together the following from Amazon to make it "legit".

My enclosure
https://www.amazon.com/dp/B004TGYW46/ref=cm_sw_em_r_mt_dp_DDNEFX8Z7KMGPT2VSN8T?_encoding=UTF8&psc=1
My dimmer
https://www.amazon.com/dp/B07ZNVQ3HY/ref=cm_sw_em_r_mt_dp_MVG8FDS4HHVZTX51A655?_encoding=UTF8&psc=1
My cable gland connector
https://www.amazon.com/dp/B078RJXPVP/ref=cm_sw_em_r_mt_dp_SAB65ZHJEGPQ0PC7R2A1?_encoding=UTF8&psc=1
My plug connectors
https://www.amazon.com/dp/B00L7704O2/ref=cm_sw_em_r_mt_dp_YF9NYR484T64KGPA9YNM?_encoding=UTF8&psc=1
https://www.amazon.com/dp/B008SF1JAY/ref=cm_sw_em_r_mt_dp_D4X839GFKF2MZA69W7CZ?_encoding=UTF8&psc=1

I am one of the few people [suckers, perhaps] that bought a discounted Relamp 2K Daylight studio replacement bulb. Rather, it was the square version, which made fitting it into the Arri 2K tungsten fixture a gigantic pain in the ass. Nevertheless, the first time I wired it up, got magic smoke due to a solder bridge, by removing and resoldering the B500K pot lay flat instead of perpendicular to the board. Next, I burnt out the B500K pot when I rewired it again, back in the enclosure. Third time *was* a charm, and got it to work outside of the enclosure. However, only the last 1/3rd of the turn dims the light. When I closed the lid, I imagine it shorted out, because I blew off one of the bads and the bottom of the PCB was full of soot.

What I want is a 120V version of this, but don't see it available on their site:
https://cinelight.com/tungsten-light-accessories/light-dimmer-2000-watts

Has someone built something long these lines, or have a suggested schematic / link of something similar? Eventually I hope the rest of my fleet will be LED, but for now, I'm focused on this 2K tungsten fixture.

Thanks,



Todd

Dimmer01.jpg

Dimmer02.jpg

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That box is way too small for 2000 watts.

A 2k Dimmer will set you back $100.00 bux just for the dimmer. Then you'll need a 4.5"x4.5" box to allow space for the wires and air flow.

C-2000-BE.pdf?i=D082DE00-FDA1-4FBE-8F8A-
 

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I made a 2k dimmer with a Lutron rotary that matches the dimensions Ed said. I wish I remember where I got the enclosure, but i think it was a heatsinked design that seemed to work well. Even with that size, and using 12g wire, it was a chore to cram everything in there.

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If I was to pay for an electrician to build this for me I would make sure that there was-

-fuse protection to protect the electronics and user in case of a short circuit fault.

-the chassis of the dimmer was earthed, again for the safety of the user.

-the PCB was secured to the chassis in a more secure manner.

-Given how small the enclosure is, I would probably request some vent holes be put into the chassis to help with convection cooling.

-an on/off switch was installed- this helps you keep track of levels if you are just saving the lamp for a short period, or turning the lamp on to its set level on a cue. 

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1 hour ago, Matthew Parnell said:

-fuse protection to protect the electronics and user in case of a short circuit fault.

-the chassis of the dimmer was earthed, again for the safety of the user.

I would not ever use this thing for anything, ever, under absolutely any circumstances, without those two requirements being fulfilled.

It's not like it's hard to do.

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Noted — thanks for all of your insight. I usually work with much lower voltage electronics, and didn't think about some of this before I did it. Thankfully, there were no accidents.

Getting larger boxes with a grounding post, fuse receptacles, and Lutron 2000W dimmers specifically designed for dimming lights instead of slowing down motors with a PWM circuit. Guessing that circuit wasn't helping me use the full range of the rotary pot either.

Edited by sines
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29 minutes ago, sines said:

Noted — thanks for all of your insight. I usually work with much lower voltage electronics, and didn't think about some of this before I did it. Thankfully, there were no accidents.

Getting larger boxes with a grounding post, fuse receptacles, and Lutron 2000W dimmers specifically designed for dimming lights instead of slowing down motors with a PWM circuit. Guessing that circuit wasn't helping me use the full range of the rotary pot either.

If you were to simply put a machine screw through the case, with a star washer to ensure proper contact, then connect your earth wire via a crimp lug, I'd consider that a reasonable way of grounding it. On something like that you might prefer a countersunk screw, but ideally:

Image result for earth grounding lug

Fusing is easy, just get a fuse holder you can put through a hole in the side of the case.

Ideally get two, and mark one as just for storing a spare fuse.

 

 

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