200W RGB, silent, cheap, flickerfree, diffuse and spot

By: thebommel
Category: Blog
6. Januar 2021

I had a practical problem. To get a fancy colors on sets for background decorations, the offerings online are pretty unfitting to my needs .. they are either too weak, too loud, not flickerfree, to expensive, need to many accessories … you name it.

For me, the following criterias were important:

LED
min. 150watt
silent
flickerfree
the option to use it as a spot and as a flood light
should not break the back since they are just for deko
no small rgb diodes only bigger highpower ones since the small ones are crap
Sturdy

I bought 8 of these https://www.ebay.co.uk/itm/4X-200W-Stage-Light-U-king-RGB-54-LED-Par-Lighting-DMX-DJ-Disco-Party-Wedding-/223760845933

They had enough output and were flickerfree. But were spots and were too loud.

So i looked for a way to deal with the problems:

1. Flood option

This is ultra important. If you want a Cyan wall in the background of a stream, the spot simply does not do it … other lights had bowens adapter, diffusor boards but with 8 lights that was simply a way too big and unstable package.

So i made the diffusion myself.

I measured both the screws and the diameter of the light.

And ordered a Thumbscrew: https://www.ebay.de/itm/R%C3%A4ndelschraube-DIN-464-M3-M4-M5-M6-M8-hohe-Form-EDELSTAHL-A1-1-4305/400489726850?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649

And for Diffusion i ordered a matt acrylic glass: https://www.ebay.de/itm/135-00-m-3-mm-PLEXIGLAS-GS-Satinice-snow-DC-WH10-Matt-Rund/362921480213?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649

And that was it. now i have the same size but a affective flood and spot mode.

2. Silent Fan

The next step was more difficult. The old fan was a highpower 36v fan that sounded like a vacuum cleaner from the future.

All fitting silent fans are 12V, so i needed to add this little thingy:

It is a step down module that converts the voltage.

The problem was now that the light only turns the fan on when it gets to a certain temperature, so i could not simply mount it straight away and measure the output and trim it down since the light does not send any voltage.

So i needed a powersupply that has at least 1,5v more then the desired 12v for the stepdown module to function.

I did not need the 36v that the light provides since the stepdown module is not a analog trimmer/poti. It does the reduction by pulse width modulation, so it does not care how much voltage comes, it just hast to be a bit more than the 12v.

Okay i added the stepdown module, trimmed it to 12v and i was almost done.

Btw. order more stepdown modules than you need. They are cheap but often crappy, one simply exploded, as you see on the right.

The thing is, normally the fan would „suck“ the warm air out of the light but normally it is also mounted on a stand … so i tried turning it around so that is suck the cold air from the outside in. Just like with desktop pcs, some fans bring fresh air in, some bring the hot air out. I decided to got the way of letting more fresh air in. I tried the lights for half a day and since the fan is temperature controlled it is sufficient enough to cool it down that way. I do further tests an measure what way is the bast and update as soon as i can! MISSION COMPLETE!