Author Topic: RF Controlled 12V LED Light  (Read 1068 times)

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Offline MadScientist267

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RF Controlled 12V LED Light
« on: May 20, 2013, 06:53:33 PM »
This one was fun, and turned out pretty good...

26 LED Remote control light fixture for the van. Puts out plenty of light, although the color temp is a bit chillier than I'd really like for it to be, but it does the job, and certainly draws much less power than the inverter driven counterparts.

First, I started with a cute little module that I obtained from wally world some eons ago.  They are one of those "as seen on TV" toys called the "handy switch". I'd like to get more of these, they're handy for all kinds of things. This being one of them. They have excellent range (over 200 ft easily, but aside from a cool parlor trick, that kind of distance is pointless - the beeline distance is all of 3 feet)...



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Inside, there's a daughter board with everything needed to control something like this with no more than 3 connections (plus the antenna). More on that in a few.



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There are a total of 26 LEDs in use, 24 rather chilly, the other two warm. I would have rather had more warm than cool, as they are more gentle on the eyes and they don't "reach out" and light up the area around the van when there's a door open, but whatever, they work.



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In the original battery compartment is a buck converter used to control power going to the two original warm LEDs, as they were not designed to run on 12V directly. This also provides a little bit of color temp tuning, albeit minimal since there is such a difference between the numbers of each type of LED. Its there mostly now to just control the power.



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A closer shot of the 2 warm LEDs on their board, not much to see.



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Here it is with everything that was originally part of the sconce except the warm LED board removed. There's plenty of room for goodies inside and such with only these components installed.



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Next came drilling the holes for the additional LED strip wiring to pass through the case. There are a total of 4 added behind the secondary diffuser, so I drilled them so as to hide all the wiring as much as possible.



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Here the 4 additional strips have been prepped and strung through the holes for the wiring. The surface of the sconce was cleaned thoroughly with 97% alcohol to ensure they stuck properly. Between the two sets, the primary diffuser for the warm LEDs can be seen, although only the one on the left is actually visible due to glare.



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Shown here is the wiring routed up into the original battery holder on the back of the sconce. Things started to get tight in there at this point, but it all still fit. The wiring for the 4 extra strips runs to the input side of the buck, as they are designed to run directly from 12V.



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The final addition to the inside of the original battery case was made by adding the MOSFET that controls the power to the whole thing. Nothing special there, just an IRF510, primarily because it saturates with a Vgs of about 4V, the gate signal is 5. The current is of course so low that it doesn't need a heatsink either, so its just held in place by a blob of goop.



Continued . . .
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Offline MadScientist267

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Re: RF Controlled 12V LED Light
« Reply #1 on: May 20, 2013, 07:07:16 PM »
. . . Continued

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Here is the receiver from the "handy switch". Above it is a 7805 regulator, and off to the right, you can see that a resistor lead clipped all the way to the nub and carefully bent just enough to solder into the hole on the board makes a nearly ideal 2.4 GHz antenna with little other consideration necessary.



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The unit completely assembled, with the secondary diffuser put back in place. Not bad for some hacked up wally world parts that I threw a total of maybe 40 bucks at over the course of a few years if I don't say so myself.



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One shot of the lamp operating.



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And another.



All in all, pretty good light output. Uses in the neighborhood of about 2W or so when running, so it doesn't put much of a dent in the battery charge at night either. ;)

Steve
Wanted: Schrödinger's cat, dead and alive.