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Power Supply's LM7812 regulator

bigone5500

Well-Known Member
I have a LM7812 regulator. I want to use it to build a step down power supply to power my LEDs from my 24v PSU inside my ender 5 printer. I connected the regulator with a 1uF capacitor and 1N4004 on the input side and .22uF capacitor on the output side. I get my 12v but the regulator generated a substantial amount of heat. I am currently drawing 245mA of current to the LED strip. The heatsink is giving off about 145F temps. I wonder if it's just not going to work. The regulator is rated for 1.5A. Maybe I need a larger heatsink?

20201220_152821.jpg

1x5/8x5/8"
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Output waveform
20201220_140823.jpg
 

Tony

Administrator
Staff member
So 145 is actually not that hot. It's only 62ºc to 63ºc, which is perfectly fine for electronics. Take a computer for example. When you are gaming on a computer, the CPU regularly runs 70c+ for extended periods of time. So I would not be at all worried about that temp. If you are, you can put a micro fan on it to passively cool the chip and see if that helps. I'm guessing with a fan, you would see about a 10ºc drop.
 

bigone5500

Well-Known Member
I think when I get back to that project, I have some larger heat sinks that may do a better job of dissipating the heat. That one was simply easy to grab and bolt on. My others are in the storage. On that note, I have found a 12v 5a PSU that will fit into the housing of my Ender 5 nicely. $10 and I'm done.
 

Tony

Administrator
Staff member
Nice! It's always fun to build the things, but sometimes, it's just nice to drop a few dollars and call it done!
 

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