Hello,
I’m looking for a 12v true 2A power supply. Ready to use or DIY parts.
I’ve bought a led projector from GB that uses 12v 2A power supply. I would like to be able to power from car lighter socket. I’ve tried using this plug with this converter. The voltage is set to maximum at the converter. The output voltage with engine working and no load is about 12.4v (forgot to take my DMM to measure it under load). The pojector is flickering like it does with cheap AC power supplies, probably not getting the needed current. Any possible fix or other options?
Something like this ultimate power supply should work for up to 10A… It depends on your cig. lighter fuse.
I have the same projector. I used a 19V laptop power supply (bought used ~$1.50) and the regular-sized LM2596 converter.
I see you’re using the mini-sized converter, I don’t know about how good it is but I suspect that might be the problem.
The question is how will the projector tolerate the higher voltage and noise. I’d rather not burn it trying.
+1 for those LM2596 converters! They work great in everything I’ve used them for. I power most of my high power (>1A) arduino and other around the house / shop projects with those things. Depending on yor driving style and the car you may find you get more consistent performance with a larger cap on the input side. If you’re getting dropout / flicker issues still you may also want to increase the output cap while your at it.
Edit: looked a little more at that mini converter that claimed “2A, 3A max”, there’s just no way, even if you heatsinked it super well. I’m guessing the buck iC has some tiny little internal FET, that’s the problem there I’d be willing to bet. The only time I’ve ever seen one of the big ones go bad it was the FET that blew, also the FET is the part you want to sink, it’s no wonder those things don’t perform.
A bit of heatsinking on the LM2596 also goes a long way in helping lower the flicker, remember those IC’s are thermally regulated and w/o heatsinking at 2A they get quite hot pretty fast
Thanks for the input. Now I’m thinking about buying a buck-boost converter It claims to have constant voltage output. Might use it both with the car adapter and battery pack (2s4p should be enough for a couple of hours).
WOW…that’s crazy cheap!
Looks like the only way to heatsink those is to epoxy a long bar heatsink (meaning like 1” long) across the top of the IC package on the component side.
Looking at that schematic and at the board, it appears the XL6009 is running in a fixed VDC out mode (aka it boosts whatever is coming in to it’s max output volts of approx 30~vdc), then the LM2596S bucks it down, the potentiometer is for the buck portion not the boost portion.
Notice the resistor divider off pin 5 of the XL6009 (to the right of the bottom IC between the IC’s…that is the fixed volts out from the schematic above, not connected to a potentiometer but a fixed resistor divider [wish it was clearer so I could identify the values])
very very cool board but I wonder how efficient it is
Here are some other pics I’ve found
I’m not good at electronics but If the XL6009 boost to its max voltage than the efficiency probably not so great. XL6009 is 92% efficient boosting 12v to 18v at 2A per datasheet. Nothing on second converter.
BTW the small board from BG is capable of supplying 2A at 5v output from 12v input. Tested for a few minutes, it stayed above 2A at 5.2v
Received the converter today. I don’t have a way to measure current ATM. So I did a runtime test :). I used 3 Panasonic NCR18650 cell to directly drive the projector, it gave me about 35 minutes before it started flickering and the cells were and 3.5V under load. With the converter the cells were down to 3v after 40 minutes. So no point of using it with battery pack. Might still be good for a car though.
According to HKJ Tests the remaining capacity at 3.5v is 15-20% so the efficiency is at 80% ballpark?
It gets very hot fast, I used a PC fan to cool it down and at 17C ambient temperature it was still quite hot to the touch