Low-voltage DC-DC converter 16-75 VDC in; 12VDC @ 3A out
Here are some pics of the low-voltage converter that I created using the National Semiconductor LM2576HVT-12-ND buck-converter. The chip pretty much did everything for me -- all I had to do was to add two power-smoothing caps, a blocking diode, and a RF choke (which I mistaking undersized; promptly blew up and which I jerry rigged a loop of wire).
In the top left of the photo above, you will also note my premade, off the shelf 12VDC to 5VDC converter. This powers my LED headlights.
The following photo is the back side. Please note that I am a really lousy solderer. The LM2576HVT-12-ND will take any input from 16-75VDC and output a steady 12VDC @ 3A continuous but they mention that with active cooling it could do 5A continuous. That's 36-60 watts, plenty for me.
This is the wiring schematic that I used:
Top side again. The setup is small enough that my ESC and UBEC still fit in the project case with plenty of space for airflow -- and for another DC-DC converter to fit in there in case 3~5A is not enough.
The resulting low-voltage converter and ESC "mounted" on my bike with duct tape. This is an older photo, I've reduced some of the wiring and since changed the SB50 connector to a PowerPole 45.
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Re: Low-voltage DC-DC converter 16-75 VDC in; 12VDC @ 3A out
Looks great! Any idea as to how efficient it is?
Re: Low-voltage DC-DC converter 16-75 VDC in; 12VDC @ 3A out
Thanks! The spec sheet from National Semiconductor says it's 88% efficient.
Karen
Working on a Piaggio Boxer (mo-ped) EV conversion: http://gpsy.com/ev
Re: Low-voltage DC-DC converter 16-75 VDC in; 12VDC @ 3A out
Personally, I was disappointed - I thought you building a "real" boxer like on your logo :) My favorite dog ,BTW
But I can use the other info so all is forgiven :)
Re: Low-voltage DC-DC converter 16-75 VDC in; 12VDC @ 3A out
Shhhhh....... I am actually owned by a beagle, so don't let him know I'm working on a boxer!
Karen
Working on a Piaggio Boxer (mo-ped) EV conversion: http://gpsy.com/ev
Re: Low-voltage DC-DC converter 16-75 VDC in; 12VDC @ 3A out
Darn it, my servo tester blew. I'm not sure why, it was working one day and not the other. It rained a little bit, but a little rain shouldn't hurt an IC.... :-( Anyway, my boxer is on hold while I wait for another servo tester.
:-(
Karen
Working on a Piaggio Boxer (mo-ped) EV conversion: http://gpsy.com/ev
Re: Low-voltage DC-DC converter 16-75 VDC in; 12VDC @ 3A out
Karen, you have the worst luck... or is it that what we(you) are trying to do won't work reliably (use R/C components in a ridable EV)
Re: Low-voltage DC-DC converter 16-75 VDC in; 12VDC @ 3A out
I think I'm personally deadly towards integrated circuits plus I don't think all of these R/C components are all that "battle hardened."
I'll be sure to pot my next servo tester in some epoxy or silicone before it goes out in the field!!
Karen
Working on a Piaggio Boxer (mo-ped) EV conversion: http://gpsy.com/ev