Powering LM350 and 445nm off a 13.8v UPS

[robvdv]

I want to drive a number of LM350 and 445nm diodes off a UPS. The UPS will be powered by a two stroke generator. The LM350s are heatsinked and driven at around 1.2A. They'll be on continuously for 12 hours or so per day.

I hope that the UPS battery will smooth out voltage spikes caused by the cheapie generator and recharging inverter, but I don't know if that's the case. Does anyone here have any experience with this?

Also, is 13.8v too high to drive this circuit? I have the impression from my reading that "diodes set their own voltage and the linear driver will burn off the excess". Is that more or less correct, in layman's terms?

A side note: I have two inverters, one in my car and this UPS. Both seem to put out a lot of stray voltage/earth leakage. Is this normal/expected?

 

[DTR]

If you are planning on running 2 you might want to put them in series to reduce the voltage that is being dropped. Or if it is 4 or 8 try to work out a mix of series and parallel that will work with the available voltage/current the power supply can supply. Even if the LM350 could handle 14V that is a lot of voltage being dropped as heat if you just did a single or several in parallel.:beer:

 

[robvdv]

Thanks, DTR. I tried running it for around 15 minutes. The heatsink on the LM350 became hot enough to start melting the duct tape it was resting on.

Maybe I should just put on some really huge heatsinks and be done with it. This guy seems to drop 25W of heat this way: Special heat sink for an Lm350 voltage regulator.