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[uhtrinity]

Originally Posted by JimIsbell

I was just contacted with a bid of $13.67 for the Meanwell CC power supply. They could not quote the shipping but said it was just the UPS charge from Calif., no extras for handling. They are supposed to be sending me a quote by email. If anyone is interested, I can share it with you ...when I get it....

But at the same time I have just bought 10 of the 317 regulators for $6 (60 cents each) AND 10 each 2.4ohm 2 watt resistors for $3.50 which I will make into a current regulator that is switchable from 280ma to 560 ma with a single relay driven by a series resistance divider and a switching transistor with a second relay for a "latching relay" to keep it from backing up. There will be two 2.4 ohm resistors in series to set the current to 560 ma and the relay will short out one of them to drop the current to 280 ma. So for under $15 I can make 10 constant current regulators. This will go in series with 4 of the Meanwell 48V power supplies in series set to about 180V. Then it will automatically switch to the lower current when a preset voltage determined by the resistive divider is hit. The fans will be run from a 12V Wall wart that I got from the thrift store for $1 and it will connect to the AC pigtail so fans are on whenever the pigtail is plugged in. All automatic, in the battery compartment, with only a 115V AC pigtail out the back.

I ordered some of the LPC-20-350's for about $14.50 ea, but they are backordered for about a week.

On those lm 317's ..... you need the lm317hv. The LM317 will burn out if you try to span to great of a voltage range. I know as that was the first one i tried. I also tried the higher current version and they also burned out. The 317hv's have been running almost 2 years with no issues.