power

Sus

Member
2013-02-24 7:38 pm
I'm plowing though a bunch of stuff to build up a LM3875. Found one PS which was a bit high on V.60-0-60 NG. . Bingo, found a nice 400 W transformer. Ac out is 30-0-30. So now I have to build up a ps board. Anybody sell a PS kit or board to go with a LM3875 kit? Etching a board is a pita.

While I'm at it who can you trust to buy a kit from? Any good tech articles on mods for the LM series like the 3875? I think I need to bump the base a bit. Large caps etc help but anything else?
 
You could make it yourself by drawing the PCB in a cad program like Eagle or one of the many others. And then look on line for a boardhouse that does cheap prototype PCBs. You may find a deal like a new customer special and get it with solder mask and silk screen for less than you might think. Folks here can certainly help with the design. At least this way you won't get ripped off.;)
 
a Xformer 30v-0v-30v is a bit high for a LM3875 , it will give you about 42v DC which is pretty much the max the chip will take and if you mains fluctuates up even 5% it could cause the chip to shut down , plus the chip will run quite hot .... I personally wouldn't use a xformer higher than 24v-0v-24v for an 8 ohm load .....

PS: is it easy to make a basic PSU PCB just using a sharpie and a piece of PCB board or even a piece of vero board or even even wire it P2P , you can make a PSU with as little as 3 components (bridge rectifier and 2 large capacitors)
 
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