fechter wrote:Here's the datasheet for the switching controller chip:
Looks like the error amp inputs are pins 1 and 2.
If I stare at the pictures long enough, I can probably trace it out.
I also see an optocoupler. These usually tie into the feedback,
fechter wrote:It's pretty hard to trace from the pictures. Do you see anything that looks like a shunt?
My guess is raising the voltage on pin 2 will reduce the output. You could possibly try using a resistor like 100k from pin to the positive output and see what it does to the output voltage. You really want to feed just a little over 2.5v to pin 2 so you need to be careful with jumpers during testing. I think the chip fries if you put a little to much into there. There is probably another part of the regulator circuit that uses the LM358 and that feeds into pin 2.
Near the adjustment pot, there is a spot marked OVP. That might be the 2.5v reference spot.
On most meanwells, the sensing line is connected to one side of the adjusment pot.
The connector has pins marked S+ and S-. These might be remote voltage sensing inputs. You might see what the voltages on those pins look like.
The pins marked RC seem to go to the optocoupler and must be a remote control of some sort. Feeding voltage into the RC input might lower the output voltage. I suspect it's a 5v signal there.
steveo wrote:hey fechter
I see the shunt wires on the opposite side of the capasitors, 3 shunt wires on this psu
do you mean use use a 100k resistor connected to pin 2 on that chip & connect it to the 48v dc output of the power supply?
sounds like that will make things crispy...
steveo wrote:Hey Everyone
i just purchased 2 1000w meanwell 48v psu
i am having the issue where i connect the psu to a load (my batteries) and the psu powers down.. I've had the same issue with a small 250w psu which i fixed with one of fechters mini meanwell limiter boards....
I was wondering if anyone could help me on where to connect the sense wire for the limiter board on the 1000w meanwell
here is a couple photos of both sides of the psu board
steveo wrote:Could anyone specify how to increase current limit for the limiter board?, my power supply is 20amp at 48v however i only get 14amps at 48v off the limiter board...
hillzofvalp wrote:Yeah that's what I was talking about.. I do not need to limit charge limit cause a123 m1 cells handle 4C alright
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