Meanwell RSP modificaitons

[Alexanderfoti]

Hi all

Had a search around, but couldn't find anything

Would it be possible to modify the max voltage of either the RSP-750-48 or the RSP-1000-48 just a couple of volts higher than their spec lists?

I think it should be easy enough to modify the resistance of the voltage pot (With inline resistor change) but I cant find any information or to see if anybody else has done in in the past?

This way, I Can pair them with my Eltek flatpacks to get 7.3kw charging at compatible type 2 stations.

Thanks in advance!

 

[fechter]

I haven't seen that model, but for sure there is a way to adjust things.

If you can post a good pic of the area around the voltage adjuster, it may be possible to trace it out. You want to find a fixed resistor that's between the low side of the pot and ground. Placing a resistor in parallel with that one will increase the voltage. It's best to do some measurements and some math first to pick the right value. If you go just a little too high, something will blow up.

Some models have secondary over voltage protection and that might kick in before you get where you want.

 

[Alexanderfoti]

Ok great, I will do thanks.

Any idea of the undervoltage limit on these? When I hook up at 114v String of these to an emtpy pack, they are going to see a pack voltage of 90v or so, and Im worried they will kick into under voltage protection?

 

[fechter]

They'll go into current limiting as the load tries to take infinite amps. Most of these supplies are not going to be happy running at the stock current limit for very long. Some way to limit the current to a lower value is generally needed to keep them from overheating or blowing up.

With multiple supplies in series, one will tend to go into limiting before the other(s). The voltage could possibly be driven to zero or even reversed on the one limiting. Reversed would be bad. You can do some math to figure out if this is something to worry about. If you have only two supplies in series, it's usually not possible as the pack voltage would never be less than the output of one supply. With more than two, it's a good idea to place diodes across the output of the supplies to prevent the voltage from going negative enough to damage the output caps. Normally the diodes do not conduct, but if driven negative they do.