def215 wrote:i had a question fetcher, if i have a psu that has the overcurrent protection as hiccup mode, would i be able to use this board to stop it from going into hiccup mode so i can get a constant voltage and current for charging?
I have ordered two Meanwell S-350-48's and was planning on running two in series and bringing the voltage down on both to 41 volts.
Pack is 20s LiPo. 5A 1C charge 82 volt is 410Watt..not 350..is that driving them too hard or can they cope?
I understand that for current limiting..one board is fine. But what about the voltage.
What range of control will this board give?
Can I leave one PSU at 48 and bring all the voltage down with the board on the other?
Or easier to just buy and use two boards? or mod one with a multi turn pot to bring voltage down, and then do fine control with the other PSU with the board?
To complicate things...I am hoping to use these PSU's in two rolls. In series as above at 82 volt...4 or 5 amp, and also occasionally for a balance charge in parallel as a 38 volt PSU to drive a iCharger 3010b 1000W balance charger.
How can I achieve this as well the initial charging in series?
fechter wrote:El_Steak wrote:So for a 100V solution (4 x S-350-24) this would not work?
It would work, but could run out of compliance if the pack was really dead. If you installed limiter boards on two of the 4 supplies, it would have more compliance.
I'll try to explain differently: At 100v the supply with the limiter can only drop by about 10v when the current tries to exceed the set point. This still leaves you with 90v, which might give you more than the desired current and throw things into hiccup mode. You could also run the risk that one supply shuts down and gets fed in reverse by the other ones (causing failure). This would not necessarily be the supply that has the limiter board on it. All of these things would only happen if the pack voltage was significantly below 90v.
the supply with the limiter can only drop by about 10v when the current tries to exceed the set point.
NeilP wrote:Maybe it is Garys boards from tppacks that do the voltage control?
auraslip wrote:I used the BOM for the 24v boards. I didn't get the zener diode.... is that a necessary part for 24v boards?
fechter wrote:For over 35v operation, we just add the 24v Zener diode and no longer use the FET or 100K resistor.
For under 35v, place a piece of wire through the 24v jumper holes. You can use a piece of wire snipped off of one of the resistors. The jumper goes here:
For over 35v, place the zener diode like this:
It won't hurt if the zener diode is installed and the 24v jumper is added. It will be in the under 35v mode with the jumper.
For odd voltages, the value of the zener might need to be changed. To calculate, take the highest output voltage for the supply the board is connected to, and subtract 35v. This is the value you should use for the zener. If this doesn't work out to an available value, use the next higher zener voltage. Multiple zeners can be put in series to increase voltage. Try to keep the input of the LM78L12 between 24v-35v.
auraslip wrote:Second, instead of using a trim pot to adjust the current limiting resistor inside the meanwell itself could I jump it and use the current limiting boards only? I ask because I've been using the pots to control current, but with the proper cooling I'm at the limit at which the stock meanwell limits to.
auraslip wrote:Where/how on the board does it tie into the sense line?
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