Power supply has bogus load sharing capability?

[cupoftea]

Hi,
We are evaluating a 750W offline (100-265VAC) 24Vout converter for purchase. They tell us that it can do load sharing with other paralleled converters the same. They point to a UC3902 load share controller in the schematic. However, I have looked closer and see that the way they have connected the UC3902.....the UC3902 does not adjust the Vout of the converter. The converter’s Vout is adjusted by a microcontroller. This microcontroller also reads the converter’s output current. And the converters output voltage.

The micro does not read the “Share Bus” of the UC3902. Also, the micro takes in no signals from the UC3902. The micro takes in no signals from any other paralleled PSU.

Do you agree that this converter cannot be truly load sharing (with other paralleled converters the same as it) over the entire load range?

UC3902

https://www.ti.com/lit/ds/symlink/uc3902.pdf?ts=1641329266537&ref_url=https%253A%252F%252Fwww.google.com%252F

 

[Easy peasy]

Best way to achieve load sharing is passively - i.e. set all DC out the same at room temp, then have equal lengths of wire or resistive wire to drop say 0.3 V from no load to full load .... from each psu ....

 

[cupoftea]

Hi,
Thanks, that sounds like a good way. Regarding the UC3902, the ADJ amplifier doesnt connect to anything in the schematic, well, to nothing that could influence Vout. So i beleive that this is a dummy part in the schem. The ADJ Amplifier output just basically powers into a resistor that goes nowhere.