Bucking Supply Problem

[Andrew124C41]

I have a number of PSUs. Linear and switching I use for my Amateur Radios. They are working. One of them I made with 2 modified HP server supplies in series. I get 24 v.

I connect this to a Chinese dc to dc buck converter. It has a display and had a cc cv functionality.

I put an ASC 4500 on a high power dummy load st at 8.4 volts and for up to 8 amps. I could not get the driver over 1 amp. But when I tried 2 lithium ion batteries, I could easily set it.

I have no idea happened to my Buck controller.

Any ideas

 

[RedCowboy]

Your HP PS may not see the laser diode driver as a sufficient load, try putting a automotive light bulb on each PS as an additional load, parallel with your laser diode driver or as I suggested simply use good quality fully charged pair of cells, such as 2 x 18650 cells.

 

[Andrew124C41]

The HP supplies are in series with an output of 24 volts. The output goes to s bucking Supply regulator. It can be set for voltage, max voltage, amperage, and max amperage.

So, I think it is the controller