current limiting power supply as a load

[erdc]

I am in the process of testing out fuses with different amperages that will be going through them. I connected up a load resistor, and adjust the voltage from a power supply to get the current that I need. A co-worker of mine told me that I could do away with the load resistor, and dial in the current I needed form the current limiting power supply.

I thought a current limiting power supply was to be used when you did not want an excess of current delivered to a load, so as not to damage a test fixture. If I use it in my test set as is (just bare wires and a fuse) it would be a direct short. (we do have a 50A/50Mv shunt in series with the fuses though).

Can this be done, or is it hard on the power supply, especially when it starts to deliver 30 Amps?

 

[itsmoked]

Theoretically it can be done... I have done it many times.

It does creep me out though, so I do usually put some sort of resistor in the circuit just to cut the supply some slack. It can be any resistor that is a low enough value to allow the desired current and rated with a high enough power.

Then by all means turn the voltage up more than high enough and then creep up your current until Valhalla is reached.

If your supply has a current "control" knob rather than a "current limit" then it is designed to control to a specific current without harm.

A "current limit" supply could just fold back the supply to some arbitrary value when the "limit is reached".