Limit the current from a voltage source?

Question

Hi

How do I simulate/model the current limit of a voltage power supply?

Answer 1

Tim,

you'd need to combine an ideal voltage source with an ideal current source and switch between them. If the current through the voltage source exceeds your threshold current you'd switch to the current source. If the voltage across the current source exceeds the threshold voltage, you'd switch back to the voltage source.

An open current source will lead to a simulation error, so you'd have to short-circuit the current source when not used (or provide another path for the current).

Kind regards,

Oliver Schwartz

Answer 2

Tim, I'm sure you will have moved on from this problem now, but I'll post my solution in case someone else finds it useful...

I had a similar problem modelling a current and power limited capacitor charging power supply. In the end I replaced the voltage source with a current source controlled by the capacitor voltage. See model attached.

Regards,

Jonny