Looking for a non-switching power supply...

[shooter]

example with a 7824 with a coolingbody on it. costs 2 $.
A NTC (they are used in old CRT to to limit starting current)
A currentlimiting like the LM319.
a lightbulb is no good as it works when shortcircuit protection. (use it on my small railway.

 

[BobB]

Generally speaking, switch mode power supplies just shut down on overload to protect themselves. You generally then have to turn the input voltage off and let them settle before powering up again. Very normal.
I would comment that a 2 amp slipring is a bit short of the mark. I normally use 15 amp mercury sliprings - have never had a problem.
If the voltage drops too low the PLC will shut down - usually +15% -10% are the limits for most PLCs although some have a wider range.
Wish you could transmit power by wireless - no sliprings then! PITA!

 

[adisharr]

Sounds convincing, but I dont think it can be right. The manufacturers of current limiting PSUs specify the value that the current is limited to (like the one I linked to), and that value is not zero. So I am thinking that the PSUs have a little bit of intelligence built in. Such as, when the voltage cannot be kept even if the PWM is near 100%, then it assumes there is an overload situation and drastically reduces the PWM duty cycle. There must be a regulation loop of some kind.

You're right, I did drastically oversimplify the workings

I did some research with my scope and it looks like the (short circuited) output on my Omron supply stays at around 70mV. There's a repeating ringing that goes from 20mV to 130mV at a frequency of approx. 15kHz. Also, it looks like the duty cycle on some of the chips controlling the PWM section max out at about 45% or so