I'm looking for some input on a power supply problem...
I'm using a Mean Well LPV-60-36 power supply (output of 60 watts @ 36 volts, rated for 1.67A RMS) to power a DM542T stepper motor driver that's driving a NEMA23 stepper motor (rated up to 4.2A). The power supply is nominally marketed as a constant voltage "LED power supply", but my use case should be within its specs, and I need the IP67 rating to be used outside in Seattle's late Fall weather (it's for a Halloween prop).
As a baseline, this whole setup works fine when I'm running it off of my "cheap" switch-mode benchtop power supply @ 30 volts.
I'm facing a problem where the power supply seems to be triggering one of its overload protection mechanisms, and it shuts itself off until I power cycle with a ~60 second off time. The trigger is definitely instant velocity changes of around 20% or more (either positive or negative acceleration). The stepper motor driver has configurable current settings, ranging from 0.7A to 3.2A RMS. The problem seems to be more prominent when I've configured the driver to run at lower currents, and starts to go away as I run at higher currents near the power supply's rated output current limit.
I've put a 1000uF electrolytic capacitor (it's really 2 caps in series, since they're only rated for 35V each) on the motor driver's input / power supply output. This maybe helped just a bit, but the problem is still present.
I first suspected that a surge current was tripping the OCP, but I'm not able to measure it on any of my equipment. Using a multimeter in series in the circuit to measure amperage, the "max hold" mode never sees the current spike above what it was measuring just prior to the overload protection tripping - just under 0.7A, while the power supply is rated for 1.67A, so there should be plenty of headroom. Similarly, an AC current clamp meter on the power supply's input also doesn't measure a spike in input current. This doesn't seem to be over current protection.
I then measured the output voltage of the supply with my oscilloscope, and there's a fairly large ~1.6V peak-to-peak ripple when running the motor at higher speeds, but that doesn't seem to change when the overload protection is tripped. That's a much higher voltage ripple than what the power supply datasheet specifies, 150mV peak-to-peak, which is suspicious.
Is a "LED power supply" nominally different than a "standard" power supply? Maybe the power supply is tuned for the load characteristics of LEDs, but the load characteristics of the stepper motor driver is just confusing its overload protection?