SMTmax CA18303D power supply turn-on spike

[TD-Linux]

I have had a CA18303 30V/3A dual linear power supply for a while. However it's burned me enough times that I thought I'd warn people about it. There's not many search hits for it, but I suspect it's the same internals as many other cheap linear power supplies.

The main issue with it is a massive turn-on spike when in parallel mode - I've measured it at 18V when set to 5V, though it probably sometimes goes higher as I've blown up chips rated for 28V with it. In theory, I can remember to attach and detach the load before turning it on, or always turn it from 0V to the setpoint. In practice, I've forgotten one time too many, and I'm about to replace it with a much nicer switchmode supply.

I've also previously managed to fuse the serial/parallel relays and replaced them. I also broke the handle at one point and replaced the cracked plastic with a 3D printed part.

Bums me out a bit to waste such a nice toroidal transformer and otherwise decent construction on a flawed design.