These power supplies are definitely not short circuit protected! Installing a dedicated power supply for the Cohesion3D Mini, plus rewiring the unit with # 14-awg stranded wire from the # 20-whatever-wg they had coming in so I can add some more components and accidentally fried my power supply.
I wanted to double check the positive 24v output before wiring in the second supply and someone in front of the house quickly revved the heck out of their motorcycle. I jumped and the multimeter probes briefly shorted across the positive and negative, and it seemed like it was ok, but then smoke came pouring out a few seconds later.
Not the best way to discover they don’t have short circuit protection.
Being an electronics nerd, I quickly found the problem. A 7812 regulator was scorched, but luckily I had some new ones in my parts bin, replaced it and the power supply seems fine now. Old vs new pics.
The mains wiring on my unit were not North American (110v/120v) adequate in my opinion. I have everything connected and working now. My secondary supply for the C3Dm is a 15 watt unit, which may be overkill, but I want to add some more things. Old vs new mains wiring.
Its strange that you blew the 12V regulator as it is only used to power the internal Hswitch drivers for the HV, its output does not leave the supply? The input of that regulator is connected to the 24V output so maybe something blew its input. Glad that fixed it though…
Your secondary supply is 15W? If that is a 24V supply that does not sound like enough to drive a K40?
This isn’t the first time I’ve had a situation with this supply. I was having intermittent problems and discovered a leaking cap, so I replaced them both. Looks like it was damaged and they used it anyway.
The big schottky diode behind the 12v regulator provides the 24v. If that blows then the 12v circuit looses power. The 12v is only used to feed the pwm chip to generate the high voltage. So definitely something strange going on here. Maybe and out off spec 7812?
