PSU - Info

[Burgerman]

24.

Its not about best. You dont want it to swap from one to the other.

[ex-Gooserider]

I bought this 30V PSU. It looks sturdy and high quality.
https://item.taobao.com/item.htm?id=19995041970

I have some questions about this PSU:
1. I see 4 terminals +S, -S, SHARE BUS, ON/OFF in the center. What are they and what do they serve for? If it is unused, should I insulate them or leave them alone.
2. I worry about the non-insulated AC input terminals. Is there any solution to insulate them?

Not sure about the share-bus or ON/OFF terminals. If I was guessing I would expect the ON/OFF to be some sort of remote control input to turn the supply on and off from an external switch. Share Bus might be intended to allow hooking multiple supplies in parallel to the same output bus - normally a bad thing to do unless the supplies are specifically designed for it...

The +/-S lines are easier as they are fairly common on industrial supplies... Technically you will see them called 'Sense Wire terminals' Basically they are a sort of 'load compensation' mechanism, which can allow for voltage drops across the wiring harness or changing load demand... Essentially if you need your supply to maintain a precise voltage at whatever device it's powering (as opposed to at the supply) you run a separate pair of lighter gage wires from the device inputs back to the Sense terminals. They don't carry any current, instead they act as a permanent volt meter so the supply can 'see' what the voltage is at the device - if it starts drawing a lot of current so that the voltage drop over the supply leads drops, the sense wires tell the supply to increase it's output voltage to compensate...

MOST electronic gear isn't that fussy, so generally they are not used. Some supplies like you to tie the sense terminals to the corresponding output terminals if not going all the way to the device. Supposedly this will make the supply output more stable. Other supplies just leave them disconnected.

The exposed AC input (and DC out for that matter) terminals are evidence that the supply was intended to go inside some other sort of equipment cabinet that would protect them... Obviously putting the supply in a box (with proper ventilation allowances) is the "best" approach... Otherwise you are on your own... As others have said, hot-glue or other covering would work. For something a bit more robust I'd look at trying to make some sort of cover that could either snap into what look like notches on each end of the AC terminal strip, or possibly go under the screws that hold the strip onto the cabinet...

ex-Gooserider

[snaker]

Thanks ex-Gooserider. Your explaining about this 'strange' PSU is very clear.