dr_st wrote:

Good God, a PSU with a physical 115V/230V switch. Kill it! Kill it with fire!

What are you banging on about? I don't think I've seen PSUs of a certain age without that switch.

With the switch in 115v on a 230v line/grid the PSU will try to make 460v which blows out the first stage.

[Been a long time since I looked]
As I recall the switch in 220v on a 115v grid the PSU just sits there doing nothing but nothing actually gets broken.
Not all PSUs are the same so your mileage and the degree of smoke may vary.

----
Long time ago I talked to a High School instructor in Australia (230v grid).
In his school the students started pulling a prank where they moved the switch to 115v when they left the room.
When the next class came in and powered up the PSUs blew making a lot of 'fun' noise & smoke in the process.
Worked out an easy mod to disable the switches. Such a kill-joy I am...

[Edit]
Come to think,
I also suggested he connect the switch to a buzzer so he could bust the pranksters.
He liked the idea but it was too much trouble given how many he had to mod.
.

dr_st wrote:

BinaryDemon wrote:

Wouldnt that only kill it if you were in a country that actually supplies 230v and you had it set to 115v? I don't remember any issues with killing my hardware by flipping the switch *back in the day*.

Good question. Basically you're suggesting that 230V will kill a PSU expecting 115V, but 115V will not kill a PSU expecting 230V?

That's my guess, I don't think a psu switched to 230v and powered by a 120v wall socket will work... but I don't think it would damage anything either.

PCBONEZ wrote:

[Been a long time since I looked]
As I recall the switch in 220v on a 115v grid the PSU just sits there doing nothing but nothing actually gets broken.
Not all PSUs are the same so your mileage and the degree of smoke may vary.

I recall this being my experience as well. Like you say I guess it 'could' damage the PSU or components but I've never seen it.

badmojo wrote:

What are you banging on about? I don't think I've seen PSUs of a certain age without that switch.

Yeah, I know. They did not always support flexible 100-240V voltage. I think I might have one of these 'switchable' PSUs myself on my old system. I still dislike them. It is just bad design that a switch in the wrong place can cause the entire thing to blow instantaneously.

I guess that it is still better than the hardware (such as power tools, large electronics, etc.) which is just designed with a single voltage in mind and cannot work at all on different grids without voltage converters.

Come to think about it, though - how was the situation with old laptops (from that era)? I think that even "back in the day" their power bricks were rated for 100-240V. How come desktop PSUs didn't bother? Was it too expensive to implement?

dr_st wrote:

BinaryDemon wrote:

Wouldnt that only kill it if you were in a country that actually supplies 230v and you had it set to 115v? I don't remember any issues with killing my hardware by flipping the switch *back in the day*.

Good question. Basically you're suggesting that 230V will kill a PSU expecting 115V, but 115V will not kill a PSU expecting 230V?

Recently i made a mistake, i was working on a psu replacement and i asked the owner the voltage of the power outlet and he said it was 127v (here in my country 127v is used for low power appliances and 220v for high power adapter and 370v for industrial usage) and i switched the psu to 127v and the power outlet was 220v, the power supply worked and booted and after a while the psu exploded(the caps i guess because of the smell)
But the hardware survived.

dr_st wrote:

Come to think about it, though - how was the situation with old laptops (from that era)? I think that even "back in the day" their power bricks were rated for 100-240V.

Most were.

dr_st wrote:

How come desktop PSUs didn't bother? Was it too expensive to implement?

Desktops are not intended to be world travelers like laptops. There was not a need.