Bridge Rectifier over-voltage

[ThermallyFrigid]

G'day mates!

I am wondering if you could tell me why this KBU1010 Bridge Rectifier has an output of 342V DC (in circuit (no load)) with an input of 120v AC ?
The AC measured at the AC legs is exactly 120v AC.  But the DC output is far greater than expected.  In fact, almost exactly double the expected value.
I was expecting 121v * 1.41 = ~ 169.2v DC

Do I need to remove it from the circuit to measure these voltages?


Thanks

[bdunham7]

Does your PSU have a voltage selection switch?

[T3sl4co1l]

The explanation for the above comment being:



If it's made for 120V use only, it may be hard-wired this way, maybe with a jumper rather than a switch.

Tim

[ThermallyFrigid]

Hello,
This unit only accepts 110v - 120v
Schematic attached below

[ThermallyFrigid]

Thank you sir.
I'll re-examine the PCB and look for such a jumper or hard wiring.

[bdunham7]

Can you zoom out on that schematic?  It might be obvious if we could see the whole thing.

[Vovk_Z]

It may have an input auto-range technology too.

[David Hess]

It is configured as a voltage double to produce 340 volts DC from 120 volts AC.  This way it can support both 120 volt AC and 240 volt AC inputs by disabling the voltage doubling function.

[ThermallyFrigid]

https://www.industrial-electronics.com/re_elec-exp-hndbk_doublers.html