Switch mode PSU - can it cross the pond?

[Jules]

I bought a spare Epson C60 printer from the US, where 110 volts is the mains supply. Looking inside, I found it has a switch mode PSU (not a transformer). The fuse was rated for 230 Volts, but a smoothing cap was 400ufd, 200volts. My UK printer has an identical PSU. I think they are basically the same. Before I plug it in to the mains (and ruin it!) does anyone know whether the US version PSU will automatically select the different input voltage? (230V as opposed to the US 110V). My iMac computer DOES auto-select input voltages. Thanks

 

[Nigel Goodwin]

I bought a spare Epson C60 printer from the US, where 110 volts is the mains supply. Looking inside, I found it has a switch mode PSU (not a transformer). The fuse was rated for 230 Volts, but a smoothing cap was 400ufd, 200volts. My UK printer has an identical PSU. I think they are basically the same. Before I plug it in to the mains (and ruin it!) does anyone know whether the US version PSU will automatically select the different input voltage? (230V as opposed to the US 110V). My iMac computer DOES auto-select input voltages. Thanks

A SMPS has to be designed to work over that wide a range, this one obviously isn't - or it wouldn't have a 200V smoothing cap. Sticking 230V up it is likely to be catastrophic - with (as a minimum) the capacitor exploding!.

If it is 'identical' to the UK one, you may be able to just uprate the smoothing capacitor - but you need to be 100% sure that every single component is identical to the UK one - particularly the transformer, it must have exactly the same numbers on it!. You could well destroy both the PSU and the printer is not!.

 

[Sebi]

I agree with Nigel. Are You sure the capacitor not a 200uF and 400V?
400uF cap. useable for 500W PSU!

 

[panic mode]

Looking inside PSU for clues if it would work on different voltage
is not something I would recommend for most people because
it can be dangerous. Why not read the print on the side of the
PSU? It must clearly state operating range (90-150VAC 60Hz or
85-250VAC 50/60Hz). The first case obviously wouldn't work
while the later one would. Trying to determine operating range
by loking at capacitor alone is not good practice because often
they are overrated or it is not just one cap that does the job
(it's often two in series so together they can work with higher voltage).
For example this is used in PC power suplies so that input voltage can
be easily selected via simple slide switch.
Nigel is right. The safest way to run US PSU in Europe is to use transformer to lower the voltage. There are also small power
converters for travelers. They probably cost as much as your
printer ($50-70) so make sure to check for power requirements
next time you buy a product in different country.
Another thing to consider is approvals. I'm not sure if you would
have easy time explaining to insurance agents that your house
didn't burn down because of equipment lacking CE certificate
or your tinkering inside PSU.