Printer power supply help please

spookylukey

Can anyone tell me what the electrical info on the back of a power supply means?

I have an HP photosmart printer that the power supply has broken on - on the back of the broken power supply it says:

Input 100-240v ~ 1A 50/60Hz
Output +32v - 940 mA
+16v - 625mA

I have tried the power supply from another HP printer and it does work but the 'new' power supply has different figures on the back and I don't want to use it if it's dangerous ie might cause a fire etc!

Power supply from other printer has:

Input 100-240v ~ 1A 50/60Hz
Output +32v - 700 mA
+16v - 625mA

The difference being in the output +32v my old one has the figure 940mA and the 'new' one has the figure 700mA.

Can anyone shed any light on what this means and whether it's OK to use it? Thanks in advance for any input

Taffybiker

If it were the other way round I would say there is no problem at all. The difference is not huge and I don't really know if it will matter that much. A lot will depend on your model of printer. That being said, any problems that might arise is likely to be the PSU packing in, since it may be asked to produce slightly more power than it can handle. The printer itself should be ok.

fwor

It's a relatively minor difference - the total power that it can deliver on the 32 Volt output is obviously less for the new power supply.

It's not possible to say for sure without knowing the maximum power consumption (in Watts) of the printer when working normally.

If you can find in the data sheet what its normal power consumption is and it's 30 Watts or less you should be fine.

Having said that, if it runs normally after the printer has been running for, say, half an hour, and does not get excessively warm to the touch, then you should be Ok. It's just another reason not to leave the printer switched on when not in use...

spookylukey

fwor wrote: »

It's not possible to say for sure without knowing the maximum power consumption (in Watts) of the printer when working normally.

If you can find in the data sheet what its normal power consumption is and it's 30 Watts or less you should be fine.

Thanks to you both for your replies I have absolutely no idea what volt/watt/amp/input/output means!

Here's the data for the actual printer...

Power consumption 25 watt maximum
Input voltage 100 to 240 volts, alternating current
Input current 1 A
Input frequency 50 to 60 Hz, grounded
Output voltage 16 to 32 volts, direct current
Output current 530 to 560 mA

fwor

Yes, that looks fine - at 25 Watts you should be well within what the new power supply is capable of (32W plus).

But keep a fire extinguisher handy (just kiddin').

Fifer

I'm not sure why the power supply lists two DC voltages (16V and 32V). It suggests that it might be switchable between the two (unless it's a dual supply rail which seems unlikely)? If so, perhaps the printer needs 32V and the replacement PSU is set to 16V.

EDIT: Just checked, looks like it is dual rail so ignore the above. What makes the OP think it's the PSU that's broken and not the printer? Obvious and basic, but does the mains socket that the printer supply is plugged into work?

spookylukey

Fifer wrote: »

What makes the OP think it's the PSU that's broken and not the printer? Obvious and basic, but does the mains socket that the printer supply is plugged into work?

When the original power supply is plugged into the printer the printer doesn't turn on ie no power is getting to it. When the borrowed power supply (with the different mA figure) from another HP printer is plugged in it then works!

We also tried swapping the kettle lead in case that was the problem but it's definitely the original power supply that has broken.

Fifer

spookylukey wrote: »

When the original power supply is plugged into the printer the printer doesn't turn on ie no power is getting to it. When the borrowed power supply (with the different mA figure) from another HP printer is plugged in it then works!

We also tried swapping the kettle lead in case that was the problem but it's definitely the original power supply that has broken.

Sorry, I misread your original post. That it works and that the difference in the current capacity figures is so small suggests that it should be fine. Just check that it doesn't get too hot after it's been on a wee while.