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Thread ID: 105611 2009-12-08 07:47:00 laptop power supplies newbee (10498) Press F1
Post ID Timestamp Content User
837663 2009-12-08 07:47:00 last week my son used my compaq charger on his acer laptop (for a full charge )
and now his is very slow to do anything
my charger is input (100-240v -1.7 a) an output (18.5v 1.7amp)
and his is (100-240v 1.5) and output (19v 3.42amp)
will this differance stuffed his laptop
newbee (10498)
837664 2009-12-08 10:46:00 I don't think so, if anything it would have damaged your charger as it would have been under a much higher load than it is rated for. 3.42A instead of just 1.7A. CYaBro (73)
837665 2009-12-08 11:34:00 Well you shouldn't mix adaptors up but 18.5v and 19v are so close I can't see it making much difference...

As CYaBro says, its more likely to damage the charger trying to pull 3.4Amps from one that can only supply 1.7A

However it's also possible that overloading the charger caused the output to go out of spec and caused damage somewhere.

Perhaps it's coincidence, and he managed to get a virus or a buggy program at the same time


But define what you mean by "his is very slow to do anything"
Agent_24 (57)
837666 2009-12-09 09:44:00 It's not a problem. All these chargers are switch mode regulated.

The output rating relates to the charger not the computer/battery. It just means the lower rated charger will take twice as long to fully charge the battery.
linw (53)
837667 2009-12-09 11:16:00 Unless the PSU employs current limiting circuitry you will have a problem (and we have no idea if this is the case)

Linear, Switchmode or anything else - It doesn't matter what kind of power supply you have, if you try to draw more current than it can supply you can damage it or in the case of a well designed PSU you will cause it to shutdown.

Go and take some old 200 watt PSU (preferably something really crappy like a Hyena) out of that P3 you got under your bed. Now hook it up to your new i7 gaming machine. Which do you think will happen?

A) the machine runs but very slowly
B) the PSU goes up in flames and probably takes half your system with it.
C) you are lucky and the OCP kicks in, and shuts the PSU down before any damage happens.
Agent_24 (57)
837668 2009-12-09 22:24:00 Most likely 'C' as they are designed to current limit. No real luck involved.

Current limiting doesn't have to shut the PSU down. It only has to keep the wattage to the appropriate limit. While reducing current causes computers to stop, in a charger it just means the charge takes longer.
linw (53)
837669 2009-12-09 23:26:00 Sure in the case of the laptop you may get a slower charge and no problems. But remember this is not just charging a battery, it's also powering the laptop. And like I said before, that needs what it needs, you can't just give it less current and expect it to run slower.


As for the example with the Hyena "B" is not unlikely:

www.jonnyguru.com (Allied\Deer\Hyena\Solytec all the same thing: really shitty PSUs)

Now you can't tell me that's the OCP working ;)
Agent_24 (57)
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