12V 4amp pwr supply

[trickyrick]

Good day
I have on of those Colman coolers the pwr supply is not working. The
pwr supply is rated at 12 volts 4 amp. I tried to use a pwr supply
from an old laptop that was rated at 12 volts and 4.5 amps but it got
very hot in about 45 mins Whats the difference ?
Rick

 

[petrus bitbyter]

"trickyrick" <rickj@sympatico.ca> schreef in bericht
news:08e4c12c-6267-4c39-9b71-dbeaba7b123a@l31g2000vbp.googlegroups.com...

Good day
I have on of those Colman coolers the pwr supply is not working. The
pwr supply is rated at 12 volts 4 amp. I tried to use a pwr supply
from an old laptop that was rated at 12 volts and 4.5 amps but it got
very hot in about 45 mins Whats the difference ?
Rick

Suppose the power supply is getting hot. Looks like it is overloaded which
may be caused by a defective cooler. The original supply can be fried be the
same cause.

petrus bitbyter

 

[Michael Black]

On Tue, 22 Sep 2009, trickyrick wrote:

Good day
I have on of those Colman coolers the pwr supply is not working. The
pwr supply is rated at 12 volts 4 amp. I tried to use a pwr supply
from an old laptop that was rated at 12 volts and 4.5 amps but it got
very hot in about 45 mins Whats the difference ?
Rick

I'm assuming the cooler draws a constant current, though that may

be a false assumption.

The laptop supply has to be big enough to supply current when the
hard drive in the laptop starts up, and there are likely other things
that demand higher current for shorter periods. In other words, I suspect
the laptop power supply isn't designed to supply full current on a
constant basis, so when you hooked it up to the cooler, you're demanding
too much from it.

Michael

 

[trickyrick]

On Sep 23, 12:25 pm, Michael Black <et...@ncf.ca> wrote:

On Tue, 22 Sep 2009, trickyrick wrote:
Good day
I have on of those Colman coolers the pwr supply is not working.  The
pwr supply is rated at 12 volts 4 amp. I tried to use a pwr supply
from an old laptop that was rated at 12 volts and 4.5 amps but it got
very hot in about 45 mins  Whats the difference ?
Rick

I'm assuming the cooler draws a constant current, though that may
be a false assumption.

The laptop supply has to be big enough to supply current when the
hard drive in the laptop starts up, and there are likely other things
that demand higher current for shorter periods.  In other words, I suspect
the laptop power supply isn't designed to supply full current on a
constant basis, so when you hooked it up to the cooler, you're demanding
too much from it.

    Michael

Thanks Michael
That makes sence I know there is nothing wrong with the cooler My Dad
has the same one and I have being using his pwr supply for a few
weeks. So I would think that If I purchase a laptop pwr supply thats
5 amps that should do it. I ask because the laptop pwr supplys are
alot cheaper then the ones for the colman cooler