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portable fridge

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Thunderchild

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I've just bought one of those small camping/"lazy fat footballer fan can't be bothered to go to the fridge" mini fridges, it will run on 12 volts or off the mains with a built in SMPS (yes had the back off it already)

now on 12 volts it uses 45 W but running on the mains it uses 64 W !!! over 30% more, surely this cannot account for loses in the SMPS ? or maybe it can ? the SMPS outputs 12 volts so its not running the peltier cell at a higher voltage from the mains...

at present I have plans to change the noisy little fan (8 cm) for a nice 12 cm fan keep it cooler and QUIETER
 
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Hero999

Banned
Yes, it probably uses a cheap Chinese SMPS which is only 70% efficient.

A full sized fridge uses less power than your little fridge, it's not very efficient.
 

Thunderchild

New Member
well its a camping job so i'll have to make do, as is i'm going to dump the old and knackered 8 cm fan and replace it for a 12 cm fan striaght onto the heatsink, having thermostatic control would be nice as that way it could save power when it is not as hot
 

RCinFLA

Well-Known Member
Are you basing this on watts or VA?

Sound like VA. The power supply probably has a power factor of about 0.6 so watts will be 0.6 VA with a some addition regulator loss in the power supply.
 

Thunderchild

New Member
well it just says watts and if you think of it as a 65-70 % efficient SMPS then that adds up, anyhow i will run it on a 12 V leasure battery
 

Hero999

Banned
I have a cooler box, it's rated at 65W 230VAC and 48W 12VDC, a whopping 73.8% efficient, like I said the SMPs is cheap Chinese crap.
 

mneary

New Member
Are these your measurements, or are they values taken from the name plate? There could be a de-rating factor regarding what can be written on the name plate.

The 12V input might not be bound by the same consumer protection rules?
 
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