Mini Fridge and Truck 12V Didn't play nice

Thread Starter

Ashley Mosey

Joined Sep 7, 2018
5
So here's the story,
I decided to invest in a mini fridge for my truck at work, I got one from a friend cheap. so i take it to work plug into the 12v Power supply (Not The 24 i promise) and the fans spin for a couple of seconds then cut out after about 30 seconds of me trying the switch to see if id knock it off its starts smoking and making spitting sounds so i unplugged it, after getting it home I take it apart and find no burns or blown components to the PCB but it doesn't work, so my plan is to buy some new components to replace the internals, stuff i seen on a few guides on people building there own mini fridges.

My question is, is there something different with a Trucks 12v supply and is there something i could do to protect the new components to stop it going up in smokes again maybe some sort of capacitor on the 12v line to smooth it out ? if so what kind? what capacitance would you suggest?
Also, I did try the mini fridge on my car 12v and it worked fine on the drive to work

Also, my electronics skill is limited to a hobbyist level I know enough to get me by but I won't be building the terminators to kill us all any time soon

Anyways Thanks in advance and any help would be much appreciated
 

Dodgydave

Joined Jun 22, 2012
8,466
If you want to run a 12V fridge on 24V, you need a DC/DC inverter, or run it across one battery. The item inside is a Peltier designed for 12V.
 

Thread Starter

Ashley Mosey

Joined Sep 7, 2018
5
If you want to run a 12V fridge on 24V, you need a DC/DC inverter, or run it across one battery. The item inside is a Peltier designed for 12V.
Thanks for your reply and yes I'm aware I can't run a 12v Peltier in a 24v socket I was using the mini fridge in a 12v socket I was simply stating that I did not use the 24v socket in the truck to avoid any confusion but this issue I had was while using the 12v socket in my car it worked fine but when I used the 12v socket in the truck it went pop there should be no difference, unless there something I'm missing like the smoothness of the 12v dc supply having an effect
 

AlbertHall

Joined Jun 4, 2014
8,505
It may just be a coincidence that it popped in the truck.
Did you check that the truck 12V actually has 12V on it and not 24V?
 

Thread Starter

Ashley Mosey

Joined Sep 7, 2018
5
It may just be a coincidence that it popped in the truck.
Did you check that the truck 12V actually has 12V on it and not 24V?
It could well be true that it's a coincidence and I can't see the 12v socket being 24v as it's marked 12v and I use my phone charger in it and the two 24v sockets my truck has are in a different location and also have different size sockets also I thought I'd check here first I don't want to go plug a fixed mini fridge in to my truck for it to just blow again strange thing is when I stripped it down to take a look at the circuitry I couldn't see any visibly blow or chard components even through I herd it pop and had magic smoke come out
 

MrSoftware

Joined Oct 29, 2013
1,575
Any time you have a bunch of unknowns, it's good to start knocking as many as you can off the list. Right now the 12v socket is assumed to be 12v, but since the fridge went pop it's kind of an unknown. 10 seconds will a multi meter will knock it off the unknown list and let you move on to the next unknown. :)
 

Thread Starter

Ashley Mosey

Joined Sep 7, 2018
5
I used other 12v appliance in the same socket in my truck though like, for example, a satnav and phone charger and they haven't pop or been damaged so on that knowledge I would think its definitely 12v I don't have a working multimeter right now i have one on order but i will double check when i receive it
 

LesJones

Joined Jan 8, 2017
2,342
I wonder if it is (Or was.) a linear regulator that was overloaded by the fridge and the pass transistor has failed short circuit so that it is now giving 24 volts output.

Les.
 
Doesn't 24 volts usually come from batteries in series? I would imagine the 12 volts probably comes from a tap between the batteries. Did you use big enough wire to run the fridge? I haven't messed with fridges too much other than replacing them, but I do know if you run a portable air compressor with too long of too small extension cord they do strange things.
 
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