Power supply for Waeco Console Cooler
Submitted: Wednesday, Mar 12, 2003 at 10:07
ThreadID:
3793
Views:
2540
Replies:
4
FollowUps:
6
This Thread has been Archived
Member - Mal
Dear all,
I have a Waeco Console Cooler which nominally _Affordable_Storage_Drawers.aspx 32 watts at 12 volts. I want to be able to run it off 240 volts from time to time.
I also have an old "Fridgemate" power supply and the specifications state: Input of 100 to 270 volts AC, output of 27 volts DC (which measures 29.3 volts with a multimeter) at 1.5 amps and 40 watts continuous. 55 watts intermittent at 2 amps.
The question: What do I have to do to the Power Supply to have it sucessfully run the Waeco Cooler from 240 volts?
I imagine it's a resistor of "X" ohms in series with the positive lead.
Also could you please tell me how you arrived at the solution in terms of Ohm"s Law or whatever.
Thanks for your asistance.
Mal T.
Reply By: GaryInOz - Wednesday, Mar 12, 2003 at 18:15
Wednesday, Mar 12, 2003 at 18:15
In answer to your original question, the Fridgemate power supply is of no use for your cooler The 24V would blow the s**t out of the Waeco (fan + pielter effect device/compressor), another problem would be the current draw of the Waeco ~3 amps (FYI 12 volts/32 watts) exceding the intermittent capacity of the power supply (2 amps intermittent).
In short, you would not expect a 12 volt globe to last if you connected it to 24-29 volts would you? If you did put a resistor in the circuit you would cut down the voltage, but you would still NOT be able to supply the 3 amps needed by the Waeco. This resistor would also dissipate about half the energy the power supply provides as heat. It's just not worth the hassle!
A good solution would be to buy a cheap car battery charger (12 volt, 5 amp) with a small SLA (12 volt, 7-10 Ah) battery hooked across it to stablise the voltage into the Waeco. This would also provide a backup for short excursions away from power (picnics, etc) without allowing the cooler to get warm, therefore minimising any possibility of food spoiling. The SLA battery could also be charged throu a spare cigarette lighter outlet. DO NOT use the battery charger alone to power the Waeco!!
Volts = amps x ohms, or
Ohms = volts/amps, or
Amps = volts/ohms.
Power (watts) = volts x amps
AnswerID:
14978
Follow Up By: Member - Mal - Thursday, Mar 13, 2003 at 10:10
Thursday, Mar 13, 2003 at 10:10
GaryInOz,
Thank you very much for your reply. My rusty high school Physics of 40 years ago made me suspect that, thus the question for confirmation. I already have the charger and battery so that is the way I'll go. By the way, those 12v/7Ah SLA batteries are $25 at Oatley electronics, and $50 at Dick Smiths. Thanks again,
Mal T.
FollowupID:
9120
Reply By: Bob Y. - Wednesday, Mar 12, 2003 at 22:29
Wednesday, Mar 12, 2003 at 22:29
Mal, Jaycar and Dick Smith have power supplies, 240v AC - 12v or 13.8v DC, of varying types. From about 4 amps up to 15 amps. They will do the job you require, but at a price.
We've got one of those Fridgemate chargers, and the fridge, gathering dust. Suppose the fridge would make a good pot plant holder!
Those Peltier effect fridges often work better than people give them credit for, but they like heaps of power. Had a Koolatron about 20 years ago, and it even froze the carrots, when the fridge wasn't opened for a couple of days. Hooroo...
AnswerID:
15012
Follow Up By: Member - Mal - Thursday, Mar 13, 2003 at 10:28
Thursday, Mar 13, 2003 at 10:28
Bob,
Yes I priced one at Jaycar. Cost more than the fridge.
I turned my Fridge Mate base into an "esky" by having an aluminium lid fabricated by making a "tray" with 50mm sides and gluing a sheet of polystyrene inside it. I then pop rivetted lugs om the side of the lid so the catches on the base could hold the lid on tightly. It's a great esky because it is quiet squat and the insulation is as good as Evacool's. If you don't want it I'll buy it from you. Thanks for the reply and.............
Hoorootoutoo.
Mal T.
FollowupID:
9123