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Post Info TOPIC: For all the sparkys
deverall11


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For all the sparkys
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I have a question regarding power drain.

If you plug a device in a 240v socket and the output is 12v 10 Watts, what is the power used in amps. Do you simply divide the end wattage by the original voltage (240)?

Larry



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Plendo


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HI Larry, the age old formula applies. Watts = Volts * Amps, so the output is 10 watts = 12 volts * 0.83 Amps.  It would be reasonable to assume that a 240v to 12v power supply would be about 80% efficient thus your input would be about 12.5 Watts ((10/80)*100), thus your input current would be about 0.052 Amps (12.5/240).

I hope this helps.



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oldtrack123


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Hi

As Plendo has said the POWER used will be around 1O to 20% higher due to the conversion losses in the converter .

BUT the actual AMPs drawn could be up to 50% more. as most converters have a poor power factor, often given as PF 0.xxsmilebiggrin



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deverall11


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Thanks to all that replied. Larry

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D and D


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This would have to be the shortest electrical related thread on the forum I reckon.

Dave

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KFT


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Don't jinx us please Dave

Frank

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mjt57


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Yep, the last thing that you want is a short in an electrical thread...


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Bruce and Bev


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Oh Martin - what a bright spark you are with your "short" comment LOL !!

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