modified 9 years ago

font 5 volts

00:45:27

font dc

published 9 years ago

justinmh

9 years ago

So just for this to run and have a 5 volt output with no load you are producing a lot of waste heat... how much? Well if we use the formula for a voltage reg, it is (v_in-v_out)i_total. So (20-5)1-25=15*1.25=18.75 watts of waste heat.

BillyT

9 years ago

@justinmh your calculations are correct, it's just the no load statement I am having trouble with, to have 1.25 A current there is got to be the 4 Ohm load as shown. There is still the 18.75W wasted power for the 6.25W output. The only way around this is a switch mode power supply, any ideas any one?

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