I am repairing a 20A 12V power supply ,I intend to test it for 100% full load by using resistors, can anyone help to calculate in terms of the quantity ,power rating,ohm value of the resistor?thanks!!
get a car headlight bulb. or 2. VIR 12/20 .6 ohm p I^2 r 240 watts MIKE
12V/20A 0.6 ohms, and 12V*20A 240W Digikey # FVE300-1.2-ND is a 300W, 1.2 ohm, one alone gives you a half-power load, 2 in parallel would be full load, each is about $26
The power dissipation capability of your load has to be 12V * 20A 240W The load resistance has to be 12V / 20A 0.6 Ohm. So to build a load bank that can stand a 100% load for an hour you have to use a parallel circuit of power resistors mounted on a aluminum chassis actively cooled by a fan. As an example use a parallel array of 20 power resistors 12 Ohms and at least 12W each use a cooling fan operated by the same 12V that blows air across the array of resistors and the chassis holding them.
