Now let’s do a sample calculation. Let’s use the camera that requires 12 VDC and uses 10 watts. We determined that it requires 0.833 amps. Using Ohm’s law we can calculate the resistance of a camera. R = V / I R = 12 VDC / 0.833 amps = 14.4 ohms. So this means R2 in ou...
VoltageV=I×R=P/I= √(P×R) in volts V CurrentI=V/R=P/V= √(P/R) in amperes A ResistanceR=V/I=P/I2=V2/Pin ohms Ω PowerP=V×I= R ×I2=V2/Rin watts W See also:The Formula Wheel of Acoustics (Audio) The BigPower Formulas ...