hello.
i have a unit powered by a 12volt .5amp power supply that has a 3 position switch (off/low/high) rated 125VDC / 0.5A i would like to replace with something that worked like a house lighting dimmer switch. (off/variable power) it was suggested i use a potentiometer. the one i installed was rated 500VDC / .5W / 1Megaohm. it provided no power until the last 10 degrees then started smoking and burning.
where did i go wrong?
i checked the equations to determine the Watts and Ohms of the power supply ( I=V/R & P=VI ) and came up with the following rating for the power supply:
if I = .5A and V = 12V then P = 6 Watts and R = 24 ohms
everything seemed within range of the potentiometer except the Watts.
is this what burned it out? and if so, what is the rating for the one i need or can i use another and incorporated an in line resistor or something.
thanks in advance.
jeramie
i have a unit powered by a 12volt .5amp power supply that has a 3 position switch (off/low/high) rated 125VDC / 0.5A i would like to replace with something that worked like a house lighting dimmer switch. (off/variable power) it was suggested i use a potentiometer. the one i installed was rated 500VDC / .5W / 1Megaohm. it provided no power until the last 10 degrees then started smoking and burning.
where did i go wrong?
i checked the equations to determine the Watts and Ohms of the power supply ( I=V/R & P=VI ) and came up with the following rating for the power supply:
if I = .5A and V = 12V then P = 6 Watts and R = 24 ohms
everything seemed within range of the potentiometer except the Watts.
is this what burned it out? and if so, what is the rating for the one i need or can i use another and incorporated an in line resistor or something.
thanks in advance.
jeramie