Hey guys,
I am trying to create a variable current driver. Currently the voltage across two terminals is held constant at 5V, and I want to vary the resistance through it with a potentiometer. However, since the resistance needs to vary from like 3ohm-5ohm, most potentiometers cannot handle this power. I am hoping to use a power transistor instead (by varying the voltage at it's base or gate), but am having some problems. Mainly, the turn on is very exponential rather than a nice linear ramp.
Does anyone have any suggestions, other than an expensive rheostat?
Thanks,
John
I am trying to create a variable current driver. Currently the voltage across two terminals is held constant at 5V, and I want to vary the resistance through it with a potentiometer. However, since the resistance needs to vary from like 3ohm-5ohm, most potentiometers cannot handle this power. I am hoping to use a power transistor instead (by varying the voltage at it's base or gate), but am having some problems. Mainly, the turn on is very exponential rather than a nice linear ramp.
Does anyone have any suggestions, other than an expensive rheostat?
Thanks,
John