A current controller for a device is provided. The current controller
includes power and ground inputs for connecting to a source of
energization, and power and ground outputs for connecting to the device.
A variable impedance is coupled in series between the power input and the
power output and has an impedance control input. The impedance control
input controls the variable impedance between a high impedance, OFF state
and a low impedance, ON state. An impedance control circuit is coupled to
the impedance control input, which biases the variable impedance in the
high impedance, OFF state when at least one of the following conditions
occur: the resistance between the power and ground outputs is less than a
threshold resistance, and current drawn by the current controller through
the power input exceeds a threshold current level.