A system for waking up a dormant car control device of rail car braking system that provides a sufficient wake up voltage in response to pressurization of the brake pipe of the transit car. A supercapacitor is used to output a predetermined voltage when a pressure switch responsive to a source of brake pipe pressure moves to a closed position in response to a charging of the brake system. A first circuit boosts the predetermined voltage of the supercapacitor and energized the contacts of a relay that can selectively provide the boosted voltage to an input of a car control device. A second circuit controls the relay to select when boosted voltage should be provided to the input of a car control device. A third circuit selectively provides power to the first and second circuits based on whether the car control device should receive the boosted voltage.