Human collaborative robots, which share their workspace with humans, have to fulfill many requirements. This paper shows a way how to combine the requirements of first stopping and subsequent backdrivability in the case of power outage. In particular, a circuit with supercapacitors is designed and implemented that powers an adjustable torque limiter in the case of power loss for a short time to achieve the stop function. After the supercapacitors are depleted, the system is backdrivable. The circuit with the supercapacitors is small enough to be implemented close to the actuator. Tests with varying mass and varying speed are conducted to test the limits of the system when being used without an additional power off brake. The results show that the system is feasible, and also shows the current limitations of the system in regard to brake displacement and brake time.