An electro-technical device includes a circuit including a coil connected to a voltage source for receiving a predetermined current therefrom and connected to an output device. The circuit includes a breakable junction and a photodiode for receiving a light signal from a fiber optic cable. The photodiode receives a light signal from a sensor. A permanent magnet includes a pole end opposing a common pole end of the coil, wherein when the coil receives an increased current from the photodiode, the coil creates an magnetic flux that repels against the common pole of the permanent magnet in order to cause the breakable junction to break and disrupt a connection between the voltage source and the output device.