The EMCOTEC filter capacitor becomes plugged at a free servo connection of the receiver and eliminate voltage peaks which could interfere the receiver. Some digital servos could produce high tension peaks, which could destroy the receiver or the could crash the microcontroller in the receiver. The filter capacitors in the receivers are not enough to filter the disturbance voltage. Also the big capacities in the DPSI systems are not enough in some cases. The EMCOTEC filter capacitor protects the receiver of high tension peaks and becomes fixed easily in the model. Also temporary voltage drops become bypassed because of the capacitor. The filter capacitor is a perfect extension, which increases the security in the receiving system - with or without battery switch.