Abstract: The present technology concerns a method and an arrangement for the detection of a coil in an electronic circuit, which is operated with a direct voltage lying within a prescribed voltage range, and in which the coil together with a condenser forms an electrical oscillating circuit.

Abstract: The invention relates to a device for time-controlled self-destruction of a projectile by means of a batteryless, electronic self-destruct device. Several capacitors charged by a piezo element or a surge generator during firing are used in the flight phase for operational purposes. At least two of the capacitors arc connected to the input of a comparator, so that the influence of a constantly modifiable operational voltage and the influence of a discharge of modifiable voltage levels by the piezo element or surge generator does not affect the time function.

Abstract: The inventive radar rangefinder has a transmitting/receiving antenna (22) for surveying a danger area. Said antenna is located in a radome housing (12), on a rotatable platform (18). A reflector is placed at a known distance in order to calibrate the device. This reflector is formed by an auxiliary antenna (24) with a connected delay line (26) inside the randome housing (12). The length of the virtual distance of the reflector produced then corresponds to the velocity factor of the delay line used.