Abstract: A cranking device for internal combustion engines includes a permanently excited cranking motor and an electrical run-down brake, having a switching device (25) which, during the run-down phase of the cranking device, connects the connecting leads of the brushes (4, 4') of the cranking motor (1) to one another via a resistor (24). An additional winding of the engaging relay (15) of the cranking device is used as the resistor.

Abstract: To test magnetic elements, by integrating output signals derived from a sensing coil to which the magnetic elements are exposed, by being passed therethrough, the output signals are additionally applied to a threshold switch, which activates the integrator only if (a) the output signals exceed a given threshold, and (b) they are in a predetermined polarity, so that the integrator will not integrate first in one and then in reverse direction, thus providing no useful output signals. The system is simple and avoids the necessity of special circuitry.

Abstract: When the starter motor which can be coupled to an internal combustion engine, typically an automotive engine, has accomplished its function and the automotive engine started, it is disconnected by a switch which is controlled from a sensing circuit connected to the energization circuit of the starter and responsive to a-c components. The system operates on the basis that, before the engine has started, the sequential compression and decompression in the cylinders of the internal combustion engine will result in alternating components which are superimposed or modulated on the energy flow to the starter motor. When the internal combustion (IC) engine has started, the undulations and variations in energy supplied to the motor will terminate. The system is sensitive to such termination and disconnects the starter motor at that time.