Abstract: A measuring arrangement for testing a plurality of light waveguides by an optical measuring device having an optical measuring input to which each light waveguide can be successively coupled via an optical selector is provided. The measuring device (4,5,6) and the selector (11) are integrated parts of a uniform testing device (1), so that the arrangement can be handled in a reliable and simple manner without imposing strict requirements on care of operation.

Abstract: A pair of relay contacts directly connect the electromotor to a battery when closed. One side of the relay coil controlling the contacts is connected to a battery when a thermostat responsive to engine temperature closes. The other side of the relay coil is connected to the battery through an electronic switch, in one embodiment a thyristor, in the other a transistor, which are in the conductive state when the ignition switch is closed. The thyristor further is conductive for one operation following opening of the ignition switch, while the transistor is conductive for a predetermined time period following opening of the ignition switch.