Lights e.g. lamps, testing method for e.g. motor vehicle trailer, involves measuring comparison current value, and testing function of lights based on comparison of value of current flowing through lights with measured value

摘要

The method involves monitoring current flowing through two lights (L1, L2) using a trailer controller (1) for actuating the lights depending on light signals of a motor vehicle. A comparison current value is measured by transmitting current pulses (I1, I2) for each light. Function of the lights is tested based on the comparison of value of current flowing through the lights with the measured comparison current value. The current is tested based on the measured comparison current value during single current impulse of lights. An independent claim is also included for a trailer controller comprising a signal input unit.