Safety sensor has processor in communication with memory, and two parallel circuits connected in series and each with switch and first resistance connected to switch in parallel

摘要

The safety sensor has a processor (12), to the inputs (14,16,18) of which are connected a first (24), second (26), and third (28) electrical conductor, with the first conductor connected to a voltage source (32), and the third to an indicator (34). Two parallel circuits (40,42) are connected in series and each includes a switch (48,58) and a first resistance (44,54) connected to the switch in parallel. One parallel circuit connects the first conductor to the second, and the other parallel circuit connects the second conductor to the third. At least one memory (30) is in data transmitting communication with the processor. Independent claims are also included for the following: (A) a trailer coupling incorporating the aforesaid safety sensor; and (B) a lorry with a trailer coupling which incorporates the aforesaid safety sensor.