Circuit for independent control of two loads, esp. warning lamps for remote door locking controllers for motor vehicles via cable

摘要

The circuit has a control device with two output lines, to each of which is applied a low or high level voltage to switch a load on or off. The control cable (8) is connected to the controller (6) output lines via a signal circuit (9) with which the voltage level on the control cable can be switched between three different discrete values. Each load (10,20) is driven by an input transistor (T11,T21) whose base is connected to the control cable and whose base- emitter voltage is defined by a limiting diode (Z10,Z20) connected to the control cable and with breakdown voltage higher than the mean and lower than the maximum voltage level on the control cable.