Flashing indicator system for road vehicles - uses resistors and differential amplifier for operation with zero or infinite initial load

摘要

The winking indicator circuit is used in a road vehicle. It has an electromagnetic relay controlled by a transistor in series with the coil of the relay. The winker is of the type which operates when the load applied to it passes from an infinite value to a determined value. The winker has a circuit consisting of resistances (20, 24, 23) and a differential amplifier (22) arranged so that the winker operates when the applied load passes from a non zero value to the determined value. This ensures the indicator circuit can operate for both conditions of operation.