Method for reduction of switching time of opto-coupler utilized as e.g. reflex light barrier in open construction to transmit signals in digital applications, involves attaching emitter of photo-transistor at negative operating voltage

摘要

The method involves integrating an opto-coupler (2) with a LED (3) in a circuit arrangement (1) and an output (8). The arrangement comprises a capacitor (13) and a transistor (11) with an emitter (E), base (B) and a collector (C). A collector of a photo-transistor (4) is attached at the emitter of the transistor, where an output signal at the output is coupled to the base of the transistor. The collector of the transistor is attached at positive operating voltage (9), and the emitter of the photo-transistor is attached at negative operating voltage (10) via an operating resistor (5). The transistor is designed as an npn-or pnp-transistor and FET. An independent claim is also included for a circuit arrangement for reduction of the switching time of the opto-coupler.