Circuit isolator for signal transmission galvanically separating input circuit from output circuit, has receiver of opto-coupler arranged between reference input and collector connection of second regulatable Zener diode

摘要

The input circuit has first regulatable Zener diode (u3) with transmitter connected optocoupler in series having reference input (1b) wired with voltage proportional to input signal of circuit isolator. A second regulatable Zener diode (u2) is connected parallel to the transmitter (d1) and to first regulatable Zener diode. The two Zener diodes have identical temperature response curve. A voltage divider (r6,r3,r2) included taps supply current of transmitter at first point (r3) and is connected at second point as reference input (17) for second regulatable Zener diode (u2). Regulatable resistance (r5) is arranged between the second point (15) and the reference input of the second regulatable Zener diode (u2).