Input circuit for optocouplers

摘要

An input circuit for optocouplers is provided with the invention which allows optocouplers of this type to be dimensioned in optimum fashion for data or signal transmission, virtually freely and without restriction due to noise suppression conditions. To this end an undervoltage noise detector and an overvoltage noise detector are connected to that operating voltage of the optocoupler(s) which is affected by noise. The output signals of the undervoltage noise detector and the overvoltage noise detector are combined by means of a signal combination circuit whose output is connected to the data or signal transfer input of the data or signal collection memory of the respective optocoupler in such a way that a data or signal transfer from the optocoupler by the data or signal collection memory is prevented if the noise to which the operating voltage is subjected is so severe that the signals or data at the output of the optocoupler(s) are no longer reliable.