A method to generate the light radiation and switching on of the light-emitting diode of the radiation source in an optical sensor for tracking a linear textile material.

摘要

The invention relates to the method for generating the light radiation for tracking a linear textile material, wherein the source of the light radiation is a light-emitting diode (1). In the course of the generation of the light radiation, the influence of the temperature of the light emitting diode (1) on the intensity of this light radiation is eliminated, and so their constant intensity is maintained. The influence of temperature on the intensity of the light radiation is compensated for by changing the magnitude of the feed current as a function of the change in the temperature-dependent voltage at the transition PN in the transmissive direction. The invention also relates to the switching of the light emitting diode (1), wherein the anode of the light emitting diode (1) to the output of the operational amplifier (2) is connected and the cathode of the light emitting diode (1) via a series resistor (R3) to the negative pole of Input is connected, wherein the light emitting diode (1) first resistor (R1), which is switched between the anode of the light emitting diode (1) and the negative input of the operational amplifier (2), and second resistor (R2) connected between the negative input of Operational amplifier (2) and the cathode of the light emitting diode (1) is switched on, are assigned in parallel, and where the positive input of the operational amplifier (2) to the voltage (Ui) is connected to adjust the operating point of the radiation source.