Circuit for shaping a measurement-signal voltage into a square- wave signal

摘要

To derive a stable square-wave signal from a measurement- signal voltage obtained from a voltage divider and containing a DC component and an AC component, the low end of the voltage divider is grounded through a load resistor shunted by the series combination of a resistor and a grounded capacitor. The low end is connected through the resistor to the negative input of a comparator and through an additional resistor to the positive input of the comparator. This positive input is also connected through a feedback resistor to the output of the comparator. The low end is connected to the supply voltage (U.sub.V) via a second voltage divider whose first resistor is formed by a controllable, temperature-stabilized zener diode connected to the supply voltage (U. sub.V) through the second resistor of the second voltage divider. The measurement-signal voltage (U. sub.M) obtained from the tap of the first voltage divider is applied to the control electrode of the zener diode.