Abstract: The described circuit arrangement converts an alternating current signal into a binary signal when the level of the alternating current signal exceeds an initial threshold voltage. During the period of time in which the alternating current signal is delivered, the threshold voltage is reduced. If the level of the alternating current signal falls short of the reduced threshold voltage, then the delivery of the alternating current signal is interrupted and the threshold voltage is again increased to its initial value. This hysteresis during switch-on and switch-off of the binary signal results in either an error-free binary signal being supplied or no binary signal at all.

Abstract: The invention relates to a circuit for deriving output of signals and output counter cycle signals from a one-sided input signal.The circuit contains two transistors coupled to at least one current reflecting circuit. The two outputs of the current reflecting circuit are connected either with the emitters or the collectors of two transistors, whereby one connecting line at least one resistor is disposed. The interconnected bases of each of the two transistors are connected to an adjustable direct-current source. The equal electrodes of the two transistors which are not connected with the current reflection circuit form the signal output and the signal counter cycle output.

Abstract: A variable resistance device utilizes a control signal variable resistor and a first fixed resistor connected in series as a voltage divider as well as a second fixed resistor and an operational amplifier having an input connected between the first fixed resistor and one side of the variable resistor and an output connected through the second fixed resistor to the other side of the variable resistor, as a substantially linear variable resistance device where the variable resistance is obtained across the voltage divider.