Abstract: In a circuit arrangement including at least one control loop composed of a controllable oscillator for producing an a.c. output signal whose frequency is a function of the value of a control signal thereto, a frequency/d.c. signal converter connected for producing a d.c. output signal which is a function of the frequency of the oscillator output signal, and a signal comparator having two inputs and an output, with one comparator input receiving a signal corresponding in value to the converter output signal, and the oscillator receiving a control signal corresponding to the signal at the comparator output, the circuit arrangement further including an a.c. signal source, and a second frequency/d.c. signal converter connected for producing a d.c. output signal which is a function of the frequency of the a.c. signal produced by the source, with the other comparator input receiving a signal corresponding in value to the second converter output signal.

Abstract: A zero voltage switch comprises two parallel connected current branches for taking over the D.C. current from a D.C. current source in half cycles of an A.C. voltage and a third current branch for blocking the other two current branches in zero axis crossing phases of the A.C. voltage so as to produce control pulses, a logic unit being provided for controlling the D.C. current source whereby an extremely small current is provided up to the beginning of a first control pulse, an increased current is provided during the control pulses and an intermediate current is provided between the control pulses.

Abstract: A clock signal generator comprises a counter, a shift register and a logic circuit, the generator receiving a clock input signal of constant period and producing a clock output signal of which the period increases according to a geometrical ratio, within each shift cycle of the shift register.

Abstract: An input stage for an ignition control circuit is provided for producing an output signal from a comparator which switches the primary current circuit of the ignition coil in dependence on a control signal in which the control signal causes alternate switching of two current multipliers, a first charging current determined by a charging resistance and a second charging current determined by the first current multiplier charges a first capacitor, a third charging current derived from the second charging current charges a second capacitor, a first discharge current determined by a discharging resistance and a second discharge current determined by the second current multiplier discharges the first capacitor, a third discharging current derived from the second charging current discharges the second capacitor and a comparator compares the voltage at the second capacitor with a reference voltage to produce an output signal for switching the primary current of the ignition coil.

Abstract: A feedback amplifier which is constructed as a threshold value switch includes a current fed differential stage and additionally comprises two transistors whose emitters are each connected to one output of the differential stage with a first resistor connected between these two outputs and second and third resistors forming operating resistors connected between the supply voltage and the two transistors, each operating resistor being connected to the collector of one transistor and the base of the other transistor respectively.

Abstract: In an orientation arrangement during journeys in vehicles on land, means are provided for the purpose of ascertaining the distance covered by the vehicle and the changes in the direction of the vehicle. The distance covered by the vehicle and its respective location are ascertained and indicated with the aid of the distance measured and the changes in direction which have been ascertained.