Vdo Adolf Schindling Ag

Quarz-zeit Ag

Manfred Stein

Dieter K Busch

Martin Haub

Wolfgang Schuller

Electric clock with an oscillator, particularly a quartz oscillator, a frequency divider connected to the quartz oscillator and a control stage connected following the frequency divider, via which control stage a stepping motor, which stepping motor is coupled with the dial train, is able to be applied with pulses of the same or alternating polarity. Each pulse is formed from a number of individual pulses, the pulse duty cycle of the individual pulses reducing toward the end of the first mentioned pulses.

Pulse control for an electric clock

An electronic clock, particularly a quartz clock, with a timer signal transmitting stage, an indicator system which at least contains a minute counter and an hour counter, as well as a decoding stage and a digital indicator board, and an alarm system which at least contains a presettable counter associated with the minutes and a presettable counter associated with the hours, the outputs of which presettable counters are able to be locked on the indicator system, and a coincidence stage for comparison of the output signals of the counters of the indicator system with those of the alarm system. Each counter of the alarm system constitutes a forward-rearward-counter, and switches are provided for selection of the counting direction.

Electronic clock, particularly a quartz clock

A protection circuit for a voltage regulator in integrated construction, particularly for motor vehicles, comprising a resistor in the ground connection line of the voltage regulator and a diode path between the voltage regulator-sided end of the same and the input of the voltage regulator and a unit for limiting the potential difference occurring on the resistor to a constant or a very small value in comparison to the output voltage.

Protection circuit for a voltage regulator

A method and system for testing the accuracy of the oscillators of electronic clocks includes transforming a frequency signal corresponding to the output of a clock oscillator into a non-sinusoidal signal having the same frequency as the frequency signal and filtering the non-sinusoidal signal to pass a component of the non-sinusoidal signal having a frequency associated with a reference frequency to be compared with the signal passed by the filter such that clock oscillators operating at various frequencies of which the reference frequency is an integral multiple can be tested since the non-sinusoidal signal, which is preferably a sawtooth signal, contains harmonic components corresponding to the reference frequency.

Method and system for testing the accuracy of an electronic clock

A circuit arrangement for the control of a forward-rearward-counter with at least one manually actuatable switch over which the reversing input of the counter can be triggered with different potential and the count input with count pulses. A first anticoincidence member has two inputs connected with one another over a resistor, one input being triggered via the switch. A second anticoincidence member has two inputs, one of which is in connection with the count input of the counter and with the output of the first anticoincidence member. The output of the second anticoincidence member is connected to the reversing input of the counter. Both anticoincidence members are applied with count pulses at their free inputs.

Circuit arrangement for the control of a forward-rearward-counter

An electronic clock, such as a quartz-crystal clock, is tested and may be adjusted by measuring the oscillation frequency of the clock with an active antenna. The oscillation frequency is electrically compared with a reference frequency to determine deviation and provide an output indication. Internal calibration is carried out when the system is not being used for testing.

Method and apparatus for testing the accuracy of an electronic clock

The invention relates to a wind direction indicator for sailboats wherein a rotatably mounted permanent magnet connected to the shaft of a weather vane is employed as a pick-up. By means of its magnetic field, it controls, in dependency upon the wind direction with great respect to the midship line two magnetically controllable semiconductors mutually displaced by an angle of 90.degree.. This is an improvement over U.S. Pat. No. 3,791,211.

Growing community of inventors

Eschborn, Germany

Manfred Stein