Nixdorf Computer Ag

Siemens Nixdorf Informationssysteme Aktiengesellschaft

Nisdorf Computer Ag

Werner Pollmeier

Ernst Weidner

Josef Schuck

Method of splitting a power supply

Buffered DC power supply system

Signal transmission between modules connected to a common backplane

Circuit arrangement for driving an MOS field-effect transistor

Constant-voltage supply system with several constant-voltage sources

The present invention relates to a method and apparatus for the generation of voltage pulses for controlling the switching operation in switching power supplies. A voltage increase of a pulse generator is respectively started when reaching a first, lower threshold (A). Resetting of the voltage increase is carried out in free-running mode, when the voltage increase reaches a second (D) or a third (C) threshold lying between the first (A) and the second (D) one. In sync mode, the pulse edges occurring in the synchronization signal (V.sub.sync) effect resetting of the voltage increase. The advantages of the invention lie in the fact that the switching current, occurring at the change form free-running mode to sync mode due to the frequency difference, is minimized and that the generator operates reliably.

Method and apparatus for the generation of voltage pulses

Circuit arrangement for the protection of a component, particularly a switching semiconductor, which is series connected to a voltage source via an inductor, against an overcurrent due to magnetic saturation of the inductor, a second inductor in the series circuit, which limits the overcurrent during the response time of an excess current cutoff and whose magnetizing current is roughly linear over time, at least during the unsaturated state of the first inductor, and does not exceed the maximum permissible current value for the component to be protected during the entire response time.

Switching arrangement to protect a component against overcurrent due to

A transistor switching circuit arrangement for switching at least one switching transistor on and off wherein, in order to achieve low power dissipation by delaying the change which occurs in base current to the cut-off value on conversion into the blocked state and by a subsequent brief disruptive operation of the base emitter section and in order to achieve fast switching on, there is provided a choke coil through part of which the base-emitter current of said switching transistor is fed and through part of which the current being switched is passed in positive feedback mode.

Transistor switching circuit

A circuit for the production of an output voltage generated based upon an input direct voltage and a given desired voltage. A series connection comprises a longitudinal regulating member, an inductor and a push-pull current transformer which produces the output voltage. The input direct voltage is fed to the push-pull current transformer. The push-pull current transformer includes a push-pull transformer having push-pull primary winding and a secondary winding. In addition, the push-pull current transformer includes switching transistors which are switched on and off in push-pull by a control circuit. The control circuit delivers a suitable cyclical changing control signal to the switching transistors. Circuitry is provided for minimizing if not eliminating spikes in the current occurring during a switching of the switching transistors. As a result, the switching transistors remain free from excessive voltages which can damage same.

Circuit for the production of an output voltage depending on an input

The power loss developed in a semiconductor switch during turning on the current flowing from a DC source through a main inductor is reduced by connecting in series between the switch and the main inductor the series combination of a diode and a further inductor, with the diode being poled to pass current from the switch to the main inductor. The parallel combination of a further capacitor and a further diode is connected between a tapping on said further inductor and the junction of said series combination with the semiconductor switch. To reduce the power loss during turning-off of the current, there is connected between the junction of the semiconductor switch and the inductor two paralleled series combinations of diode and capacitor with the elements in opposite order in the branches and the diodes poled in the same direction, the junctions of the capacitors and diodes in the two series combinations being connected through a series diode-inductor combination. The series combination of semiconductor switch and inductor may be one half of a push-pull inverter circuit.

Semi-conductor switching circuit with transistor switching power loss

A voltage stabilizer includes the series combination of a series regulator element and inductor and an inverter circuit connected across a direct voltage supply. The series regulator is controlled by a comparator which compares the stabilized output voltage with a reference voltage. A diode energized in the forward direction by inductive turn-off voltage appearing on the inductor is connected in shunt with the series combination of inductor and inverter circuit. A series combination of a diode energized in the forward direction by the inductive turn-off voltages appearing on the inductor and the parallel combination of a resistor and a capacitor may be connected in shunt with the input of the inverter circuit. The inverter may be of the push-pull parallel or bridge type. The inverter output may be inductively coupled with the series control element.

Voltage stabilizer

The power loss developed in a semiconductor switch during turning on the current flowing from a DC source through a main inductor is reduced by connecting in series between the switch and the main inductor the series combination of a diode and a further inductor, with the diode being poled to pass current from the switch to the main inductor. The parallel combination of a further capacitor and a further diode is connected between a tapping on said further inductor and the junction of said series combination with the semiconductor switch. To reduce the power loss during turning off the current there is connected between the junction of the semiconductor switch and the inductor two parallelled series combinations of diode and capacitor with the elements in opposite order in the branches and the diodes poled in the same direction, the junctions of the capacitors and diodes in the two series combinations being connected through a series diode-inductor combination. The series combination of semiconductor switch and inductor may be one half of a push-pull inverter circuit.

Semiconductor switching circuit with transistor switching power loss

A circuit arrangement in a line which transfers a condition by means of a semiconductor switching arrangement which produces a logic condition associated with monitored data processing equipment. The semiconductor switching arrangement has a thyristor characteristic and consists of a pair of transistors which form a control circuit with one of the transistors, particularly the emitter thereof forming the anode point of the semiconductor arrangement. This one transistor is also provided with a base-emitter resistor which is dimensioned corresponding to the sum of the collector-base residual currents of the pair of transistors in the control circuit when the semiconductor switching arrangement is in the blocked or non-conducting condition.

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Verl, Germany

Werner Pollmeier