Robert Boschgmbh

Ralf-Peter Bergmann

Stefan Koch

Jian Tian

Stephan Mueller

Stephan Binhack

Eric Hueckel

Florian Lieblang

Tobias Pristl

Michael Zeller

Ralf Bochat

The invention relates to a voltage converter () for a motor vehicle. Said voltage converter () comprises a transformer () and a power output stage (). The power output stage () comprises at least two semiconductor switches () that are connected to the transformer (), in particular to a primary winding () of said transformer (). The voltage converter () has a driver stage () which is connected, on the output side, to a control connection of the semiconductor switch () and which is designed to actuate said semiconductor switch () using a control signal (), for the purpose of generating an alternating voltage. According to the invention, the driver stage () is connected, on the input side, to a pulse signal generator () and an input capacitor (). The pulse signal generator () is designed to generate a pulse signal () and to actuate the driver stage () using the pulse signal () in order to generate the control signal (). For at least one incipient half-wave of the alternating voltage, the pulse signal () has at least one prepulse and one main pulse that generates the half-wave, the prepulse being designed to preload the input capacitor () of the driver stage () such that complete switching of the semiconductor switch () can occur more quickly than it could without a prepulse.

Voltage converter for a motor vehicle

The invention relates to an activation apparatus () for a galvanically decoupled direct voltage converter having a synchronous rectifier, comprising a signal generating device (), which is designed to generate control signals () for switch devices of the synchronous rectifier and a reference current signal (), a first comparator device (), which is coupled to the signal generating device (), and which is designed to detect the secondary-side output current (Jo) of the synchronous rectifier, compare it to the reference current signal () and generate a current control signal in dependence on the comparison, and a pulse width modulation device (), which is coupled to the signal generating device () and the first comparator device () and which is designed to generate pulse width modulated activation signals () for the switch devices of the synchronous rectifier on the basis of the control signals () and the current control signal, wherein the signal generating device () is furthermore designed to reduce the reference current signal () within a first predetermined timespan to a predetermined reference current threshold.

Activation apparatus and method for activating a direct voltage converter

The invention relates to a control unit for a motor vehicle. Said control unit comprises a voltage converter which has an inlet for a direct voltage network. Said voltage converter is designed to generate a direct voltage smaller than an input voltage on the inlet for the direct voltage network and the direct voltage is emitted on the outlet side. According to the invention, the voltage converter comprises an inverter and a transformer which is connected to said inverter. Said voltage converter also comprises an inlet for a discharge signal and is designed to discharge by means of the inverter an intermediate circuit capacitor which is connected to the inlet of the direct voltage network in accordance with the discharge signal, and to reduce a working frequency of the inverter, in particular, compared to the frequency with no discharge signal.

Control unit for a motor vehicle

A DC-DC converter including a transformer having a primary-side winding and a secondary-side winding with a center tap, and a storage choke. A rectifier circuit is connected to each of the taps at the ends of the secondary-side winding and generates a rectified output voltage at a second output of said DC-DC converter. A snubber circuit is switched via the rectifier circuit and stores energy occurring in said rectifier circuit. (An actuation apparatus includes a switching time determining device designed to determine a time interval as a function of the output voltage, the charge stored in the snubber circuit and the current fluctuations of the current through the storage choke occurring as a result of the rectification. A storage signal generator generates an actuation signal for discharging the snubber circuit as a function of the determined time interval.

Growing community of inventors

Sasbach, Germany

Ralf-Peter Bergmann