Abstract: A charging voltage converter on a vehicle is equipped with an upstream circuit, which includes at least one working inductor. Furthermore, the converter has a switching unit, which is connected downstream of the upstream circuit. The working inductor connects a first input potential of an input of the voltage converter to the switching unit. A second input potential of the input is connected via a reverse current blocking device of the upstream circuit to the switching unit.

Abstract: A vehicle electrical system is equipped with a DC charging connection, a rechargeable battery, a first DC-DC converter and an electrical drive. The first DC-DC converter has a first side. This is connected to a connecting point via a first switch. The first DC-DC converter has a second side to which the electrical drive is connected. The second side is connected to the rechargeable battery via a second switch and via a connecting point or is connected to the rechargeable battery directly. The vehicle electrical system has a second DC-DC converter. This is connected to one side of the first switch.

Abstract: A vehicle electrical system is equipped with at least one high-voltage consumer, a DC charging connection a rechargeable battery, a rectifier and a changeover switch. The high-voltage consumer is connected to the rechargeable battery by the changeover switch via a first switching device in a first switching position of the changeover switch and is connected to the rechargeable battery by the changeover switch in a second switching position of the changeover switch via a second switching device, wherein the DC charging connection is connected to the rechargeable battery via the first switching device.

Abstract: A charging circuit is equipped with a storage battery terminal, a direct-current terminal and an alternating-current terminal, which is connected to an alternating-current side of a rectifier of the charging circuit. The direct-current side of the rectifier is connected via a changeover switch to a first side of a DC-to-DC converter, wherein the changeover switch connects the first side of the DC-to-DC converter either to the direct-current terminal or to a first potential of the direct-current side of the rectifier. A second potential of the direct-current side of the rectifier is connected to the direct-current terminal via a diode. The reverse direction of the diode points toward the direct-current terminal. A second side of the DC-to-DC converter is connected to the storage battery terminal, to which the direct-current terminal is connected via an isolating switch. A vehicle electrical system having the charging circuit is also described.

Abstract: The disclosure provides a vehicle electrical system equipped with a high-voltage branch and a first low-voltage branch, which is galvanically isolated from the high-voltage branch by insulation. The low-voltage branch has at least one low-voltage line, which leads to the high-voltage branch. The low-voltage branch has a voltmeter. The voltmeter is connected in a signal-transmitting manner to the at least one low-voltage line. Furthermore, the voltmeter is set up to detect whether an absolute voltage value of the at least one low-voltage line with respect to a ground potential of the vehicle electrical system lies above a voltage limit. The voltage limit defines an absolute voltage value which is greater than the absolute value of a maximum signal voltage of the low-voltage line, which the low-voltage line has during fault-free operation.

Abstract: An on-board vehicle electrical system is provided with a rechargeable battery, an AC voltage connection and a DC voltage connection. The DC voltage connection is connected directly to the rechargeable battery via a connection point. The AC voltage connection is connected to the rechargeable battery via a rectifier and a first switch via the connection point. The rectifier is connected to the rechargeable battery via a DC-isolating DC/DC converter and a second switch. The second switch is connected to the rechargeable battery via the connection point. There is at least one consumer on-board electrical system branch, which includes a Cy capacitance and which is connected to the rechargeable battery via the second switch.

Abstract: Various embodiments of the teachings herein include a charging circuit for a vehicle-side electrical energy store comprising: an alternating current terminal; at least two smoothing capacitors; a configuration device; and a rectifier connecting the alternating current terminal to the configuration device. The configuration device connects the rectifier to the smoothing capacitors, and the configuration device is programmed to connect the smoothing capacitors to one another in a first parallel connection and a second series connection. The alternating current terminal comprises a neutral conductor terminal connected to the configuration device via a diode circuit. The configuration device comprises a first switch connecting the smoothing capacitors to one another in parallel when closed. The configuration device comprises a diode connecting the smoothing capacitors to one another in series when closed.

Abstract: A configurable DC-DC converter circuit has first and second DC voltage connections. The first DC voltage connection connected to a plurality of galvanically isolating DC-DC converters via a configuration circuit that has first and second switches, between which a changeover switch connects the first and second switches to one another via a diode device and connects the first and second switches to one another via a resistor. The DC-DC converters connected to the first and second switches. In the first changeover switch position, the first and the second switch are closed in a first configuration position and connect the DC-DC converters in parallel with one another. If the changeover switch is in the first switching position, the first and second switches, in a second configuration position in which the first and the second switches are open, the DC-DC converters are connected in series with one another via the diode device.

Abstract: A method for detecting an insulation fault in a vehicle on-board electrical system having an HV and LV on-board electrical system branches. The LV branch has at least one first LV potential and a second LV potential that differs therefrom and corresponds to a ground potential of the vehicle on-board electrical system. The HV branch has positive HV negative HV potentials. These HV potentials are DC-isolated from the LV branch potentials. An insulation fault between at least one of the HV potentials and the first LV potential is detected by identifying a current flow. The current flow runs through a voltage limiting circuit connected between the ground potential and the first LV potential. This circuit connects the first LV potential, via a plurality of diodes, to a voltage limiting element connected to the ground potential of the vehicle on-board electrical system. A vehicle overvoltage protective circuit is also described.

Abstract: Various embodiments of the teachings herein include a vehicle-side charging apparatus comprising: an AC voltage connection; a rectifier connected to the AC voltage connection; a first DC/DC converter and a second DC/DC converter; and a DC voltage connection. Each DC/DC converter includes a intermediate circuit capacitor and a switch unit. The rectifier is connected to the DC voltage connection via the DC/DC converters. There is a switch connecting the DC/DC converters in a switchable manner. In a first switching state the respective intermediate circuit capacitors and the respective switch units of the DC/DC converters are connected in parallel with one another and in a second switching state in series with one another. There is a third DC/DC converter connecting the rectifier to the DC voltage connection.

Abstract: A method for discharging a vehicle high-voltage electrical system, which is galvanically isolated from a ground potential, in the presence of a residual current makes provision for the following step: determining whether a residual current flows between a first HV potential of the vehicle high-voltage electrical system and the ground potential or a residual current flows between a second HV potential of the vehicle high-voltage electrical system and the ground potential. The method furthermore makes provision to discharge only that Cy capacitance which exists between the ground potential and that HV potential from which or to which the residual current flows. The discharging is triggered by determining the existence of a residual current. Furthermore, an on-board vehicle electrical system and an insulation monitoring device which are designed for performing the method are described. In addition, a corresponding charging-station high-voltage electrical system is described.

Abstract: A method for detecting an insulation fault in a vehicle on-board electrical system having an HV on-board electrical system branch and an LV on-board electrical system branch provides for the LV on-board electrical system branch to have a positive supply potential and a negative supply potential that corresponds to a ground potential of the vehicle on-board electrical system. The HV on-board electrical system branch has a positive HV potential and a negative HV potential which are DC-isolated from the potentials of the LV on-board electrical system branch. An insulation fault between at least one of the HV potentials and a positive LV potential is detected by identifying a current flow through a voltage limiting circuit connected between the ground potential and the positive LV potential.

Abstract: A vehicle-side charging circuit includes an AC-voltage interface, a rectifier connected thereto and at least one first and one second DC-to-DC converter. The DC-to-DC converters are electrically isolating, and each have at least one intermediate circuit capacitor and at least one switch unit. The charging circuit also includes an on-board electrical system connection. The rectifier is connected to the on-board electrical system connection by way of the DC-to-DC converters. The charging circuit has a switch device which connects the DC-to-DC converters so as to be switchable between one another. In a first switching state, the switching device connects the two intermediate circuit capacitors and the switching units of the DC-to-DC converters in parallel and, in a second switching state, connects the intermediate circuit capacitors and the switch units in series.

Abstract: A vehicle charging circuit includes an AC voltage connection that has a plurality of potentials, a switch device, a plurality of rectifiers that are each in the form of a bridge rectifier, a plurality of step-up converters, and a plurality of galvanically isolating DC-DC converters. Inputs of the rectifiers are connected to one other. The interconnected inputs of the rectifiers are connected to the AC voltage connection via the switch device. The rectifiers each have an output, downstream of each of which is connected one of the step-up converters. The step-up converters are connected to a rechargeable battery connection of the vehicle charging circuit.

Abstract: A charging and heating circuit is equipped with an AC voltage connection, a DC voltage connection and a rectifier. The rectifier is connected between the AC voltage connection and the DC voltage connection. The charging and heating circuit further includes a heating resistor which is connected to the rectifier and the rectifier is thereby set up to supply the heating resistor with current. Also described is a vehicle electrical system which includes the charging and heating circuit in addition to an accumulator.

Abstract: A vehicle-based high-voltage charging circuit is provided with an AC voltage terminal, at least two galvanically isolating DC-DC converters designed as step-up converters and a rectifier via which the DC-DC converters are connected to the AC voltage terminal, and a changeover switch. The charging circuit has a first and a second DC voltage terminal selectably connected to the first DC-DC converter via the changeover switch. The charging circuit has a third DC voltage terminal connected to the second DC-DC converter, wherein the charging circuit also has a controller which is set up, in a first mode, to drive the DC-DC converters according to a first target output voltage which is at least 750 V and at most 1000 V, and, in a second mode, to drive the DC-DC converters according to a second target output voltage which is at most 480 V or at most 450 V.

Abstract: A galvanically coupling DC-to-DC converter has a first side and a second side. The first side has a first potential and a second potential. The DC-to-DC converter has a first, a second and a third transistor. The transistors are connected in a series circuit via a first and a second connecting point and are connected between the potentials of the first side. A respective load inductor is connected to the two connecting points. The load inductors are each connected between one of the connecting points and one of two potentials of the second side of the DC-to-DC converter.

Abstract: A vehicle electrical system is equipped with a DC charging connection, a rechargeable battery, a first DC-DC converter and an electrical drive. The first DC-DC converter has a first side. This is connected to a connecting point via a first switch. The first DC-DC converter has a second side to which the electrical drive is connected. The second side is connected to the rechargeable battery via a second switch and via a connecting point or is connected to the rechargeable battery directly. The vehicle electrical system has a second DC-DC converter. This is connected to one side of the first switch.

Abstract: A vehicle charging circuit includes an AC voltage connection that has a plurality of potentials, a switch device, a plurality of rectifiers that are each in the form of a bridge rectifier, a plurality of step-up converters, and a plurality of galvanically isolating DC-DC converters. Inputs of the rectifiers are connected to one other. The interconnected inputs of the rectifiers are connected to the AC voltage connection via the switch device. The rectifiers each have an output, downstream of each of which is connected one of the step-up converters. The step-up converters are connected to a rechargeable battery connection of the vehicle charging circuit.

Abstract: Various embodiments include a charging circuit for a vehicle-side electrical energy store comprising: an alternating current terminal; at least two smoothing capacitors; a configuration device; and a rectifier via which the alternating current terminal is connected to the configuration device. The configuration device connects the rectifier to the at least two smoothing capacitors and is configured to connect the smoothing capacitors to one another in a first parallel arrangement and a second series arrangement. The alternating current terminal comprises a neutral conductor terminal connected via a diode circuit to the configuration device.