Abstract: A monitoring circuit (2) for an interlock system (1), said interlock system comprising a first monitoring line (3), a second monitoring line (4), and at least one line bridge (5), by means of which the monitoring lines (3, 4) are electrically conductively connected in a closed state of the interlock system (1), said monitoring circuit comprising a signal generation device (11) which is configured for generating a monitoring signal for the first monitoring line (3) which alternates between a first monitoring voltage and a second monitoring voltage and which is referenced to a reference potential, and a signal evaluation device (17) by means of which a voltage profile (43, 48 to 51) which is referenced to the reference potential is detectable on the second monitoring line (4), wherein the signal evaluation device (17) is configured for determining a fault on one of the monitoring lines (3, 4) which is caused by a fault voltage referenced to the reference potential, and/or a fault in the monitoring circuit (2) b

Abstract: In a control device for discharging a DC link capacitor by means of a discharging device including a load resistor and a switch element connected in series with the load resistor, the control device includes a generator unit, which is configured to generate a pulse width-modulated actuation signal for the switch element with an ascertained duty cycle, and a control unit, which is configured to ascertain the duty cycle in such a way that, in the time average, a desired discharge current flows through the load resistor.

Abstract: A device discharges an intermediate circuit capacitor. The device includes a power converter for supplying electricity to an electrical machine powering a vehicle, having the intermediate circuit capacitor and a discharge device with a series circuit of a controllable switching element and a load resistor, and a high-voltage battery feeding the power converter on the input side. The power converter has a control equipment to control the switching element, depending on a signal state at an input of the control equipment, to perform a fixed predefined number of switching operations, in which the switching element conducts, with a fixed predefined duration and a fixed predefined delay between two successive switching operations. The load resistor and its heat transfer to the power converter are set so that the load resistor is not damaged if a maximum constant voltage of the high-voltage battery is applied during a respective switching operation.

Abstract: A monitoring circuit (2) for an interlock system (1), said interlock system comprising a first monitoring line (3), a second monitoring line (4), and at least one line bridge (5), by means of which the monitoring lines (3, 4) are electrically conductively connected in a closed state of the interlock system (1), said monitoring circuit comprising a signal generation device (11) which is configured for generating a monitoring signal for the first monitoring line (3) which alternates between a first monitoring voltage and a second monitoring voltage and which is referenced to a reference potential, and a signal evaluation device (17) by means of which a voltage profile (43, 48 to 51) which is referenced to the reference potential is detectable on the second monitoring line (4), wherein the signal evaluation device (17) is configured for determining a fault on one of the monitoring lines (3, 4) which is caused by a fault voltage referenced to the reference potential, and/or a fault in the monitoring circuit (2) b

Abstract: In a control device for discharging a DC link capacitor by means of a discharging device including a load resistor and a switch element connected in series with the load resistor, the control device includes a generator unit, which is configured to generate a pulse width-modulated actuation signal for the switch element with an ascertained duty cycle, and a control unit, which is configured to ascertain the duty cycle in such a way that, in the time average, a desired discharge current flows through the load resistor.

Abstract: A device discharges an intermediate circuit capacitor. The device includes a power converter for supplying electricity to an electrical machine powering a vehicle, having the intermediate circuit capacitor and a discharge device with a series circuit of a controllable switching element and a load resistor, and a high-voltage battery feeding the power converter on the input side. The power converter has a control equipment to control the switching element, depending on a signal state at an input of the control equipment, to perform a fixed predefined number of switching operations, in which the switching element conducts, with a fixed predefined duration and a fixed predefined delay between two successive switching operations. The load resistor and its heat transfer to the power converter are set so that the load resistor is not damaged if a maximum constant voltage of the high-voltage battery is applied during a respective switching operation.