A main circuit power source and a control power source of a motor drive device are backed up. A first backup capacitor is inserted between a rectifier and a control power source output terminal that supplies power to a control circuit of a driver.

A main circuit power source and a control power source of a motor drive device are backed up. A first backup capacitor is inserted between a rectifier and a control power source output terminal that supplies power to a control circuit of a driver.

According to an example aspect of the present invention, there is provided a DC to DC converter module for use between an electric power source and an electric motor. The DC to DC converter module having: a DC to DC converter; input terminals configured to provide a source voltage to the DC to DC converter from the electric power source; output terminals connected to outputs of the DC to DC converter and configured to provide an output voltage of the DC to DC converter module to the electric motor; and control circuitry connected to the DC to DC converter, the control circuitry having an input for receiving a signal indicative of a desired electric motor performance. The control circuitry being configured to control the DC to DC converter in order to adjust the output voltage based at least partially on the signal indicative of a desired electric motor performance.

According to an example aspect of the present invention, there is provided a DC to DC converter module for use between an electric power source and an electric motor. The DC to DC converter module having: a DC to DC converter; input terminals configured to provide a source voltage to the DC to DC converter from the electric power source; output terminals connected to outputs of the DC to DC converter and configured to provide an output voltage of the DC to DC converter module to the electric motor; and control circuitry connected to the DC to DC converter, the control circuitry having an input for receiving a signal indicative of a desired electric motor performance. The control circuitry being configured to control the DC to DC converter in order to adjust the output voltage based at least partially on the signal indicative of a desired electric motor performance.

A power supply voltage terminal and a ground terminal having a rectangular cross section are respectively connected to a first terminal hole of a power supply pattern and a second terminal hole of a ground pattern. An inductor is surface-mounted on a substrate, and has a rectangular parallelepiped shape in which an input end connected to a power supply pattern and an output end connected to a power supply relay face each other. A first electrode terminal of a capacitor is connected to the power supply pattern, a second electrode terminal is connected to the ground pattern, and constitutes a filter circuit together with the inductor. A wall surface of an input end of the inductor is arranged parallel to the longitudinal axis direction (x direction) of the first terminal hole. The inductor opposes the first terminal hole so as to include the entire length Wh of the first terminal hole within the width Wt of the input end in the x direction.

A power supply voltage terminal and a ground terminal having a rectangular cross section are respectively connected to a first terminal hole of a power supply pattern and a second terminal hole of a ground pattern. An inductor is surface-mounted on a substrate, and has a rectangular parallelepiped shape in which an input end connected to a power supply pattern and an output end connected to a power supply relay face each other. A first electrode terminal of a capacitor is connected to the power supply pattern, a second electrode terminal is connected to the ground pattern, and constitutes a filter circuit together with the inductor. A wall surface of an input end of the inductor is arranged parallel to the longitudinal axis direction (x direction) of the first terminal hole. The inductor opposes the first terminal hole so as to include the entire length Wh of the first terminal hole within the width Wt of the input end in the x direction.

With respect to a failure in voltage sensors each for detecting a high-voltage-side voltage in a DC/DC converter, it is so arranged that a circuit failure of the DC/DC converter is prevented, and that the DC/DC converter is continuingly controlled. Two voltage sensors are included therein each for detecting a high-voltage-side voltage, so that, even when a first voltage sensor for detecting a high-voltage-side voltage on one side fails to work properly, a control device turns on a second switching device, and detects a voltage by a second voltage sensor for detecting the high-voltage-side voltage on the other side, whereby a failure of the voltage sensor for detecting the high-voltage-side voltage is detected.

With respect to a failure in voltage sensors each for detecting a high-voltage-side voltage in a DC/DC converter, it is so arranged that a circuit failure of the DC/DC converter is prevented, and that the DC/DC converter is continuingly controlled. Two voltage sensors are included therein each for detecting a high-voltage-side voltage, so that, even when a first voltage sensor for detecting a high-voltage-side voltage on one side fails to work properly, a control device turns on a second switching device, and detects a voltage by a second voltage sensor for detecting the high-voltage-side voltage on the other side, whereby a failure of the voltage sensor for detecting the high-voltage-side voltage is detected.

An electric drive apparatus includes a DC motor for driving the electric device; a DC power source for outputting constant-voltage DC power to the DC motor; and a chopper for converting the constant-voltage DC power into variable-voltage DC power according to a driving signal and providing the variable-voltage DC power to the DC motor. The DC motor has 2j armature winding branches, each of which consists of m windings, 2jm commutator segments connected to the windings, and two brush sets respectively connected to two power line sets of the DC motor and in contact with the commutator segments.

An electric drive apparatus includes a DC motor for driving the electric device; a DC power source for outputting constant-voltage DC power to the DC motor; and a chopper for converting the constant-voltage DC power into variable-voltage DC power according to a driving signal and providing the variable-voltage DC power to the DC motor. The DC motor has 2j armature winding branches, each of which consists of m windings, 2jm commutator segments connected to the windings, and two brush sets respectively connected to two power line sets of the DC motor and in contact with the commutator segments.