On the outset, it may be due to wheels as in the case of an automobile. What actually drives these movements, though, are motors. Additionally, many household appliances such refrigerators, air-conditioners, ventilation fans, washers, driers and so many others all... Read more

The post Yup, it’s the motor drive that makes systems in motion all around us appeared first on EEP - Electrical Engineering Portal.

A driving circuit for a single-phase-brushless motor includes a driving-signal-generating circuit to generate a driving signal for supplying, to a driving coil of the single-phase-brushless motor, first- and second-driving currents alternately with a de-energized period therebetween, an output circuit, and a zero-cross-detecting circuit. While measuring a driving cycle from a start of an energized period, during which the output circuit supplies the first- or the second-driving current to the driving coil, to a time when the zero-cross-detecting circuit detects a zero cross of an induced voltage, generated across the driving coil, during the de-energized period, the driving-signal-generating circuit determines a length of a subsequent energized period based on the measured driving cycle, when the zero-cross-detecting circuit detects the zero-cross, and the driving-signal-generating circuit determines a length of an immediately previous energized period as a length of a subsequent energized period, when the zero-cross-detecting circuit does not detect the zero-cross.

The present invention relates to a drive apparatus and drive method for switching an energization mode when a voltage of a non-energized phase of a brushless motor crosses a threshold. In threshold learning, first, the brushless motor is stopped at an initial position. The brushless motor is then rotated by performing phase energization based on the energization mode from the stopped state. The voltage of the non-energized phase at an angular position of switching the energization mode is detected from a maximum value or a minimum value of the voltage of the non-energized phase during the rotation, and the threshold is learned based on the detected voltage. Alternatively, the brushless motor is positioned at the angular position of switching the energization mode by maintaining one energization mode, and then the energization mode is switched to the next energization mode. The voltage of the non-energized phase immediately after the switching to the energization mode is detected, and the detected voltage of the non-energized phase is learned as the threshold used to determine the timing of switching to the next energization mode.

A switching element is switched off after having been switched on for only a short time interval called a first predetermined time interval, and a determination is made, based on a mode of a change in a contact point potential (a regeneration voltage) between an electric motor and the switching element when the switching element as switched off, as to whether or not one of the electric motor and the switching element has failed. Next, the switching element is switched on for a time interval called a second predetermined time interval, which is longer than the first predetermined time interval, and a determination is made, based on the magnitude of the contact point potential at that time, as to which one of the electric motor and the switching element has failed. It is thus possible for a failure of the switching element and electric motor to be detected.

A system to monitor the temperature of power electronic devices in a motor drive includes a base plate defining a planar surface on which the electronic devices and/or circuit boards within the motor drive may be mounted. The power electronic devices are mounted to the base plate through the direct bond copper (DBC). A circuit board is mounted to the base plate which includes a temperature sensor mounted on the circuit board proximate to the power electronic devices. The temperature sensor generates a digital signal corresponding to the temperature measured by the sensor. A copper pad is included between each layer of the circuit board and between the first layer of the circuit board and the sensor. The circuit board also includes vias extending through each layer of the board. The copper pads and vias establish a thermally conductive path between the temperature sensor and the base plate.

A motor driven power steering (MDPS) may include: a vehicle speed sensor configured to sense vehicle speed; a temperature sensor configured to sense a temperature of a power pack; a current sensor configured to sense an amount of current applied to the MDPS; a storage unit configured to store a thermal resistance value based on the vehicle speed with respect to the temperature of the power pack; and a control unit configured to calculate an estimated temperature by reflecting the thermal resistance value based on the vehicle speed with respect to the temperature of the power pack and the current amount applied to the MDPS into a temperature estimation function, and drive a motor according to the calculated estimated temperature.

A wireless small motor driver, in which power consumption is decreased by adjusting a gear ratio, the efficiency of an operation is increased due to a high torque, and the safety of a worker at night is ensured using an illumination lamp. The wireless small motor driver includes a driver case inside of which a motor is provided. A driver bit has a predetermined length in a bilateral direction, the driver bit being replaceable, with one or both ends thereof conforming to the shape of a bolt, and has a fixing projection. A socket is coupled to an end portion of the driver case, the driver bit being fastened to the socket. A rotation reduction gear is coupled to the motor, the rotation reduction gear transmitting rotary force to the socket and increasing a torque. A USB and a battery for supplying uniform power to the motor are added.

A motor drive assembly can prevent a two-way roller clutch of the current speed ratio and a two-way roller clutch of the next speed ratio from engaging simultaneously, and includes a first-speed friction plate formed with engaging protrusions on the first-speed side, and a shift ring formed with engaging recesses. While the shift ring is in a first-speed shift position SP1f, the engaging protrusions are adapted to be engaged in the engaging recesses, thereby preventing rotation of the shift ring relative to the first-speed friction plate. The shift ring is provided with projections on its inner periphery. The drive assembly further includes an annular protrusion formed with cutouts. When the projections are axially and circumferentially displaced from the respective cutouts, the projections are adapted to interfere with the annular protrusion, thereby preventing axial movement of the shift ring between the first-speed shift position SP1f and a second-speed shift position SP2f.

A motor drive device is fixed to a wall part of a housing and comprises a duct having an inflow port and an outflow port of air. A main body part of the duct functions as a heat-sink unit which releases heat into the duct. The duct is arranged inside the housing. The inflow port and the outflow port are formed so that outside air can flow through openings formed in the wall part.

Singapore : Springer, c2019.

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