An electric motor speed controller includes a processor connected to the following terminals, a base voltage terminal receiving a base voltage, a first voltage terminal provided with a constant voltage, and a second voltage terminal receiving a first motor coil voltage from the processor, and a third voltage terminal receiving a second motor coil voltage from the processor. The processor provides a first control period having the second motor coil voltage be zero and a second control period having the first motor coil voltage be zero. The processor determines the motor speed by controlling a difference between a first time period in the first control period and a second time period in the second control period. The first time period corresponds to a first output voltage increase and the second time period corresponds to a second output voltage increase.

A rotation speed regulation system for an electric tool switch includes a controller, a resistance regulating copper foil electrically connected to the controller, and a resistance regulating reed matched with the resistance regulating copper foil. The resistance regulating copper foil includes a first foil and a second foil separated from each other. The first foil is an intact long strip foil. The second foil includes a plurality of short-circuit gold fingers arranged at equal intervals in the middle part and a full-resistance foil and a zero-resistance foil at both ends. The width of the short-circuit gold finger is 0.27 mm, and the distance between two adjacent short-circuit gold fingers is 0.2 mm. An inclination angle α is formed between the short-circuit gold finger and the sliding direction of the resistance regulating contact end, α is 107°-110° and the length L of the contact strip is 2.3-2.9 mm.

A rotation speed regulation system for an electric tool switch includes a controller, a resistance regulating copper foil electrically connected to the controller, and a resistance regulating reed matched with the resistance regulating copper foil. The resistance regulating copper foil includes a first foil and a second foil separated from each other. The first foil is an intact long strip foil. The second foil includes a plurality of short-circuit gold fingers arranged at equal intervals in the middle part and a full-resistance foil and a zero-resistance foil at both ends. The width of the short-circuit gold finger is 0.27 mm, and the distance between two adjacent short-circuit gold fingers is 0.2 mm. An inclination angle α is formed between the short-circuit gold finger and the sliding direction of the resistance regulating contact end, α is 107°-110° and the length L of the contact strip is 2.3-2.9 mm.

A control circuit includes a first high-side transistor coupled between a voltage supply terminal and the first terminal of a DC motor and a second high-side transistor coupled between the voltage supply terminal and the second terminal of the DC motor. The control circuit includes a first low-side transistor coupled between a ground terminal and the first terminal of the DC motor and a second low-side transistor coupled between the ground terminal and the second terminal of the DC motor. The control circuit includes a first pull-up resistor coupled between the voltage supply terminal and a gate terminal of the first low-side transistor and a second pull-up resistor coupled between the voltage supply terminal and a gate terminal of the second low-side transistor. The pull-up resistors apply bias currents to turn ON the first and second low-side transistors to provide a conductive path to brake the DC motor.

A method for driving an electric motor includes providing two controllers for driving the electric motor. The two controllers use different control methods to drive the electric motor. The method further includes selecting a first controller of the controllers as a primary controller to drive the electric motor and a second controller of the controllers as a secondary controller, monitoring a control of the electric motor, and switching the control of the electric motor from the primary controller to the secondary controller if an error condition is detected in the control of the electric motor.

A drive control device and a drive control method for electric motors are capable of detecting a leakage current in a multilayer wiring board without providing a current sensor. The drive control device has an inverter circuit mounted on the multilayer wiring board, and a shunt resistor for detecting a bus current in the inverter circuit. The upstream and downstream wiring portions of the inverter circuit are disposed facing each other in neighboring layers of the multilayer wiring board, with insulating layers interposed therebetween. The multilayer wiring board has a sensing pattern layer which guides, to the shunt resistor, the leakage current flowing from the upstream wiring portion to the downstream wiring portion, and the presence or absence of leakage current is determined based on the current flowing through the shunt resistor during the period in which the regenerative current is generated in the electric motor.

An electric motor speed controller includes a processor connected to the following terminals, a base voltage terminal receiving a base voltage, a first voltage terminal provided with a constant voltage, and a second voltage terminal receiving a first motor coil voltage from the processor, and a third voltage terminal receiving a second motor coil voltage from the processor. The processor provides a first control period having the second motor coil voltage be zero and a second control period having the first motor coil voltage be zero. The processor determines the motor speed by controlling a difference between a first time period in the first control period and a second time period in the second control period. The first time period corresponds to a first output voltage increase and the second time period corresponds to a second output voltage increase.

A window control device for a vehicle, and a method therefor, include a driving motor configured to drive a window glass, a first sensor configured to generate one pulse signal corresponding to a rotation of the driving motor, a second sensor configured to sense a voltage signal provided to the driving motor, and a controller configured to perform a safety function based on the one pulse signal generated by the first sensor and the voltage signal sensed by the second sensor. Although a fault occurs in one of two hall sensors, the window control device may normally perform the safety function.

A drive control device and a drive control method for electric motors are capable of detecting a leakage current in a multilayer wiring board without providing a current sensor. The drive control device has an inverter circuit mounted on the multilayer wiring board, and a shunt resistor for detecting a bus current in the inverter circuit. The upstream and downstream wiring portions of the inverter circuit are disposed facing each other in neighboring layers of the multilayer wiring board, with insulating layers interposed therebetween. The multilayer wiring board has a sensing pattern layer which guides, to the shunt resistor, the leakage current flowing from the upstream wiring portion to the downstream wiring portion, and the presence or absence of leakage current is determined based on the current flowing through the shunt resistor during the period in which the regenerative current is generated in the electric motor.

A variable-speed controller for use with an electric device including: a variable resistor element having a variable resistor element contact surface; a membrane including a first membrane contact surface spaced-apart from the variable resistor element contact surface by a spacer element, and, a second membrane contact surface; a slider configured for slidable movement along the second membrane contact surface wherein responsive to the slider slidably moving along the second membrane contact surface, the first membrane contact surface is able to be urged into contact with the variable resistor element contact surface in a plurality of contact point configurations whereby the effective resistance of the variable resistor element is configured to change in response to the first membrane contact surface being urged into contact with the variable resistor element contact surface in each of the plurality of contact point configurations.