US 8,569,984 B2Granted

Motor controller

AssigneePrinceton Technology Corporation

InventorChi-Lin Hsu

Life of this patent

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Abstract

A motor controller controlling a rotational speed of a motor and including a thermal detector, a capacitor, an operational amplifier (OP), a charging/discharging circuit, a flip-flop and a logic circuit. The thermal detector detects environmental temperature of the motor to set a first reference voltage. The capacitor has one terminal coupled to a second reference voltage while another terminal thereof is charged/discharged by the charging/discharging circuit, controlled by a pulse width modulation (PWM) signal, to provide a third reference voltage. The OP compares the first and third reference voltages and outputs the comparison result to a ‘set’ terminal of the flip-flop. The flip-flop further uses a ‘reset’ terminal to receive a clock signal and the output signal thereof is utilized in generating the PWM signal. The PWM signal is further provided to the logic circuit for setting a duty cycle of a driving current of the motor.

Claims10

Dependent claims

A motor controller controlling a motor, comprising

a thermal detector for detecting environmental temperature around the motor to dynamically determine a first reference voltage based on the detected environmental temperature;
a first capacitor having a first terminal and a second terminal, wherein the first terminal is coupled to a second reference voltage;
a first operational amplifier coupled to the second terminal of the first capacitor to receive a third reference voltage and compare the third reference voltage with the first reference voltage;
a charging/discharging circuit charging/discharging the first capacitor based on a pulse width modulation (PWM) signal to change the third reference voltage;
a flip-flop having a set terminal receiving a signal at an output terminal of the first operational amplifier, a reset terminal receiving a clock signal, and an output terminal coupled to the charging/discharging circuit to provide the charging/discharging circuit with the PWM signal;
and
a logic circuit coupled to the output terminal of the flip-flop to determine a duty cycle of a driving current of the motor based on the PWM signal.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 13/271,596Filed 12 Oct 2011
Priority: TW 99134853 A13 Oct 2010
Published: US 2012/0091936 A119 Apr 2012
Granted: 29 Oct 2013
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

H02K 29/08
With position sensing devices: using magnetic effect devices, e.g. Hall-plates, magneto-resistors
G05D 23/1913
Using an analogue comparing device: delivering a series of pulses
G05D 23/24
With sensing elements having variation of electric or magnetic properties with change of temperature: the sensing element having a resistance…
G06F 1/206
Cooling means: comprising thermal management