Compensating outputs of hall generators to minimize effects of temperature variation and the like

Claim 2

In an electronic power supply for a commutatorless DC motor which includes a permanently magnetized rotor for generating a magnetic field, a stator winding arrangement comprising at least one stator coil positioned in torque-producing arrangement consisting of a single stationary Hall generator disposed in magnetic field sensing relation to said rotor so as to develop first and second voltage output signals at first and second output terminals thereof, and control circuitry connected to said output terminals for energizing and deenergizing said at least one stator coil in response to rotor position, the improvement comprising first and second amplifier stages each having an input and an output, the first stage having its input connected to the first output terminal and the second stage having its input connected to the second output terminal, the outputs of said first and second stages being connected to the control circuitry, first and second feedback networks connected between the input and the output of the first and of the second stage, respectively, and said control circuitry including non-linear control means responsive to output signals from said first and second stages for preventing current flow through said stator coil when the magnetic field is below a predetermined threshold value and for passing current through said stator coil when the magnetic field exceeds said value.

Claim 3

The improvement defined by claim 1, wherein each of said feedback networks comprises a feedback resistance which is high as compared with the internal resistance, to accomplish in addition to the compensation also an amplification of the output signal of said Hall generator.

Claim 4

A brushless DC motor arrangement comprising a permanent magnetic rotor for generating a magnetic field, a stator winding arrangement comprising at least one stator coil positioned in torque-producing relation to said rotor, a rotor position sensing arrangement consisting of a stationary Hall generator defining an internal resistance between first and second output terminals thereof and disposed in magnetic field sensing relation to said rotor so as to develops first and second magnetic field responsive output signals at said first and second output terminals, first and second amplifier stages each having an input and an output, the first stage having its input connected to the first output terminal and the second stage having its input connected to the second output terminal, and control circuitry linked to the outputs of said first and second amplifier stages for energizing and deenergizing said at least one stator coil in response to the position of the rotor, said control circuitry comprising converter means having first and second inputs connected to the output terminals of said first and second amplifier stages for converting the output signals of said first and second amplifier stages into a magnetic field strength signal having an amplitude propertional to the magnitude of the strength of said magnetic field, current sensing means for generating a coil current signal substantially proportional to the current flowing through said at least one stator coil, and current control means responsive to said magnetic field strength signal and to said coil current signal for controlling the current through said stator coil so as to be substantially proportional to the sensed magnitude of the magnetic field strength.

Claim 5

A brushless DC motor arrangement comprising a permanent magnetic rotor for generating a magnetic field, a stator winding arrangement comprising at least one stator coil positioned in torque-producing relation to said rotor, a rotor position sensing arrangement consisting of a stationary Hall generator defining an internal resistance between first and second output terminals thereof and disposed in magnetic field sensing relation to said rotor so as to develops first and second magnetic field responsive output signals at said first and second output terminals, first and second amplifier stages each having an input and an output, the first stage having its input connected to the first output terminal and the second stage having its input connected to the second output terminal, and control circuitry linked to the outputs of said first and second amplifier stages for energizing and deenergizing said at least one stator coil in response to the position of the rotor, said control circuitry comprising converter means having first and second inputs connected to the output terminals of said first and second amplifier stages for converting the output signals of said first and second amplifier stages into a magnetic field strength signal having an amplitude propertional to the magnitude of the strength of said magnetic field, current sensing means for generating a coil current signal substantially proportional to the current flowing through said at least one stator coil, and current control means responsive to said magnetic field strength signal and to said coil current signal for controlling the current through said stator coil so as to be substantially proportional to the sensed magnitude of the magnetic field strength.

Claim 6

The arrangement as defined in claim 3, wherein said control circuitry comprises a first capacitor connected between the output of said first amplifier stage and said first input of said converter means and a second capacitor connected between the output of said second amplifier stage and said second input of said converter means for passing the output signals of said first and second amplifier stages to said converter means when said rotor rotates, and for blocking the passage of the output signals of said first and second amplifier stages to said converter means and causing said current control means to shut off the flow of current through said stator coil when said rotor is prevented from rotating.

Claim 7

A brushless DC motor arrangement comprising a permanent magnetic rotor for generating a magnetic field, a stator winding arrangement comprising at least one stator coil positioned in torque-producing relation to said rotor, a rotor position sensing arrangement consisting of a single stationary Hall generator defining an internal resistance between first and second output terminals thereof and disposed in magnetic field sensing relation to said rotor so as to develop first and second magnetic field responsive output signals at said first and second output terminals, first and second amplifier stages each having an input and an output, the first stage having its input connected to the first output terminal and the second stage having its input connected to the second output terminal, first and second feedback networks connected between the input and the output of the first and second amplifier stage, respectively, for compensating variations of said internal resistance, control circuitry linked to the outputs of said first and second amplifier stages for energizing and deenergizing said at least one stator coil in response to the position of the rotor, and said control circuitry including non-linear control means responsive to output signals from said first and second stages for preventing current flow through said stator coil when the magnetic field is below a predetermined threshold value and for passing current through said stator coil when the magnetic field exceeds said value.

Claim 8

A brushless DC motor arrangement comprising a permanent magnetic rotor for generating a magnetic field, a stator winding arrangement comprising at least one stator coil positioned in torque-producing relation to said rotor, a rotor position sensing arrangement consisting of a single stationary Hall generator defining an internal resistance between first and second output terminals thereof and disposed in magnetic field sensing relation to said rotor so as to develop first and second magnetic field responsive output signals at said first and second output terminals, first and second amplifier stages each having an input and an output, the first stage having its input connected to the first output terminal and the second stage having its input connected to the second output terminal, first and second feedback networks connected between the input and the output of the first and second amplifier stage, respectively, for compensating variations of said internal resistance, control circuitry linked to the outputs of said first and second amplifier stages for energizing and deenergizing said at least one stator coil in response to the position of the rotor, and said control circuitry including non-linear control means responsive to output signals from said first and second stages for preventing current flow through said stator coil when the magnetic field is below a predetermined threshold value and for passing current through said stator coil when the magnetic field exceeds said value.

Claim 9

The arrangement as defined in claim 5, wherein said non-linear control means comprises at least one non-linear amplifier stage.