ELECTRONIC ACCELERATOR CONTROL FOR ELECTRIC VEHICLE

• US 3,818,292 A
• Filed: 11/17/1972
• Issued: 06/18/1974
• Est. Priority Date: 11/17/1972
• Status: Expired due to Term

• Current Assignee: Alby M. Berman
• Original Assignee: Alby M. Berman
• Inventors: Berman, Alby M.
• Primary Examiner(s): Gilheany, Bernard A.
• Assistant Examiner(s): Langer, Thomas
• Application Number:
  US05/307,686
• Time in Patent Office: 578 Days
• Field of Search: 318/129,341 324/34PS,34D,45 307/309
• US Class Current: 318/139
• CPC Class Codes: H02P 7/29 using pulse modulation

Abstract

A vehicle powered by a storage battery employs a foot pedal which adjusts the position of a permanent magnet relative to a Hall effect device. The voltage output from the Hall effect device, a non-linear function of the magnet position, is used to control the frequency of a fixed pulse width chopper which applies a battery current to the drive motor.

Claims

1. A speed control for a vehicle having an electric power source and an electric drive motor including means for generating a magnetic field;

a semi-conductor means having an electrical output which is a nonlinear function of its distance from said field generating means;

field;

means for supporting the semiconductor device and the magnetic field generating means for relative motion toward and away from one another; and

means for controlling power flow from the power source to the drive motor as a function of the output of the semi-conductor device whereby the power flow is a non-linear function of the relative position between the semi-conductor device and the magnetic field generating means.

2. The speed control of claim 1 wherein the semi-conductor means comprises a Hall effect device having a voltage output which is a function of the magnetic field applied to the device.

3. The speed control device of claim 1 including a foot pedal supported for motion relative to the vehicle frame and connected to either the semi-conductor means or the means for generating magnetic fields so that the relative positions of the semi-conductor means and the means for generating magnetic fields may be varied by pressing the pedal.

4. The speed control device of claim 1 wherein said means for controlling power flow from the power source to the drive motor as a function of the output of the semi-conductor means includes a chopper circuit connected to the semi-conductor means so as to have a period of conduction which is a function of the output of the semi-conductor means.

5. The speed control device of claim 1 wherein the semi-conductor means comprises a Hall effect device having a current passed through it from said electric power source.

6. The speed control device of claim 5 wherein the electrical output of the Hall effect device is applied to a voltage controlled oscillator to generate a signal having a variable frequency proportional to suCh electrical output, the means for controlling the power flow from the power source to the drive motor as a function of the output of the semi-conductor means constitutes a chopper, and the chopper conduction period is controlled by said variable frequency signal.

7. An accelerator control for a vehicle having an electric power source and an electric drive motor, comprising:

a pedal supported on said vehicle for motion toward and away from a surface of said vehicle;

means for biasing said pedal away from said surface;

means for generating a magnetic field;

a semi-conductor means having an electric output which is a nonlinear function of its distance from said field generating means;

means for supporting one of said semi-conductor devices and said means for generating a magnetic field on the pedal and for supporting the other on the vehicle so that motion of the pedal relative to the vehicle varies the distance between said semi-conductor device and said means for generating a magnetic field; and

means for controlling power flow from the power source to the drive motor as a function of the output of the semi-conductor device.

8. The accelerator device of claim 7 wherein said means for controlling power flow from the power source to the drive motor constitutes a chopper connected between said electrical power source and said electric drive motor.

9. The accelerator control of claim 8 wherein the chopper is a fixed pulse width variable frequency type and its frequency of operation is controlled as a function of the output of the semi-conductor means.

10. The accelerator control of claim 7 wherein the semi-conductor means comprises a Hall effect device.

11. The accelerator control of claim 7 wherein said means for generating a magnetic field constitutes a permanent magnet.

12. A speed control for a vehicle having an electric power source and an electric drive motor comprising a foot pedal pivotally supported with respect to the vehicle;

spring means for biasing one end of said foot pedal away from said vehicle;

a Hall effect semi-conductor device and a permanent magnet, one being affixed to the foot pedal and the other affixed to the vehicle so that motion of the foot pedal toward and away from the vehicle varies the position of the magnet relative to the position of the semi-conductor device; and

a power source operative to pass current through said Hall effect device;

a variable frequency oscillator connected to the voltage output of said Hall effect device so as to provide an output signal having a frequency which is a function of the voltage output of the Hall effect device;

a chopper connected between said power source and said electric drive motor; and

means for controlling the period of conduction of said chopper as a function of the frequency of said voltage controlled oscillator, whereby the power applied from said power source to said drive motor is a non-linear function of the position of the foot pedal relative to the vehicle.