Joystick control circuit

• US 4,656,456 A
• Filed: 09/11/1985
• Issued: 04/07/1987
• Est. Priority Date: 09/11/1985
• Status: Expired due to Term

• Current Assignee: RCA Corporation (General Electric Company)
• Original Assignee: RCA Corporation (General Electric Company)
• Inventors: Evans, Steven K.
• Primary Examiner(s): Goldberg, E. A.
• Assistant Examiner(s): Lateef, M. M.
• Application Number:
  US06/775,024
• Time in Patent Office: 573 Days
• Field of Search: 338/128, 200/6 R, 200/6 A, 174/471 XY
• US Class Current: 338/128
• CPC Class Codes: G06F 3/0383 Signal control means within the pointing device

Abstract

A control circuit for a joystick includes two dual input NAND gates having one of their inputs connected in common. A potentiometer has a wiper connected to the common NAND gate inputs and has two end terminals each connected to the output of a different NAND gate. A capacitor couples the wiper to ground potential. The control circuit produces a pulsed output signal from one NAND gate when the wiper is moved in one direction from a central position and a pulsed output from the other NAND gate when the wiper is moved in the other direction. The frequency of each NAND output signal varies in relation to the distance that the wiper is moved from the central position.

Claims

1. A control circuit comprising:

first and second dual input logic gates;

a first potentiometer having first and second end terminals and a wiper, the wiper being connected to one input of each of the first and second logic gates, the first end terminal being connected to the output of said first logic gate, the second end terminal being connected to the output of said second logic gate;

a capacitor coupling the wiper of said first potentiometer to a first electrical potential; and

means operatively coupled to said wiper for selectively applying a second electrical potential to the other terminal of one of the first and second logic gates upon the wiper of the first potentiometer moving from a neutral position toward the first or second end terminals respectively;

whereby signals are produced at the outputs of said logic gates with the frequency of said signals varying in a continuous manner in correspondence with the movement of said wiper away from said neutral position.

2. The circuit as in claim 1 wherein said means for applying a second electrical potential comprises a single pole-triple throw switch in which the wiper of the switch is connected to the second potential, one switch end terminal is connected to the other input of the first logic gate and the other switch end terminal is connected to the other input of the second logic gate.

3. The circuit as in claim 1 wherein said means for applying a second electrical potential comprises:

a second potentiometer having first and second end terminals each being connected to the other input terminal of a different one of the first and second logic gates, and having a wiper connected to the second electrical potential, said wiper of the second potentiometer being mechanically connected to said wiper of the first potentiometer;

a first resistor coupling the other input of the first logic gate to said first electrical potential; and

a second resistor coupling the other input of the second logic gate to said first electrical potential.

4. The circuit as in claim 3 herein said first and second resistors have means for varying their resistance.

5. The circuit as in claim 4 wherein said first and second logic gates comprise NAND gates.