Touch-actuated electronic switch

• US 4,169,982 A
• Filed: 12/08/1977
• Issued: 10/02/1979
• Est. Priority Date: 12/08/1977
• Status: Expired due to Term

• Current Assignee: Albert D. Rittmann
• Original Assignee: Albert D. Rittmann
• Inventors: Rittmann, Albert D.
• Primary Examiner(s): Hix, L. T.
• Assistant Examiner(s): Schreyer, S. D.
• Application Number:
  US05/858,535
• Time in Patent Office: 663 Days
• Field of Search: 307/116, 361/179, 361/181
• US Class Current: 307/116
• CPC Class Codes: H03K 17/962 Capacitive touch switches

Abstract

A touch-actuated electronic switch is disclosed including a direct current or voltage supply having its output or common terminal connected to a voltage source which is alternating with respect to Earth ground, two signal inputs, at least one touch surface, means for connecting the touch surface to one of the signal inputs, an amplifying device and a network for imposing part of the signal found on the signal inputs onto the amplifying device. A mode of operation is disclosed wherein the amplifying device is allowed to float up and down in voltage to follow in part the alternating voltage of the signal inputs. The above arrangement can be used, through the addition of additional circuitry, to switch the power to a load on and off any time the touch surface is first touched.

Claims

1. A touch-actuated electronic switch, comprising in combination:

a direct current or voltage supply with output and common terminals;

a voltage source alternating with respect to Earth ground;

means for connecting said alternating voltage source to either the output or common terminal of the direct current or voltage supply such that the output terminal of the direct current or voltage supply has imposed on it all or part of the alternating voltage of said alternating voltage source;

first signal input means;

second signal input means;

at least one touch surface;

means for providing electrical connection between the touch surface and one of the input means;

an amplifying device having at least three terminals, the relative voltage of the first terminal and the second terminal determining the voltage of or the current drawn by the third terminal;

two or more resistors in series joining the first signal input means to a first voltage reference point, the common point of two of these resistors being connected to the first terminal of the amplifying device;

two or more resistors in series joining a second signal input means to a second voltage reference point, the common point of two of these resistors being connected to the second terminal of the amplifying device; and

third circuit means for controlling the power to a load or performing some other useful function depending on the voltage of or the current drawn by the third terminal of the amplifying device.

2. The touch-actuated electronic switch of claim 1 wherein the amplifying device is a transistor with the base being the first terminal of the amplifying device, the emitter being the second terminal of the amplifying device and the collector being the third terminal of the amplifying device.