Touch responsive circuit

• US 3,200,306 A
• Filed: 09/12/1963
• Issued: 08/10/1965
• Est. Priority Date: 09/12/1963
• Status: Expired due to Term

• Current Assignee: Edison International
• Original Assignee: Carl E. Atkins, Robert L. Ziolkowski
• Inventors: Atkins, Carl E., Ziolkowski, Robert L.
• Application Number:
  US04/308,505
• Time in Patent Office: 698 Days
• US Class Current: 361/179
• CPC Class Codes: G08B 13/26 by proximity of an intruder causing variation in capacitance or inductance of a circuit
• CPC Class Codes: H03K 17/962 Capacitive touch switches

Claims

1. A TOUCH RESPONSIVE CIRCUIT WHICH OPERATES ON A SOURCE OF D.C. POTENTIAL COMPRISING:

(A) A CAPACITOR;

(B) A CHARGING CIRCUIT COUPLING SAID CAPACITOR TO THE SOURCE OF D.C. POTENTIAL FOR CHARGING SAID CAPACITOR TO A FIRST LEVEL D.C. POTENTIAL;

(C) A SEMICONDUCTOR SWITCHING DEVICE COUPLED ACROSS THE CAPACITOR TO DISCHARGE SAID CAPACITOR TO A SECOND LEVEL OF D.C. POTENTIAL WHEN SAID SEMICONDUCTOR SWITCHING DEVICE IS CONDUCTIVE;

(D) AN OSCILLATOR COUPLED TO SAID SEMICONDUCTOR SWITCHING DEVICE TO PROVIDE PULSES TO RENDER SAID SEMICONDUCTOR SWITCHING DEVICE CONDUCTIVE;

(E) TOUCH RESPONSIVE MEANS COUPLED TO SAID OSCILLATOR TO SUPPRESS THE MAGNITUDE OF THE PULSES SUPPLIED TO THE OSCILLATOR WHEN THE TOUCH RESPONSIVE MEANS IS TOUCHED TO RENDER THE SEMICONDUCTOR SWITCHING DEVICE NON-CONDUCTIVE;

AND (F) CIRCUIT CONTROLLING MEANS RESPONSIVE TO THE LEVEL OF POTENTIAL ACROSS SAID CAPACITOR.