ELECTRONIC LATCHING DEVICE

• US 3,699,359 A
• Filed: 04/20/1971
• Issued: 10/17/1972
• Est. Priority Date: 04/20/1971
• Status: Expired due to Term

• Current Assignee: Rufus F. Shelby
• Original Assignee: Rufus F. Shelby
• Inventors: Shelby, Rufus F.
• Primary Examiner(s): Rolinec, Rudolph V.
• Assistant Examiner(s): Carter, David M.
• Application Number:
  US05/135,544
• Time in Patent Office: 546 Days
• Field of Search: 307/221,252K,252Q,305,288,292,255,308 334/7 325/465
• US Class Current: 327/187
• CPC Class Codes: H03J 5/0218 Discontinuous tuning using an electrical variable impedance element, e.g. a voltage variable reactive diode, by selecting the corresponding analogue value between a set of preset values
• CPC Class Codes: H03K 17/962 Capacitive touch switches

Abstract

A momentary contact touch switch operates an electronic latching circuit which applies a constant direct current to a potentiometer. The potentiometer arm produces a controlled output voltage suitable for the remote electronic control of circuits having voltage sensitive variable capacitor tuning elements. A plurality of such devices operate as a touch-button tuning control with the potentiometers acting as the tuning controls to preset the touch-buttons. The voltage outputs of the potentiometers are fed through isolating diodes to a common control voltage output line so that only the potentiometer that is energized will be electrically connected to the output. All of the latching circuits are connected to a common element so that when any one circuit is actuated by a touch button, all of the others are deenergized.

Claims

1. A switching circuit for use with a radio frequency tuner employing a voltage variable reactance tuning element, including a plurality of means for supplying an adjustable voltage to said voltage variable reactance so that said tuner can be adjusted to any one of a plurality of frequencies at will by actuating one of a plurality of momentary contact switches, said circuit comprising:

a. a source of regulated direct current;

b. a plurality of electronic latching circuits, each latching circuit containing a momentary contact push button switch, a potentiometer, and active circuit elements connected to provide two stable electrical states, an '"'"''"'"''"'"''"'"'on'"'"''"'"''"'"''"'"' state wherein said potentiometer is connected through said active circuit element to said source of regulated direct current, and an '"'"''"'"''"'"''"'"'off'"'"''"'"''"'"''"'"' state wherein said potentiometer is isolated from said source of regulated direct current, said on state being actuated by said switch;

c. means common to said plurality of electronic latching circuits and responsive to the actuation to the '"'"''"'"''"'"''"'"'on'"'"''"'"''"'"''"'"' state of a selected one of said latching circuits for actuating the '"'"''"'"''"'"''"'"'off'"'"''"'"''"'"''"'"' state in non-selected latching circuits; and

d. means for connecting said potentiometers to a common output line while isolating from said common output line all potentiometers associated with a latching circuit in the '"'"''"'"''"'"''"'"'off'"'"''"'"''"'"''"'"' state.

2. The switching circuit of claim 1 including means for indicating which latching circuit is in the '"'"''"'"''"'"''"'"'on'"'"''"'"''"'"''"'"' state.

3. The switching circuit of claim 1 wherein said active circuit elements comprises a pair of complementary transistors.

4. The switching circuit of claim 1 wherein said means for connecting comprises a semiconductor diode for each electronic latching circuit.

5. The switching circuit of claim 2 wherein said means for indicating comprises lamp elements connected in parallel with said potentiometers.