Electronic switch activated by current flow through the human body

In a portable instrument capable of being in contact with the body of the wearer during operation, an electronic circuit, said electronic circuit comprising:

• a. an electronic switch having two states, at least one of which is a stable state, said electronic circuit having at least one data input terminal and one data output terminal;
• b. a source of voltage having two terminals;
• c. said instrument having a conductive casing, one terminal of said voltage source being connected to said casing;
• d. an insulating panel disposed in said casing and having apertures therethrough;
• e. said circuit having one control terminal, said control terminal including a conductive portion recessed in an aperture of said insulating panel;
• f. a resistor connected between the other terminal of said voltage source and said control terminal, whereby when the wearer contacts said control terminal, a current will flow through the body of the wearer to cause the voltage of said control terminal to approach that of the other terminal of said voltage source, thereby to trigger said circuit to its other state.

In combination with a digital watch capable of being in contact with the body of a wearer during operation;

• a. said watch including a crystal-controlled oscillator;
• b. a control logic coupled to said oscillator;
• c. a multiplexed digital display;
• d. a first digital calculator having control terminals for the digits from zero to 9, a plurality of predetermined mathematical functions and a plurality of additional operations including a memory storage, memory recall and the like;
• e. each of said digits functions and operations being energizable by an electronic circuit having two states, at least one of which is a stable state;
• f. each of said electronic circuits including a data input terminal and a data output terminal;
• g. a voltage source having two terminals;
• h. said watch and calculator having a common conductive casing, one terminal of said voltage source being connected to said casing, said circuit including a control terminal;
• i. a resistor connected between the other terminal of said voltage source and said control terminal;
• j. an additional resistor connected in series with said control terminals, whereby a current through the body of the wearer can be made to flow by contacting the control terminal;
• k. a metallic element to switch said electronic switch into the other one of its states to permit data to pass therethrough;
• and
• l. a second digital calculator coupled to said electronic circuits and having its output coupled to said didgital display for displaying the result of a calculation.

In a digital watch of the type including a digital time calculator and a digital calculator:

• a. a conductive casing for said watch;
• b. a watch face of insulating material having a plurality of openings, each for activating a predetermined function or operation;
• c. an insulating layer spaced from and disposed below said watch face;
• and
• d. a plurality of conductive layers on said insulating layer, each being associated with one of said openings for energizing a circuit associated therewith by contacting said conductive layer through said one of said openings with a conductive element.

In a digital watch of the type including a digital time calculator and a digital calculator;

• a. a conductive casing for said watch;
• b. a watch face having a plurality of openings, each for activating a predetermined function or operation;
• c. an insulating layer spaced from said watch face;
• d. a plurality of conductive layers on said insulating layer, each being associated with one of said openings for energizing a circuit associated therewith by contacting said conductive layer with a conductive element;
• e. a metallic pin;
• and
• f. means for removably securing said pin to said casing, said pin being capable of contacting a selected conductive layer through its associated opening.