Dual channel wide-band frequency modulated keyable control circuit and keying circuit therefor

A keyable control circuit and keying circuit therefor as recited in claim 10 wherein said means for connecting is an electrically operated switch comprising:

• a. an rf bypass capacitor connected at its first end to said oscillator;
• b. a diode connected at its first end to the second end of said bypass capacitor;
• c. a current source connected through an rf choke to the junction of said bypass capacitor and diode;
• and
• d. means for selectively causing said diode to become conducting or non-conducting.

A keyable control circuit and keying circuit therefor comprising:

• a. a plurality of oscillators;
• b. means for cyclically sweeping the frequency of said plurality of oscillators;
• c. a first sensing coil receiving swept energy from a first of said plurality of oscillators;
• d. at least a second sensing coil receiving swept energy from at least second of said plurality of oscillators;
• e. means for cyclically enabling each of said first and second oscillators into operation;
• f. keying circuit means for generating first and second signals each time the frequency of said first oscillator is swept past first and second frequency regions;
• g. first output means operative in responsive to gating on of said first oscillator and the simultaneous presence of said first and second signals to generate a first control output signal, said first output means being adapted to prevent generation of said first control output in the absence of one or more of the following:
• i. oscillation in said first oscillator,
• ii. said first signal, and
• iii. said second signal;
• and
• h. at least a second output means operative in response to gating on of said second oscillator and the simultaneous presence of said first and second signals to generate a second control output signal, said second output means being adapted to prevent generation of said second control output in the absence of one or more of the following:
• i. oscillation in said second oscillator
• ii. said first signal, and
• iii. said second signal.

A method of keyably controlling an electrical circuit using a keying circuit having at least one resonant frequency comprising:

• a. generating oscillations;
• b. connecting energy from said oscillations to at least first and second spaced locations;
• c. generating a first signal when a keying circuit having said at least one resonant frequency is coupled to any one of said at least first and second spaced locations;
• d. generating a second signal when said keying circuit is coupled to said first spaced location;
• and
• e. generating at least a third signal when said keying circuit is coupled to at least said second spaced location.