Method and apparatus for converting electrical signals

Claim 2

In a television signal frequency converter apparatus including an impedance element having a variable reactance dependent upon the magnitude of a voltage applied across two terminals thereof, electrical circuitry for tuning said apparatus comprising: a plurality of tuning potentiometers each of said potentiometers having two end connections and a variable tap; a source of d.c. potential having a reference point and operative to energize said potentiometers; a first output bus; a second output bus; a plurality of multiple pole switches, each of said switches being associated with two of said potentiometers and being operative to enable the application of a voltage developed at the variable tap of the first potentiometer associated therewith to the first output bus and a voltage at the variable tap of the second potentiometer associated therewith to the second output bus; an output line coupled to one of said variable reactance element terminals; switch means for selectively coupling said output line to said first or second bus; and means coupling said other variable reactance element terminal to said d.c. potential source reference point.

Claim 3

The tuning circuitry of claim 1 wherein the first end connection of each of said tuning potentiometers are coupled to a first circuit point, the second end connections of each of said tuning potentiometers are connected to a second circuit point, the variable tap of each of said potentiometers is individually coupled to a terminal of the multiple pole switch with which it is associated and each of said first and second circuit points are coupled to said source of d.c. potential.

Claim 4

The tuning circuitry of claim 2 further comprising a first variable resistance couPling said first circuit point to said source of d.c. potential and a second variable resistance coupling said second circuit point to said source of d.c. potential.

Claim 5

The tuning circuitry of claim 3 further comprising means for simultaneously varying the resistances of said first and second variable resistances such that the resistance of one of said first and second variable resistances decreases as the resistance of the other of said first and second variable resistance increases.

Claim 6

A television signal frequency converter apparatus including an impedance element having a variable reactance dependent upon the magnitude of a voltage applied across two terminals thereof, electrical circuitry for tuning said apparatus comprising: a plurality of tuning potentiometers each of said potentiometers having two end connections and a variable tap; a source of d.c. potential; means for coupling one end connection of each of said plurality of potentiometers to a first terminal of said source; means for coupling a second end connection of each of said plurality of potentiometers to a second terminal of said source; a plurality of double pole switches each of said switches being associated with two of said potentiometers and including means for completing a first electrical circuit between a first pair of switch terminals and means for completing a second electrical circuit between a second pair of switch terminals; a first output bus; a second output bus; means for coupling one of said first pair of switch terminals of each of said double pole switches to said first output bus; means for coupling one of said second pair of switch terminals of each of said double pole switches to said second output bus; means for individually coupling the other of said first pair of switch terminals of each of said double pole switches to the variable tap of the first of said potentiometers associated with said switch; means for individually coupling the other of said second pair of switch terminals of each of said double pole switches to the variable tap of the second of said potentiometers associated with said switch; an output line coupled to one of said variable reactance element terminals; switch means for selectively coupling said output line to said first output bus and said second output bus; and means coupling the other of said variable reactance element terminals to a terminal of said source.

Claim 7

A television signal frequency converter apparatus including an impedance element having a variable reactance dependent upon the magnitude of a voltage applied across two terminals thereof, electrical circuitry for tuning said apparatus comprising: a plurality of tuning potentiometers each of said potentiometers having two end connections and a variable tap; a source of d.c. potential; means for coupling one end connection of each of said plurality of potentiometers to a first terminal of said source; means for coupling a second end connection of each of said plurality of potentiometers to a second terminal of said source; a plurality of double pole switches each of said switches being associated with two of said potentiometers and including means for completing a first electrical circuit between a first pair of switch terminals and means for completing a second electrical circuit between a second pair of switch terminals; a first output bus; a second output bus; means for coupling one of said first pair of switch terminals of each of said double pole switches to said first output bus; means for coupling one of said second pair of switch terminals of each of said double pole switches to said second output bus; means for individually coupling the other of said first pair of switch terminals of each of said double pole switches to the variable tap of the first of said potentiometers associated with said switch; means for individually coupling the other of said second pair of switch terminals of each of said double pole switches to the variable tap of the second of said potentiometers associated with said switch; an output line coupled to one of said variable reactance element terminals; switch means for selectively coupling said output line to said first output bus and said second output bus; and means coupling the other of said variable reactance element terminals to a terminal of said source.

Claim 8

A converter for converting television signals from one of a plurality of input channels to a single preselected output channel, comprising in combination; a variable frequency oscillator for generating a signal having a selected frequency above any frequency within said input channels, a first mixer connected to receive signals within a selected one of said input channels and connected with said oscillator to mix said oscillator signal with said selected input channel signals, thereby raising the frequencies of signals from a selected input channel to a supervideo channel, a fixed frequency oscillator having a frequency greater than any frequency within said supervideo channel, and a second mixer connected with said fixed frequency oscillator and with said first mixer to lower the frequencies of signals within said supervideo channel to said preselected output channel, said variable frequency oscillator comprising an amplifying device, feedback means interconnecting the input and output of said amplifying device, a tuned circuit connected with said feedback for establishing the frequency of oscillation of said oscillator, said tuned circuit including varactor means, the reactive impedance of said varactor means being dependent upon the magnitude of a d.c. voltage applied thereto, and manually operable control means connected to said varactor means for applying a selected d.c. voltage thereto and comprising: a plurality of individually operable double pole switches, a first plurality of potentiometers, one for each of sAid switches, means for connecting the taps of said first plurality of potentiometers individually to a contact of a first pole of said switches, a second plurality of potentiometers connected in parallel with the first said plurality of potentiometers, means for connecting the taps of said second plurality of potentiometers individually to a contact of a second pole of each of said switches, means for applying a potential difference between the end terminals of said potentiometers, a double-throw selector switch, means for connecting a contact of said selector switch with a contact of said first pole of all of said individually operable switches, means for connecting another contact of said selector switch with a contact of said second pole of all of said individually operable switches, and means for connecting the common terminal of said selector switch with said varactor means whereby the d.c. voltage applied to said varactor means is determined by the setting of the tap of one of the potentiometers associated with an operated one of said switches.

Claim 9

A converter for converting television signals from one of a plurality of input channels to a single preselected output channel, comprising in combination; a variable frequency oscillator for generating a signal having a selected frequency above any frequency within said input channels, a first mixer connected to receive signals within a selected one of said input channels and connected with said oscillator to mix said oscillator signal with said selected input channel signals, thereby raising the frequencies of signals from a selected input channel to a supervideo channel, a fixed frequency oscillator having a frequency greater than any frequency within said supervideo channel, and a second mixer connected with said fixed frequency oscillator and with said first mixer to lower the frequencies of signals within said supervideo channel to said preselected output channel, said variable frequency oscillator comprising an amplifying device, feedback means interconnecting the input and output of said amplifying device, a tuned circuit connected with said feedback for establishing the frequency of oscillation of said oscillator, said tuned circuit including varactor means, the reactive impedance of said varactor means being dependent upon the magnitude of a d.c. voltage applied thereto, and manually operable control means connected to said varactor means for applying a selected d.c. voltage thereto and comprising: a plurality of individually operable double pole switches, a first plurality of potentiometers, one for each of sAid switches, means for connecting the taps of said first plurality of potentiometers individually to a contact of a first pole of said switches, a second plurality of potentiometers connected in parallel with the first said plurality of potentiometers, means for connecting the taps of said second plurality of potentiometers individually to a contact of a second pole of each of said switches, means for applying a potential difference between the end terminals of said potentiometers, a double-throw selector switch, means for connecting a contact of said selector switch with a contact of said first pole of all of said individually operable switches, means for connecting another contact of said selector switch with a contact of said second pole of all of said individually operable switches, and means for connecting the common terminal of said selector switch with said varactor means whereby the d.c. voltage applied to said varactor means is determined by the setting of the tap of one of the potentiometers associated with an operated one of said switches.

Claim 10

Apparatus according to claim 6, including first and second ganged fine-tuning rheostats, means for connecting one of said rheostats between a first terminal of each of said plurality of potentiometers and a source of d.c. potential, means for connecting the other rheostat between a second terminal of each of said plurality of potentiometers and a reference potential, and means for ganging said rheostats so that an increase in resistance of one of said rheostats is accompanied by a decrease in resistance of the other rheostat.