Position sensor

Claim 2

A position-sensing circuit for use with a movable element having at least a conductive portion and comprising in combination: an elongated distributed resistance having a surface parallel to and facing the plane of movement of said conductive portion and providing a capacitive coupling thereto having a constant capacitive impedance; a signal oscillator producing a balanced substantially constant oscillating signal and having first and second output terminals; said first output terminal being coupled to said conductive portion; diode rectifier means coupled between said second output terminal and said distributed resistance; and means connected across said rectifier means for developing a position signal, said signal developing means including filtering means capable of providing a substantially DC output.

Claim 3

The circuit of claim 1, said rectifier means comprising first and second rectifiers oppositely poled with respect to said second output terminal and each coupled between said second output terminal and one end of the distributed resistance.

Claim 4

The circuit of claim 2, said position signal developing means including resistance means connected across the ends of said distributed resistance.

Claim 5

The circuit of claim 3 said resistance means comprising first and second resistances connected in series, and an output terminal coupled to the point between said first and second resistances.

Claim 6

The circuit of claim 1, said oscillating signal being an RF signal.

Claim 7

A position-sensing circuit for sensing the position of a galvanometer-driven movable element, said circuit comprising a source of RF oscillating signals, said source having two output terminals, a distributed resistance disposed along and spaced from the path of movement of the movable element and being constructed and arranged so that said element is capacitively coupled by a uniform capacitive impedance to a region on said resistance dependent on the position of said element, one of said signal source output terminals being connected to said movable element, a first diode rectifier having an anode connected to one end of said distributed resistance and a cathode connected to the other said signal source output terminal, a second diode rectifier having a cathode connected the other end of said distributed resistance and an anode connected to said other signal source output terminal, a pair of resistors connected in series with one another across the ends of said distributed resistance, an output signal terminal coupled to the junction of said two resistors, and filter capacitor means coupled to said output signal terminal, said filter capacitor means having a value in relation to the frequency of oscillation of said source such that a substantially DC signal appears at said output signal terminal.

Claim 8

A position-sensing circuit for sensing the position of a galvanometer-driven movable element, said circuit comprising a source of RF oscillating signals, said source having two output terminals, a distributed resistance disposed along and spaced from the path of movement of the movable element and being constructed and arranged so that said element is capacitively coupled by a uniform capacitive impedance to a region on said resistance dependent on the position of said element, one of said signal source output terminals being connected to said movable element, a first diode rectifier having an anode connected to one end of said distributed resistance and a cathode connected to the other said signal source output terminal, a second diode rectifier having a cathode connected the other end of said distributed resistance and an anode connected to said other signal source output terminal, a pair of resistors connected in series with one another across the ends of said distributed resistance, an output signal terminal coupled to the junction of said two resistors, and filter capacitor means coupled to said output signal terminal, said filter capacitor means having a value in relation to the frequency of oscillation of said source such that a substantially DC signal appears at said output signal terminal.

Claim 9

The circuit of claim 6, said filter capacitor means comprising inherent distributed capacitance of said circuit.

Claim 10

The circuit of claim 6, ground reference potential being connected to said one signal source output terminal.

Claim 11

The circuit of claim 6, ground reference potential being connected to said other signal source output terminal.