Sensing and tracking apparatus

Claim 2

Sensing apparatus, comprising: a radiation responsive, variable impedance detector element; biasing means coupled to said element for providing a pair of alternating current bias signals through said element, said bias signals being in phase quadrature; output means coupled to said element for providing an output signal indicative of position of a remote radiation source; and balancing means coupled to said bias means and said output means for each said bias signal and including a variable reference voltage level to balance said quadrature and output signals with respect to said reference level at a plurality of selected rates.

Claim 3

Sensing apparatus, comprising: a radiation responsive, variable impedance detector element; biasing means coupled to said element for providing a pair of alternating current bias signals through said element, said bias signals being in phase quadrature; output means coupled to said element for providing an output signal indicative of position of a remote radiation source; primary balancing means coupled to said bias means between said element and said biasing means for each said bias signal and including a variable reference voltage level to balance said quadrature and output signals with respect to said reference level; and secondary balancing means coupled between said output means and said primary balancing means to said variable voltage control for balancing said quadrature and output signals with respect to said reference level at a slower rate than said primary balancing means.

Claim 4

Sensing apparatus, comprising: a radiation responsive, variable impedance detector element; biasing means coupled to said element for providing a pair of alternating current bias signals through said element, said bias signals being in phase quadrature; output means coupled to said element for providing an output signal indicative of position of a remote radiation source; primary balancing means coupled to said bias means between said element and said biasing means for each said bias signal and including a variable reference voltage level to balance said quadrature and output signals with respect to said reference level; and secondary balancing means coupled between said output means and said primary balancing means to said variable voltage control for balancing said quadrature and output signals with respect to said reference level at a slower rate than said primary balancing means.

Claim 5

The sensing apparatus of claim 1, wherein: said balancing means has a feedback means, including integrator means, coupling said element, said bias means, and said output means.

Claim 6

The sensing apparatus of claim 3, wherein: said detector element includes a bridge circuit; and said balancing means includes primary balancing means coupled between said bias means and said element for initially balancing said bias and output signals with respect to said reference level to provide a null signal output when no received signal is present, said feedback means providing a feedback signal for further balancing said bias and output signals only in response to relatively slowly varying signals while passing relatively fast signals.

Claim 7

The sensing apparatus of claim 3, wherein: said feedback means includes a horizontal resolver, a horizontal integrator, a vertical resolver and a vertical integrator to enable said output means to provide an output signal indicative of position of the source of a received signal.

Claim 8

The sensing apparatus of claim 3, wherein: said feedback means includes a vertical signal channel having an operational amplifier and a horizontal signal channel having an operational amplifier.

Claim 9

The sensing apparatus of claim 1, wherein: said output means includes vertical and horizontal drive means for positioning said detector element in accordance with the position of a source of received signals.