Ac-dc function generators using straight-line approximation

Claim 2

An electronic function generator for approximating a prescribed function of an input voltage by generating a plurality of straight line segments having specific gating points and slopes comprising: a plurality of segment generAtors for generating the straight line segments, the segment generators including threshold voltage sources providing threshold voltages, operational amplifier means responsive to the input voltage and threshold voltages and providing outputs, gating means connected to the operational amplifier means for gating the operational amplified means outputs at the gating points, and impedance means connected between the operational amplifier means and the gating means for determining the slopes of the segments; and summing means connected to the segment generators for combining the straight line segments to provide the prescribed function.

Claim 3

An electronic function generator as described in claim 1, in which the operational amplifier means has means for reversing the phase of the outputs at the segment gating points.

Claim 4

An electronic function generator as described in claim 2, in which the gating means includes means for detecting the phase reversal of the outputs.

Claim 5

An electronic function generator as described in claim 1, in which: the threshold voltages correspond to the segment gating points; the operational amplifier means provides outputs which reverse phase at the threshold voltages; gating means includes means for detecting the phase reversal of the outputs; and the impedance means includes gain resistors.

Claim 6

An electronic function generator as described in claim 1, additionally comprising a resistor connecting the input voltage to the summing means for determining the slope of a segment having a gating point of zero input voltage.

Claim 7

An electronic function generator as defined in claim 1, in which the summing means includes an operational amplifier.

Claim 8

An electronic function generator as described in claim 1, in which each gating means comprises: a gating device connected to the impedance means for gating the operational amplifier means output; and control means connected to the operational amplifier means and responsive to the operational amplifier means output for controlling the gating device.

Claim 9

An electronic function generator as described in claim 7, in which the gating device includes a bidirectional gating element.

Claim 10

An electronic function generator as described in claim 8, in which the bidirectional gating element comprises a field effect transistor.

Claim 11

An electronic function generator as described in claim 7 in which each control means includes: an operational amplifier connected to the operational amplifier means for receiving and amplifying the output therefrom; a reference signal source providing a reference signal; and a field effect transistor connected between the operational amplifier and the gating device and responsive to the output of the operational amplifier and the reference signal for controlling the gating device.

Claim 12

An electronic function generator as defined in claim 10, in which the summing means includes an operational amplifier.

Claim 13

An electronic function generator as described in claim 10, additionally comprising a resistor connecting the input voltage to the summing means for determining the slope of a segment having a gating point at zero input voltage.

Claim 14

An AC-DC function generator for providing a voltage that approximates a prescribed function of an input voltage by the use of a plurality of straight line segments each having a specific gating point and slope, comprising: a plurality of segment generators each for providing an output voltage that varies linearly with the input voltage when the input equals or exceeds a specific gating point, each segment generator includes a threshold voltage source providing a threshold voltage corresponding to a gating point, operational amplifier means responsive to the input and threshold voltage for providing an output voltage that varies linearly with the input voltage and is at a zero level when the input voltage equals the threshold voltage, gating means for gating the output voltage when the input vOltage equals or exceeds the threshold voltage, and impedance means connected between the operational means and the gating means for alternating the output voltage; and summing means connected to the segment generators for summing the output voltages to provide an approximation of the prescribed function.

Claim 15

An AC-DC function generator for providing a voltage that approximates a prescribed function of an input voltage by the use of a plurality of straight line segments each having a specific gating point and slope, comprising: a plurality of segment generators each for providing an output voltage that varies linearly with the input voltage when the input equals or exceeds a specific gating point, each segment generator includes a threshold voltage source providing a threshold voltage corresponding to a gating point, operational amplifier means responsive to the input and threshold voltage for providing an output voltage that varies linearly with the input voltage and is at a zero level when the input voltage equals the threshold voltage, gating means for gating the output voltage when the input vOltage equals or exceeds the threshold voltage, and impedance means connected between the operational means and the gating means for alternating the output voltage; and summing means connected to the segment generators for summing the output voltages to provide an approximation of the prescribed function.

Claim 16

A device as described in claim 13, wherein the gating means comprises: a first field effect transistor connecting the impedance means to the summing means: an operational amplified connected to the operational amplifier means for receiving the output voltage therefrom and having an output providing a signal the phase of which varies in response to the output voltage of the operational amplifier means: a second field effect transistor connecting the operational amplifier output signal to the first field effect transistor; and a reference signal source connected to the second field effect transistor and providing a reference signal thereto, said second field effect transistor being responsive to the relative phase of the reference signal and the operational amplifier output signal for passing the operational amplifier output signal to the first field effect transistor which is controlled thereby for passing the output voltage when the input voltage equals or exceeds the threshold voltage.