Bidirectional waveform generator with switchable input

Claim 2

A bidirectional waveform generator comprising first and second voltage sources, electrical energy storage means, switch means for energizing said storage means from said first or second voltage sources alternatively, comparator means for comparing the energy stored in said storage means with that one of said voltage sources from which the storage means is energized at a given instant, means responsive to said comparator means for operating said switch means, whereby said switch means is cyclically operated between said first and second voltage sources and said storage means is cyclically energized from said voltage sources in alternation, modulating means for varying at least one of said storage or comparator means to vary duration of the period of said cyclic switch operation, said storage means comprising an amplifier, a first impedance connected between an input of the amplifier and said switch means, and a second impedance connected between the output of said amplifier and said input thereof, said comparator means comprising a network of impedances including impedances connected to the output of said amplifier and to the output of said switch means, said modulating means comprising a second amplifier having an input from the output of said switch means, means responsive to an information signal to be modulated upon the waveform of said generator for modulating the gain of said second amplifier, and means for feeding the output of said second amplifier as a third input to said comparator means.

Claim 3

A bidirectional waveform generator comprising: first and second voltage sources, electrical energy storage means, switch means for energizing said storage means from said first or second voltage sources alternatively, comparator means for comparing the energy stored in said storage means with that one of said voltage sources from which the storage means is energized at a given instant, means responsive to said comparator means for operating said switch means, whereby said switch means is cyclically operated between said first and second voltage sources and said storage means is cyclically energized from said voltage sources in alternation, modulating means for varying at least one of said storage or comparator means to vary duration of the period of said cyclic switch operation, said storage means comprising an amplifier, a first impedance connected between an input of the amplifier and said switch means, and a second impedance connected between the output of said amplifier and said input thereof, said comparator means comprising a network of impedances including impedances connected to the output of said amplifier and to the output of said switch means, said modulating means comprising a second switch means having a second switch output connected to provide additional input to said comparator means and operable to connect said second switch output to first and second points of input potential, the values of which represent information to be modulated upon the waveform of said apparatus, and means for operating said second switch means in synchronism with said first switch means.

Claim 4

A bidirectional waveform generator comprising: first and second voltage sources, electrical energy storage means, switch means for energizing said storage means from said first or second voltage sources alternatively, comparator means for comparing the energy stored in said storage means with that one of said voltage sources from which the storage means is energized at a given instant, means responsive to said comparator means for operating said switch means, whereby said switch means is cyclically operated between said first and second voltage sources and said storage means is cyclically energized from said voltage sources in alternation, modulating means for varying at least one of said storage or comparator means to vary duration of the period of said cyclic switch operation, said storage means comprising an amplifier, a first impedance connected between an input of the amplifier and said switch means, and a second impedance connected between the output of said amplifier and said input thereof, said comparator means comprising a network of impedances including impedances connected to the output of said amplifier and to the output of said switch means, said modulating means comprising a second switch means having a second switch output connected to provide additional input to said comparator means and operable to connect said second switch output to first and second points of input potential, the values of which represent information to be modulated upon the waveform of said apparatus, and means for operating said second switch means in synchronism with said first switch means.

Claim 5

The apparatus of claim 2 including a bridge circuit having at least one leg thereof adapted to vary in accordance with a condition to be sensed, said bridge circuit having first and second energizing terminals connected to said first and second voltage sources, respectively, and having first and second bridge output terminals, said first and second bridge output terminals being connected to said first and second points of input potential.

Claim 6

The apparatus of claim 3 including a high gain operational amplifier connected between the output of said second switch and an input of said comparator means.

Claim 7

A bidirectional waveform generator comprising: a first amplifier having an output and an input, a first impedance connected with said input, first and second reference voltage sources, switch means having an output, and first and second inputs connected to said voltage sources, respectively, said switch means adapted to be operated between first and second states wherein it feeds a current through said first impedance to said amplifier input from said first and second switch means inputs, a second impedance connected between said amplifier input and output, at least one of said impedances being a reactive impedance, comparator means responsive to said amplifier output and to said switch means output for providing a trigger signal when said amplifier output attains a predetermined relation with respect to said switch means output, and means responsive to said trigger signal for operating said switch means from one of said states to the other of said states, whereby when said switch means is in said one state, current is fed to the amplifier input through said first impedance from said first switch means input and from said first voltage source to cause said amplifier output to vary until it reaches a predetermined relation with respect to said switch means output, and whereby when said predetermined relation is reached, said switch means is operated to the second state thereof to feed a current to said amplifier input through said first impedance from the second switch means input and from the second voltage source, to provide a continuously fluctuating bidirectional output signal from at least one of said amplifier and switch means outputs, modulating means responsive to an information signal for varying the period of said bidirectional fluctuating signal, said comparator means having a third input, and said modulating means comprising means responsive to said information signal for providing a modulating signal to the third input of said comparator.

Claim 8

A bidirectional waveform generator comprising: a first amplifier having an output and an input, a first impedance connected with said input, first and second reference voltage sources, switch means having an output, and first and second inputs connected to said voltage sources, respectively, said switch means adapted to be operated between first and second states wherein it feeds a current through said first impedance to said amplifier input from said first and second switch means inputs, a second impedance connected between said amplifier input and output, at least one of said impedances being a reactive impedance, comparator means responsive to said amplifier output and to said switch means output for providing a trigger signal when said amplifier output attains a predetermined relation with respect to said switch means output, and means responsive to said trigger signal for operating said switch means from one of said states to the other of said states, whereby when said switch means is in said one state, current is fed to the amplifier input through said first impedance from said first switch means input and from said first voltage source to cause said amplifier output to vary until it reaches a predetermined relation with respect to said switch means output, and whereby when said predetermined relation is reached, said switch means is operated to the second state thereof to feed a current to said amplifier input through said first impedance from the second switch means input and from the second voltage source, to provide a continuously fluctuating bidirectional output signal from at least one of said amplifier and switch means outputs, modulating means responsive to an information signal for varying the period of said bidirectional fluctuating signal, said comparator means having a third input, and said modulating means comprising means responsive to said information signal for providing a modulating signal to the third input of said comparator.

Claim 9

The apparatus of claim 5 wherein said first and second voltage sources are of mutually equal magnitude but opposite polarity, and wherein means are provided to switch polarity of said modulating signal in synchronism with operation of said switch means.

Claim 10

A bidirectional waveform generating circuit comprising: a first amplifier having an input and an output, a first resistor having one side thereof connected to said amplifier input, a capacitor connected between said amplifier input and output, a second resistor having one side connected to said amplifier output, a third resistor having one side connected to the other side of said first resistor and having the other side thereof connected to the other side of said second resistor, a comparator amplifier having an input connected to the junction between said second and third resistors and having an output, a first source of positive potential, a second source of negative potential, a first switching transistor connected between said source of positive potential and said other side of said first resistor, a second switching transistor connected between said source of negative potential and said other side of said first resistor, said first and second switching transistors having controlling inputs connected to the bases thereof, and switch driving means connected between the output of said comparator amplifier and said controlling inputs of said switching transistors to effect mutually exclusive operation Of said switching transistors in response to a given output of said comparator amplifier.

Claim 11

A bidirectional waveform generating circuit comprising: a first amplifier having an input and an output, a first resistor having one side thereof connected to said amplifier input, a capacitor connected between said amplifier input and output, a second resistor having one side connected to said amplifier output, a third resistor having one side connected to the other side of said first resistor and having the other side thereof connected to the other side of said second resistor, a comparator amplifier having an input connected to the junction between said second and third resistors and having an output, a first source of positive potential, a second source of negative potential, a first switching transistor connected between said source of positive potential and said other side of said first resistor, a second switching transistor connected between said source of negative potential and said other side of said first resistor, said first and second switching transistors having controlling inputs connected to the bases thereof, and switch driving means connected between the output of said comparator amplifier and said controlling inputs of said switching transistors to effect mutually exclusive operation Of said switching transistors in response to a given output of said comparator amplifier.

Claim 12

The apparatus of claim 7 wherein said switching transistors are of opposite polarity types having output electrodes connected together and to said other side of said first resistor and having input electrodes connected to said positive and negative voltage sources respectively, whereby a first output signal from said comparator amplifier output saturates said first switching transistor and cuts off said second transistor and a second output from said comparator amplifier saturates said second transistor and cuts off said first transistor.

Claim 13

The apparatus of claim 7 including a fourth resistor having one side thereof connected to the junction of said second and third resistors and the other side thereof adapted to receive an input signal to be modulated upon the output waveform of said apparatus.

Claim 14

The apparatus of claim 9 including a modulating amplifier having an output connected to the other side of said fourth resistor and having an input connected to be switched in synchronism with the switching operation of said first and second switching transistors, and means responsive to information to be modulated upon the output waveform of said apparatus for modifying the gain of said modulating amplifier.

Claim 15

The apparatus of claim 7 including a fourth resistor having one side connected to the junction of said second and third resistors, a modulating amplifier having an output connected to the other side of the fourth resistor and having an input, a second switching circuit having an output connected to the input of said modulating amplifier and having first and second input terminals adapted to receive an information signal to be modulated upon the output waveform of said apparatus, and means responsive to the output of said comparator amplifier for operating said second switching device in synchronism with said first and second switching transistors.

Claim 16

The apparatus of claim 11 including a bridge circuit adapted to sense a condition to be modulated upon the output signal of said apparatus, means for energizing said bridged circuit from said first and second voltage sources respectively, said bridge circuit having first and second output terminals connected to said first and second input terminals of said second switching device.