Power conditioner

Claim 2

A power conditioner for a radioisotope powered thermionic generator, comprising a parallel circuit of first generator output means, second DC-DC converter means, shunt regulator means, and control means for producing a decreasing control signal corresponding to the radionuclide decay of said radioisotope, said converter including a first series circuit having a step-up transformer means and an output load means and a second series circuit through said step-up means to said shunt regulator means to provide bias power for said shunt regulator means in response to said control signal for shunting power from said generator output means on the input side of said converter from a high to zero level from the beginning to the end of said generator operating lifetime whereby said control and shunting means efficiently control the converter input and output during the generator operating lifetime and consume zero power at the end of said generator operating lifetime.

Claim 3

The invention of claim 1 in which said control means has a threshold transistor and reference signal source in said parallel circuit acting as a differential amplifier for comparing said converter input voltage with a reference signal derived from said converter input to produce a decreasing control voltage corresponding to a decreasing power shunting from said converter input that is required to produce a desired converter input for providing constant low and high converter input and output voltages, constant converter output power, and varying converter input power.

Claim 4

The invention of claim 1 in which said shunt regulator means is a thermoelectric cooled shunting transistor which consumes decreasing power from said step-up means for providing an increasing variable resistance in response to a decreasing control signal whereby said shunting transistor is protected from overheating from the beginning to the end of said generator operating lifetime.

Claim 5

A power conditioner for a radioisotope heated thermionic generator, comprising a parallel circuit having a radioisotope heated thermionic generator, positive low voltage, output means, variable resistive shunting means for providing an increasing resistance in response to a decreasing bias for shunting said output means, and a DC-DC converter, comprising first and second switching transistors having bases, collectors and emitters connected to each other and said output means, a transformer having a first center tapped primary winding and a first center tapped secondary winding forming opposite ends connecting said bases to each other, to said center taps, and a resistor connecting said center tap of said first secondary winding to a source of potential that is negative relative to said positive output means, said first primary winding also having opposite ends connecting said collectors to each other, a second secondary winding on said transformer having a center taP connected to said positive output means, two oscillator transistors having interconnected emitters connected also to said center tap of said second secondary winding and collectors having a second primary winding connected thereto at its opposite ends, said second primary winding having a core and third and fourth secondary windings forming a second transformer, said third secondary windings for providing high voltage to a load and said fourth secondary windings and having means for biasing said shunting means to shunt said output means for maintaining a constant output from said third secondary winding, the radionuclide decay of said radioisotope producing decreasing output and a correspondingly decreased fourth secondary winding output for biasing said shunting means until said shunt of said output by said shunting means is zero.

Claim 6

A power conditioner for a radioisotope heated thermionic generator, comprising a parallel circuit having a radioisotope heated thermionic generator, positive low voltage, output means, variable resistive shunting means for providing an increasing resistance in response to a decreasing bias for shunting said output means, and a DC-DC converter, comprising first and second switching transistors having bases, collectors and emitters connected to each other and said output means, a transformer having a first center tapped primary winding and a first center tapped secondary winding forming opposite ends connecting said bases to each other, to said center taps, and a resistor connecting said center tap of said first secondary winding to a source of potential that is negative relative to said positive output means, said first primary winding also having opposite ends connecting said collectors to each other, a second secondary winding on said transformer having a center taP connected to said positive output means, two oscillator transistors having interconnected emitters connected also to said center tap of said second secondary winding and collectors having a second primary winding connected thereto at its opposite ends, said second primary winding having a core and third and fourth secondary windings forming a second transformer, said third secondary windings for providing high voltage to a load and said fourth secondary windings and having means for biasing said shunting means to shunt said output means for maintaining a constant output from said third secondary winding, the radionuclide decay of said radioisotope producing decreasing output and a correspondingly decreased fourth secondary winding output for biasing said shunting means until said shunt of said output by said shunting means is zero.

Claim 7

A power conditioner for a radioisotope heated thermionic generator, comprising a parallel circuit having a radioiosotope heated, thermionic generator, positive, low voltage, output means, a DC-DC converter means for converting said low voltage to high voltage for a load, threshold resistor means for providing a differential amplifier output for comparing a sample voltage with a reference, and thermoelectric cooled shunting transistor means acting as a variable resistor in response to the differential amplifier output for maintaining a constant generator output voltage while decreasing the available power therefrom and protecting said converter from load changes while shunting current from said output means for maintaining the desired converter output for said load during the radionuclide decay of said radioisotope.

Claim 8

A power conditioner for a radioisotope heated thermionic generator, comprising a parallel circuit having a radioiosotope heated, thermionic generator, positive, low voltage, output means, a DC-DC converter means for converting said low voltage to high voltage for a load, threshold resistor means for providing a differential amplifier output for comparing a sample voltage with a reference, and thermoelectric cooled shunting transistor means acting as a variable resistor in response to the differential amplifier output for maintaining a constant generator output voltage while decreasing the available power therefrom and protecting said converter from load changes while shunting current from said output means for maintaining the desired converter output for said load during the radionuclide decay of said radioisotope.

Claim 9

A power conditioner for a radioisotope heated thermionic generator, comprising a series circuit having a radioisotope heated, thermionic generator, low voltage, positive, first output means, a DC-DC converter rectifier, filter means, and a load, said converter having a self-starting first power switching means and an oscillator in parallel with said output means for providing pulsating DC for said rectifier filter and said load, and a shunt regulator in parallel with said output means for shunting current from said output selectively to decrease the output from said transformer, said regulator having a threshold means and reference voltage means in parallel with said output means for supplying a differential output corresponding to the difference between said output means and the desired output means voltage, and transistors in series with Peltier cooled thermocouples for shunting said current in response to said differential output whereby said output from said transformer is constant despite the decay of said radioisotope.

Claim 10

A power conditioner for a radioisotope heated thermionic generator, comprising a series circuit having a radioisotope heated, thermionic generator, low voltage, positive, first output means, a DC-DC converter rectifier, filter means, and a load, said converter having a self-starting first power switching means and an oscillator in parallel with said output means for providing pulsating DC for said rectifier filter and said load, and a shunt regulator in parallel with said output means for shunting current from said output selectively to decrease the output from said transformer, said regulator having a threshold means and reference voltage means in parallel with said output means for supplying a differential output corresponding to the difference between said output means and the desired output means voltage, and transistors in series with Peltier cooled thermocouples for shunting said current in response to said differential output whereby said output from said transformer is constant despite the decay of said radioisotope.

Claim 11

In an electrical power conditioner apparatus for supplying to a load a high constant output voltage and power at high efficiency from a constant, direct current, low voltage, radioisotope heated, thermionic generator, input source having an input power decay generator, comprising a series circuit having a dc-dc convertor for converting said low voltage direct current to pulsating direct current, a step up transformer, and a rectifier for supplying pulsating high voltage, the improvement, comprising parallel means connected to said input source for producing a low reference threshold voltage corresponding to the desired constant low voltage and comparing it with the input source voltage to produce a difference voltage and said desired constant voltage, means for converting said difference voltage to a proportional current, and Peltier cooled transistor for shunting means responsive to said proportional current for providing a variable resistance for shunting said input power in direct proportion to said radionuclide decay of said generator to maintain said desired constant low voltage input and high constant output voltage and power, at high efficiency.

Claim 12

In an electrical power conditioner apparatus for supplying to a load a high constant output voltage and power at high efficiency from a constant, direct current, low voltage, radioisotope heated, thermionic generator, input source having an input power decay generator, comprising a series circuit having a dc-dc convertor for converting said low voltage direct current to pulsating direct current, a step up transformer, and a rectifier for supplying pulsating high voltage, the improvement, comprising parallel means connected to said input source for producing a low reference threshold voltage corresponding to the desired constant low voltage and comparing it with the input source voltage to produce a difference voltage and said desired constant voltage, means for converting said difference voltage to a proportional current, and Peltier cooled transistor for shunting means responsive to said proportional current for providing a variable resistance for shunting said input power in direct proportion to said radionuclide decay of said generator to maintain said desired constant low voltage input and high constant output voltage and power, at high efficiency.