Dynamo ergometer

Claim 2

In a dynamo ergometer having an electrical generator means having at least d.c. output terminals; means driven by the patient to be examined for driving said generator means; a load resistance coupled to the output terminals of said generator means for absorbing the electrical energy produced by said generator means; and a control circuit means for controlling the energy absorbed by said load resistance to a value such that the physical energy transmitted by the patient to said drive means has an adjustable value which is substantially independent of the speed of rotation of said generator means; the improvement wherein said load resistance includes the series connection of a fixed resistor and a variable resistance controllable device; and wherein said control circuit means is coupled to the output terminals of said generator means and derives all of its operating power therefrom, and is connected to said controllable device to vary the resistance thereof.

Claim 3

The ergometer as defined in claim 1 wherein said generator means includes a self-excited generator.

Claim 4

The ergometer as defined in claim 1 wherein said electrical generator means comprises an a.c. generator having a rectifier circuit connected to its a.c. voltage output terminals.

Claim 5

The ergometer as defined in claim 1 wherein said electrical generator means is a d.c. voltage generator.

Claim 6

The ergometer as defined in claim 1 wherein said load resistance and said control circuit means are connected to the d.c. output terminals of said generator means; and wherein said control circuit means contains; a first means for providing a signal which is proportional to the electric energy absorbed by said load resistance; a second means for producing a signal proportional to the desired value of the electrical energy to be produced by the generator; and a control amplifier connected to the outputs of said first and second means for providing an error signal at its output dependent upon the deviation of the output signal of said first means from the output signal of said second means, the output of said control amplifier being connected to said controllable device to control the resistance thereof.

Claim 7

The ergometer as defined in claim 5 wherein said controllable device is a power transistor having its emitter-collector current path connected in series with said resistor, and its base connected to the output of said control amplifier.

Claim 8

The ergometer as defined in claim 5 wherein said electrical generator means includes a three-phase a.c. generator with three pairs of three-phase output terminals, and a separate rectifier circuit connected to each pair of said generator output terminals; and wherein there are three of said load resistances, the d.c. output terminals of each of said rectifier circuits being connected to a separate one of said load resistances.

Claim 9

The ergometer as defined in claim 7 wherein the output signal from a single one of said control circuit means is connected to and controls the controllable device in all of said three load resistances.

Claim 10

The ergometer as defined in claim 7 wherein said control circuit means includes a plurality of said first means and said control amplifiers with a different one of said first means and said control amplifiers being provided for each outpUt phase of said generator means.

Claim 11

The ergometer as defined in claim 5 wherein said means for producing a signal proportional to the energy absorbed by the load includes a multiplier circuit having a first input to which is fed a signal which is proportional to the voltage across said load resistance, and a second input to which is fed a signal corresponding to the current flowing through said load resistance.

Claim 12

The ergometer as defined in claim 5 wherein said means for producing a signal corresponding to the desired value of the electrical energy to be produced by the generator contains a first circuit arrangement for producing a constant voltage whose output is adjustable to a value corresponding to the total energy to be expended by the patient, a second circuit arrangement for producing a signal proportional to the speed of said generator, and hence to the frictional energy losses in said generator, and a summing circuit for providing an output signal equal to the difference between said speed-proportional signal and said constant voltage.

Claim 13

The ergometer as defined in claim 1 wherein said generator means is an a.c. generator having a rectifier circuit connected to its a.c. voltage output terminals; wherein said load resistance is connected to the a.c. voltage output terminals of said generator and wherein said control circuit means is connected to the d.c. voltage output terminals of said rectifier circuit.

Claim 14

The ergometer as defined in claim 12 wherein said control circuit means comprises a first circuit arrangement for producing a constant voltage whose output is adjustable to a value corresponding to the total energy to be expended by the patient, a second circuit arrangement for producing a signal proportional to the speed of said generator, and hence to the frictional energy losses in said generator, and a summing circuit for providing an output signal equal to the difference between said speed-proportional signal and said constant voltage.

Claim 15

The ergometer as defined in claim 12 wherein said controllable device contains at least one thyristor whose current flow angle is controlled by an output signal furnished by said control circuit means.

Claim 16

The ergometer as defined in claim 14 wherein said generator means includes a three-phase a.c. generator, and wherein said load resistance includes a single load resistor connected to the a.c. output terminals of said generator via a three-phase thyristor circuit.

Claim 17

The ergometer as defined in claim 13 wherein said controllable device comprises a magnetic amplifier.

Claim 18

In a dynamo ergometer having an electrical generator means having at least d.c. output terminals; means driven bY the patient to be examined for driving said generator means; a load resistance means, coupled to the output terminals of said generator means, for absorbing the electrical energy produced by said generator means; and a control circuit means for controlling the energy absorbed by said load resistance means to a value such that the physical energy transmitted by the patient to said drive means has an adjustable value which is substantially independent of the speed of rotation of said generator means; the improvement wherein said control circuit means is coupled to the output terminals of said generator means and derives all of its operating power therefrom; wherein said electrical generator means includes a three-phase a.c. generator with three pairs of three-phase output terminals, and a separate rectifier circuit connected to each pair of said generator output terminals; and wherein there are three of said load resistance means with the d.c. output terminals of each of said rectifier circuits being connected to a separate one of said load resistance means.

Claim 19

In a dynamo ergometer having an electrical generator means having at least d.c. output terminals; means driven bY the patient to be examined for driving said generator means; a load resistance means, coupled to the output terminals of said generator means, for absorbing the electrical energy produced by said generator means; and a control circuit means for controlling the energy absorbed by said load resistance means to a value such that the physical energy transmitted by the patient to said drive means has an adjustable value which is substantially independent of the speed of rotation of said generator means; the improvement wherein said control circuit means is coupled to the output terminals of said generator means and derives all of its operating power therefrom; wherein said electrical generator means includes a three-phase a.c. generator with three pairs of three-phase output terminals, and a separate rectifier circuit connected to each pair of said generator output terminals; and wherein there are three of said load resistance means with the d.c. output terminals of each of said rectifier circuits being connected to a separate one of said load resistance means.