US2629855A - Voltage regulator system for high and low voltage regulation - Google Patents

Description

Feb. 24, 1953 O sc 2,629,855

VOLTAGE REGULATOR SYSTEM FOR HIGH AND LOW VOLTAGE REGULATION Filed Aug. 7, 1944 Elma/whom OTTO H. SOHMITT WMZZAK Patented Feb. 24, 1953 VOLTAGE REGULATOR SYSTEM FOR HIGH AND LOW VOLTAGE REGULATION Otto H. Schmitt, Port Washington, N. Y., assignor to the United States of America as represented by the Secretary of the Navy Application August 7, 1944, Serial No. 548,486

3 Claims.

This invention relates to voltage-regulator systems, and more particularly to systems for regulating the out ut voltages of power supplies capable of furnishing both low-voltage and high-voltage outputs. Such arrangements, for example, are commonly employed to energize electronic equip ents from a low-voltage source, the equipments requiring regulated low voltages to energi e the filaments of the vacuum tubes and regulated high voltages for supplying their plates. A common form of such a device is a dynamotor, which comprises a single rotating armature provided with low-voltage and high-voltage commutators. When such a device is used, it is common practice to energize the filaments of the associated electronic equipments from the same source which is used to drive the low-voltage or motor portion of the dynamotor. The high-voltage or generator portion of the dynamotor in turn furnishes power suitable for the plate circuits of the vacuum tubes in the electronic equipments.

In accordance with the present invention, it is proposed to regulate the low voltage which is supplied to such a dynamotor in response to fluctuations in the high-voltage output of the dynamotor. By means of a simple electronic circuit, relatively small fluctuations in this output voltage may be utilized to provide an extremely efiective correction to the low voltage. This amplification of the control arrangement, in combination with the large inertia of the rotating armature of the dynamotor, provides a very satisfactory degree of voltage regulation.

As an additional feature of the invention, the regulated low voltage appearing at the terminals of the motor portion of the dynamotor may also be utilized to energize the filaments of the vacuum tubes of associated electronic equipments. Thus a system which is primarily adapted for providing a regulated high-voltage supply additionally provides a very useful regulated low-voltage between terminals I and 2. Resistor 3 is shunted by normally closed contacts 5 and I of relay 8. The winding of this relay is in turn connected,

in series with nor ally open contacts 9 and III of relav i I, across terminals l and 2.

Generator :portion 12 of dynamotor 5 supplies, throu h serie choke cm'l i3. a network comprising resistor l4 and voltage-regulator tube [5 in series. The latter network is shunted by potentiometer l6 and by capacitor I1, and its terminals are connected to output terminals i8 and I9, as indicated. The winding of relay l l is connected, in series with vacuumtube 20, across resi tor M. The grid of vacuum tube 20 is connected throu h series resistor 2| to the movable arm of potentiometer I6.

The direct-current source of power connected to input terminals l and 2 drives dynamotor 5, producing a high direct-current voltage between terminals [8 and I9. Due to the operation of voltage-regulator tube I5, the cathode of vacuum tube 2!) is maintained at a substantially fixed potential with respect to terminal l9. Potentiometer I6 permits the grid potential of vacuum tube 20 with respect to that of its cathode to be adjusted to a desired value. A change in the high voltage at terminals l8 and 19 will, however, produce a change in the grid-cathode potential applied to vacuum tube 20, and hence in its plate current.

The operation will be better understood by considering three conditions, two of which are hypothetical. The first condition is that in which the voltage applied to terminals I and 2 is below the normal operating range. Under this condition, the potential of the grid of vacuum tube 20 with respect to its cathode is sufficiently negative that the plate current of this tube is not large enough to energize relay II. Since relay H is normally open, relay 8 remains in its normally closed state, and resistor 3 is bypassed. Under this condition, the full voltage which is applied to terminals l and 2 appears at the terminals of the motor portion 4 of dynamotor 5.

The second hypothetical condition of operation occurs when the voltage applied to terminals I and 2 exceeds the normal operating range. Under this condition, the potential of the grid of vacuum tube 20 with respect to its cathode is such that an appreciable plate current flows, closing relay II and opening relay 8. This chain of events introduces into the input circuit resistor 3, thus lowering the voltage which appears at the terminals of motor portion 4 of dynamotor 5.

The third and only condition realized in practice is when the voltage applied to terminals l and 2 falls within the operating range. Under this condition of operation, there is a continuous shift back and forth between the first and second conditions mentioned above, so that relay 8 alternately opens and closes, the length of time it remains in each position depending upon whether the applied voltage is near the low end or the high end of the operating range. It will be understood that generator portion [2 of dynamotor 5 continues to generate a high-voltage output even when motor portion 4 is not being fully energized, since the dynamotor armature continues to rotate without substantial loss of speed for some time after the input voltage is decreased. This inertia of the dynamotor armature, in combination with the effective amplification of control realized by the use of vacuum tube 20 and its associated relays, provides a very close regulation of the high output voltage in spite of wide variations, within the operating range, of the applied input voltage.

If the voltage-regulator system is used in con.- junction with electronic equipments which employ vacuum tubes, the regulated low voltage which appears at the motor terminals of dynamotor, 5 may advantageously be also utilized. to energizev the filaments of such vacuum tubes. Terminals 22- and 23 are provided for this purpose. It will be apparent that, when the system is operating with relay 8 open and hence with resistor 3 in circuit with the source of input power, motor portion 4 of dynamotor 5 will tend to function as a generator. Because of this, the voltage appearing between terminals 22 and 23 will tend to remain substantially constant regardless of whether or not resistor 3 is in the circuit. Such provision of a closely regulated low voltage, in addition to the provision of regulated high voltage, is one of the features of the present invention.

The circuit constants and tube types may be varied and it is understood that various obvious elements may be substituted without departing from the scope of the invention as claimed.

What is claimed is:

1..In a system for delivering regulated D.-C. voltage from an unstable, D.-C. voltage source comprising the combination of a D.-C. motor and a resistor connectedinseries for connection across said source. an intermittent shunt across said resistor, voltage generating means driven by said motor, and comparing means for operating said shunt variably according to the deviation of the generated voltage from a reference voltage standard, whereby regulated D.-C. voltage may be obtained at the motor terminals.

2. Ina system for delivering regulated low voltage direct current and high voltage direct current from an unstable low voltage direct current source, the combination of a resistor and a direct-current motor in series for connection to said source, means driven by said direct-current motor for generating direct current at high voltage, a bridge including a fixed-voltage arm connected as a load on said high voltage generator, and means, including an amplifier vacuum tube energized by the unbalance voltage of said bridge, for intermittently shunting said resistor, the generator action of said motor subsequent to a shunted-resistor interval acting to maintain regulated direct-current voltage across the motor terminals and to regulate the high voltage delivered.

3. In a system for delivering regulated low voltage direct current and high voltage direct current from an unstable low voltage direct current source, the combination of a first resistor and a direct current motor in series for connection to said source, a first relay having normally closed contacts connected across said first resistor, generator means driven by said direct current motor for generating direct current at high voltage, a potentiometer having a movable arm and connected across said generator means, a second resistor and voltage regulator tube connected in series across said generator means, an electron discharge tube having an anode, control grid, and cathode, said cathode being operatively connected to the junction between said second resistor. and voltage regulator tube, said grid being operatively connected to the arm of said potentiometer, a second relay having a winding and normally open contacts, said winding being operatively connected between said anode and. the high voltage terminal of said generator means, circuit means connecting the contacts of said second relay to control the energization of the-first relay thereby providing an arrangement whereby, when the high voltage output of the generator means attains at least a predetermined value, the contacts of the first relay areopened and the first resistor effectively connected in series with the motor.

' OTTO H. SCHMITT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,101,938 Kinton June 30, 1914 1,531,872 OHa'gan Mar. 31, 1925

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