US2474269A

US2474269A - Power supply regulator system

Info

Publication number: US2474269A
Application number: US643406A
Authority: US
Inventors: Martinez Clement
Original assignee: Standard Telephone and Cables PLC
Current assignee: STC PLC; Federal Telephone and Radio Corp
Priority date: 1946-01-25
Filing date: 1946-01-25
Publication date: 1949-06-28
Anticipated expiration: 1966-06-28

Description

June 28, 1949. c. MARTINEZ POWER SUPPLY REGULATOR SYSTEM Filed Jan 25, 1946 PRIMARY "l POWER SUPPLY E m D O H N T A M M I- E o D m M m w. T R R G R R E L E m m m N m w 3 5 L H T H (I. l P R N T. m m a w w m .7 v m a c 4 t.

TIME FIG. 2

A Tron/wry Patented June 28, 1949 j,;srA'ras PATENT OFFICE to voltage regulator sys- In certain'-applic'ations of the radio art direct current" energizing voltages are required in the regionot 300to'700' volts. Under certain conditions the 'requireme'nts are for avery stable and constant supply atsuch voltages inspite of comparatively' large fluctuations imposed on the supply due to the nature of the load. I It isan object of the present invention to provide an electronic voltage regulator for the purpose stated which substantially eliminates all undesirable deviations from a given voltage. Itis 'another objector the invention to provide-an electronic voltageregulating circuit of the variable resistor tube type for a full wave rectifying power supply.

It is still a further object to provide a regulator circuit of the type referredto wherein the voltage "controlling resistor tube is controlled by a pentode amplifienthe output Voltage of which is modulated'by output voltages of the circuit and which in addition is provided with circuit elements to cause the screengrid thereof to function as an additional control grid.

Still anotherobject is to provide a voltage regulator circuit ofthe type-referred to which provides subsantiallyicomplet'e compensation for'undesirable voltage fluctuations of the output voltage. a

In. accordance'with the invention,.I provide in connection with the output circuit of a fully rectified power supply a voltage regulati g circuit wherein the main regulator function isexercised H by a variable resistor tube. The control voltage for the saidtresistor tube is supplied bya pentode amplifier, the control grid of which receives a modulating voltage from the regulator output circuit as a given fraction of the output voltage available thereacross. 'At the same time the screen grid ofvthe said amplifier is acting as an additional control grid by receiving a given proportion of the unregulatedvoltage and by having its phase compensated to such an extent that the combined action of :the screen and control grids have the eilfect of :producing a voltage in the pentode platecircuit -whichwill influence the conductivity ot theresistor tube in such a way as to substantially completely compensate for fair- 1y largevoltage' in the supply 'circuitgfluctuations and to thus assure a. constant voltage output.

These and-other features and" objects of the inventionwill become more apparent upon conrowan SUPPLY REGULATOR SYSTEM Cl'ernent Martinez, New York, N. Y., aaslgnor to 1 a; Federal Telephone and Radio Corporation, New

; York, N. Y.,,a corporation of Delaware v applicationlanuary25,.195,,SerinlNo. 643,406 mins. (Cl.11323 sideration of the following detailed description to be read in connection with the accompanying drawings in which:

Fig. 1 is a diagrammatic representation in schematic form of a voltage regulator circuit in accordance with my invention; and

Fig. 2 is a series of graphical representations of the voltage relations of various circuit elements of Fig. 1.

Referring now to the circuit diagram, a primary source of rectified voltage is indicated at l, the unregulated direct current voltage being available at its output terminals 2 and 3 which feed into an output impedance represented by a resistance 4. The voltage output across the resistance 4 is obtained at output terminals 5 and 8 of the regulator circuit. The regulation of the voltage ultimately available across 5 and 6 is obtained by means of a triode I which has an anode 8 connected to one side of the resistance 4, and a cathode 9 providing the output voltage for terminal 5. The regulated voltage output circuit also includes adjustable resistances H], H and I2 connected in series across the two terminals 5 and 6. The triode 1 also includes a control grid l3 which receives a controlling voltage from an anode H of a pentode amplifier IS. The amplifier I5 is utilized for amplifying the voltage fluctuations in the output circuit between terminals 5 and 6 by having applied to control grid 16 thereof a control voltage by means of a suitable tap ll of the resistance I I, whereby such control voltage represents a given fraction of the total output voltage. The anode potential for the amplifier I5 is obtained from the power supply I over resistances l8 and I9, a bypass condenser 20 being provided to the ground line. The amplifier l5 includes a suppressor grid 2| and a cathode 22 which are connected together and are subject to a biasing potential in respect to the grounded side of the circuit which is regulated by means of a glow discharge type regulator tube 23. A connection is provided from the positive side of the glow discharge tube to the positive terminal 5 over a dropping resistance 24 and to the tap ll through a blocking condenser 25. The amplifier l5 also includes a screen grid 26 which is subjected to the controlling action of the unregulated voltage available across the resistance 4 over a dropping resistance 21. By havthose exercised by the control grid II. A connection to ground for the screen grid circuit is provided through a resistance 30.

Thus, for instance, if a positive variation occurs in the supply circuit including the resistor tube I, a portion of this voltage variation, according to the proportion of the value of the resistances between the terminal and the tap II to the value of the resistances between the tap l1 and the terminal 6, will be applied to the control grid ii of the amplifier l5 to cause it to become more conductive to generate a proportionate negative potential in the anode circuit ll thereof which is applied to the control grid l3. This in turn increases the resistance of the tube 1 to produce a greater voltage drop in the resistor tube circuit to conteract the original positive variation. In addition, the resistances 21 and 28 are proportioned in such a way, that with the addition of the condenser 29 in the screen grid circuit, the screen grid 26 also acts as a control grid, being subject to a portion of the unregulated voltage, whereby the effect of the circuit as a whole is increased to such an extent as to produce a substantially completely compensated, that is constant, voltage across the terminals 5 and 6.

In order to make the functions and relationships of the various circuit elements somewhat clearer, a reference to Fig. 2 will be made. In graph a an imaginary fluctuation of the power supply voltage of a sinusoidal form has been indicated, as might be encountered in the anode circuit of the resistor tube 1. In order to conteract this undesirable fluctuation, the resuiting compensatory control voltage available in the anode circuit H of the amplifier I5 should be substantially, as shown in graph 0, that is, if

translated to a common reference, would be equal and opposite in sign to the fluctuations of graph a. This compensation would produce the desired steady output in the cathode circuit 9 of the resistor tube 1 as shown in graph b. The control voltage in respect to the control grid l6 produces an efiect thereon which is indicated in e showing the resulting deviation from the normal as being in phase with the ordinary undesirable fluctuation as shown in graph a. The efiect of the fluctuation on the screen grid is indicated in graph d where the wave form shown is also representative of the deviation from the normal, rather than indicating an absolute voltage condition. The constant voltage shown in graph f is that available in the cathode circuit 22 of the amplifier l 5 due to the action of the voltage regulator 23. The presence of the condenser 29 has the effect of adjusting the phase relationship of the screen grid potential in respect to that of the anode circuit and therefore to that of the original fluctuations of graph a. Thus, in conjunction with the proper proportion of the resistances 21 and 28, acomplete compensation is achieved by means of the additional control action obtained from the screen grid as described. The suitability of the relative proportion of the two resistances of the screen grid circuit is determined by the completeness with which any undesirable fluctuations are compensated by the amplifier i5 and the resistor tube I3 in view of the inherent characteristics of these two tubes.

I have found that the circuit described is particularly useful where a steady direct current voltage is required under conditions ordinarily producing large fluctuations. and that it is quite 4 practical up to about 700 volts output, one such use being the replacement of a B battery eliminator.

While the above is a descriptitn of the winciples of this invention in connection with specific apparatus, it is to be clearly understood that i grid and a cathode in said supply circuit for regulating the voltage therein; a control amplifier tube having an anode, a screen grid, a. control grid and a cathode, bridged with a series resistance across said supply circuit, means for applying the anode circuit voltage of said amplifier to said resistor tube grid, means for applying to said control grid a proportion of the voltage across said output circuit comprising a resistance thereacross, an impedance network comprising a resistance and a condenser across said supply circuit for supplying therefrom control voltage to said amplifier screen grid and cathode and suitable phase correction to said screen grid respecting said cathode, whereby said screen grid acts as an additional control and substantially complete compensation is obtained for a range of voltage fluctuations.

2. A regulator circuit for use with a unidirectional voltage source having a supply circuit and an output circuit comprising a resistor tube having an anode, a grid and a cathode in said supply circuit for regulating the voltage in said output circuit; a pentode amplifier having an anode, a screen grid, a control grid and a cathode connected across said supply circuit; means for applying the anode circuit voltage of said amplifier to said resistor tube grid; resistance means connected across said output circuit; means for obtaining a given proportion 01 the output voltage across said resistance means connected to said control grid; a resistance capacitance network across said voltage supply circuit for apportioning the available voltage as between the screen grid, the amplifier cathode and ground; the capacitance of said network comprising a phase correcting capacitor between said screen grid and said cathode; and a voltage regulator in the cathode to ground circuit of said amplifier, whereby said screen grid acts as an additional control and substantially complete compensation is obtained for a range of voltage fluctuations.

CLEMENT MARTINEZ.

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

UNITED STATES PATENTS Number Name Date 2,219,195 Norgaard Oct. 22, 1940 2,416,922 Irish Mar. 4, 1947 OTHER REFERENCES Publication entitled QST, August 1937, pp. 14-17, inclusive.

Voltage Regulated Power Supplies from "Proceedings of I. R. E.," vol. 31, No. 2, February 1943, p. 47.