US1487108A

US1487108A - Regulating system

Info

Publication number: US1487108A
Application number: US578568A
Authority: US
Inventors: William A Knoop
Original assignee: Western Electric Co Inc
Current assignee: AT&T Corp
Priority date: 1922-07-31
Filing date: 1922-07-31
Publication date: 1924-03-18
Anticipated expiration: 1941-03-18

Description

March 1s 1924.

W. A. KNOOP REGULATING SYSTEM Filed July 31. 1922 VMM/Mw? A. Knoop Patented Mar. 18, 1924.

UNITED STATI-:s

PATENT OFFICE.

WILLIAM A. KNOOP, OF NOBTHPOBT, NEW Y'OBX, `ABSIGNOR TO WmTEBN ELEC- TBIC COIPANY, INCORPORATED, F NEW YORK, N'. Y., A CORPORATION OF NEW YORK.

BEGULATING SYSTEM.

Application mcd July'al, 1922. Serial No. 578,568.

To all whom it may concern:

Be it known that I, WILLIAM A. KNoor, a citizen of the United States, residing at East Northport, in the county of Nassau, State of New York, have invented certain new and useful Improvements in Regulating Systems, of which the following is a full, clear, concise, and exact descrlption.`

This invention relates to regulating systems, and particularly to a voltage re lating system employing an electric ischarge device.

An object of this invention is to supply a constant voltage to a load circuit inde- 15, pendent of variations in the voltage of the supply source.

Another object is to provide an electric dischar e regulator for regulating an electrical characteristic of a source of voltage or current. I l l l Another object is to obtain a substantially constant voltage across the anode and cathode electrodes of an electric discharge repeater.

Invaccordance with one form of this invention these objects are accomplished by employing a three electrode vacuum tube comprising an anode, a cathode and a control electrode which operates so that a variation in the tential impressed upon the control electro e will var to a much greater extent the space current owing between the anode and cathode electrodes. The anode and cathode are connected across the line upon which it is desired to impress constant voltage. The potential of the control electrode is made responsive to variations in the source of voltage supply in such a man ner that an undesired increase, for exam le, in' voltage, increases the space current tween the anode and cathode. By providing a resistor of suitable magnitude in series with. the source of voltage and the anode and cathode, the resulting increase yin space current will produce an increase in the IR drop in the resistance to compensate for the increase in voltage and to hold substantially constant the potential difference between the anode and cathode. The load circuit may, therefore, be connected across the anode and cathode electrodes and consequently will be supplied with a constant voltage regardless of the variations in the potential of the source.

variations in the load circuit to which it is connected.

Fig. 3 illustrates aform of this invention that does not require a constant source of potential for the control electrode of the re lator.

ig. 1 illustrates, in the lblocli: designated 5, a oad circuitl to which it is desired to sulpply constant voltage from a battery or ot ier source of otential 6. In accordance with this inventlon the leads 7 and 8 going to the load circuit .are connected b a shunt path com risin the anode 9 an cathode 10 of a t ree-e ectrode discharge device or amplifier 11. Connected also across leads .7l and 8 is a high resistance 12, an inter mediate point of which preferably through a constant source of voltage 13 is connected to the control electrode 14of the vacuum tube regulator. Resistance element 15, shown in series with the -source of voltage 6 and the anode 9 and cathode 10, is of a definite value predetermined in a manner hereinafter described.

The manner in which voltage regulation akes place mayI now be explained as folows:

If, for example, voltage of source 6 should suddenly increase over its normal value, the potential dro in resistance 12 will increase thereby ma ing less ne ative, or more positive as the case may be, t e potential o control electrode 14 with respect to cathode 10. This increase in the voltage of control electrode 14 will produce a much reater increase in the space current flowing between the anode 9 and the cathode 10. The increase in space current in tube 11 will cause an increase in the current flowing throu h resistance 15, and resistance 15 shoul therefore, have such a value that the resulting increase in the IR drop .across the termin-als of the resistance just compensates for the increase in the voltage of source 6. With such an adjustment, the voltage across the anode 9 and cathode 10 of the vacuum tube will remain constant and, consequently, the voltage supplied to asl the load circuit 5 will remain constant regardless of the changes in the source of voltage 6. The operation of the regulator for a decrease in voltage of source ma be explained in a similar manner, since suc a decrease would make the control electrode la more negative thereby decreasing to a much greater extent the space current in tube 11 and the current flowing in resistance 15 such that the decrease in the IR drop in resistance 15 is sutiicient to compensate for the decrease in voltage of source 6. This arrangement therefore supplies a constant voltage to the load circuit and will also supply a constant current thereto providing the impedance of the load is constant, and this invention is preferably used 'with a constant load impedance.

rhis regulation may he explained mathematically as follows: Ec, the potential ci the grid battery 13, should preferably have a potential equal to or slightly greater and opposite EBT, rl-'rrz Where EB is the potential of source 6; r, that portion or resistance 12 included between the control electrode and the cathode; r2 that portion of resistance 12 included between the anode and control electrode; and r3, resistance 15. rThis will result in making the total potential of the grid with respect to the ilament zero or slightly negative. Under these conditions no current will be drawn from the grid potential battery.

Assume that the device is operating and that the potential EB should rise by an amount AEE. The potential of the grid vill rise an amount Assulne that the tube is Working on practically the straight line part of its rid volt- Where Ip represents the space current and E; the grid voltage. A change in Es of DEBT! rfi-r,

will cause an increase in Ip of AEM*1 dI, rl'l'rz This increase of IP flows through T3 causing an increased RI drop equal to or solving for r3,

1 ,FMX-gr; f1 an.,

The last expression designates the value of the resistance 15 of Fig. 1 in terms of the 1value of resistance 12 and the slope of the grid voltage-space current characteristic of the vacuum tube 11.

The arrangement of Fig. 2 is similar to that of Fig. 1 in that resista-nce 20, that part of resistance 21 lieti-veen resistance 20 and adjustable contact 22, and resistance 23 correspond to resistance 15 of Fig. l. Resistance 21, however, acts as a potentiometer since by adjustment of movable contact 22 any desired constant traction o'i the voltage of source 24.- may be impressed upon the load circuit. An additional resistance 26 is provided in Fig. 2 in the shunt circuit including the anode 27 and cathode 28 of the vacuum tube regulator 29, which resistance should have a value at least as great as the effective resistance between the anode 2T and cathode 28 and may sometimes have a value several times greater. The purpose of resistance 26 is to make the grid voltage space current characteristic of the vacuum tube approximate a straight-line over a Wider vo tage range than may be obtained with the resistance omitted.

The operation of the arrangement of Fig. 2 is similar t0 that of Fig. 1 in that a variation in the volta 'of the generator or other source 24 will c ange the potential drop in resistance 30 thereby changing the potential of grid 31 and the space current between the anode and cathode in such a manner that the resulting chan e in the IR drop in resistance 20, 2l an variation in the source 24.

In the form shown in Fi 3 a battery or other source of constant vo tage for maintaining the control electrode at a negative potential is unnecessary. In this figure the potential of the grid 35 is always positive to the cathode 36 so that a. certain amount of grid current is present in the tube. The grid and cathode are connected across the output leads of generator 37 in series with a resistance 38, While the anode 39 and cathode are connected in series with a second resistance 40 and the generator. The values of the resistances should be so chosen that an increase` for example, in the voltage of source 37 will make the grid more positive thereby increasingthe space current of tube 41 and increasing the .IR drop in resistance 40 an amount sufficient to compen- 23 compensates for the lll lll

sate for the increase in source 37. The arrangement of this figure has the advantage that both the grid voltage-anode current characteristic and grid voltage-grid current characteristic curves of the tube depart from a straight line in substantially the same manner, so that the curvature of one 1s compensated for at least 1n part by the other.

The referable values for the arrangement o Fi 3 ma be obtained as follows: Let EG an IG be t ie grid voltage and grld i current, En the voltage of the generator,

Ep and Ip the anode voltage and anode c urrent, TG the resistance 38, and r, the reslstance 40.

If a change AEE takes place 1n the generator voltage,

AEG= AE,- Alon,

= AEiVroAEo Ego dIv AEs: AEG 1+ ra lace of the load. EB is then applied and p set to the desired valueA by means of varying value of resistance 15. The movable contact on resistancel 12 may then be var1ed until a minimum noise is heard in the receiver. x

It is to be understood that this invention is not limited to the specific embodiments above.

described, but as will occur to those skilled in the art, the above arrangements may besubstantially modified without departing'lnan way from the s pirit of this invention as de ned in the appended claims.

What is claimed is:

1. In combination, a source of voltage subject to variations, a load circuit, and means for sup lying said load circuit with a con-v stant vo tage, said mea-ns comprising an electric discharge device having an anode, a

vcathode and a control electrode, said load circuit being connected across said anode and cathode, means responsive to var1at1ons in a characteristic of said source for producing variations in the potential of said control electrode and a resistance connected in series'with said source, said anode and said cathode.

2. In combination, a load circuit, a source of voltage, connections for supplying said load circuit with constant voltage from said source, a vacuum tube havin an anode, a cathode and a control electrode, said anode and cathode being connected in shunt to said connections, an impedance connected across said connections, a connection from an intermediate point of said impedance to said control electrode, and an impedance in series with said first connections and located electrically between said source and said tube.

3. In combination, a vacuum tube having an anode, a cathode and a control electrode, a resistance, a series circuit connection comprising said source, said resistance, said anode and said cathode, and means responsive to changes of voltage of the said source to change the potential of said control electrode for holding substantially constant the voltage across said anode and said cathode.

4. In combination, a vacuum tube having an anode, a cathode and a control electrode, a source of voltage, and impedance, a series circuit connection comprising4 said source, said anode, said cathode and said impedance, a second impedance in shunt to said source, and a connection for including a portion of said second impedance between said control electrode and said cathode to cause said control electrode to be responsive solely to variations of said source.

5. In combination, a vacuum tube having -an anode, a cathode' and a control electrode, a source of volt-age for supplying space current to said tube, means for holding substantially constant the voltage drop across said anode and cathode, said means comp-rising a resistance in series with said source, said anode and said cathode, a second resistance in shunt to said source, and a connection from said second resistance to said controlelectrode.'

' 6. In combination, a vacuum tube having an anode, a cathode and a control electrode, a source' of volt-age'rfor supplying space current to said tube, means responsive to a voltage increase by said source for va ing the potential of said control electro e, and means responsive to the increase of space current of said tube for causing a fall of potential between said source and said tube equal to the increase of voltage of said source, whereby a substantially constant voltage is maintained across said anode and said cathode.

7. In combination, a vacuum' tube having an anode, a cathode and a control electrode, a source of voltage, and means for maintaining a substantially constant voltage across said anode and cathode, said means comprising a resistance in series with said source, saidanode and said cathode, a second resistance in shunt to said source, a connection from said resistance to said control electrode such that a portion of said second resistance and said rst resistance is included in circuit between said control in circuit between said control electrode of said second resistance being included in circuit between said contrlol electrode and said cathode, means for supplying a constant negative potential to said control electrode, said first resistance having a value determined by the slope of the control electrode voltage space current characteristic of said vacuum tube.

8. In combination, a vacuum tube having an anode, cathode and a control electrode, a source of voltage, means for maintaining a substantiallyv constant voltage across said anode and cathode, said means comprising a resistance in series with said source, said anode and said cathode, a second resistance in shunt to said source, a connection from said resistance to said control electrode such that a portion of said second resistance and said first resistance is included in circuit between said control electrode and said anode, said first named resistance having a value approximately equal to'the value of said second resistance divided by the product of said second named portion of said resistance and the slope of the control electrode voltage-space current characteristic of said tube at the point of operation.

9. In combination, a direct current source of volta e subject to variations, a load circuit, ant means for supplying constant current to said load circuit, said means comprising a vacuum tube having an anode, a cathode and a control electrode, said load circuit being connected across said anode and cathode, means responsive to variations in a characteristic of said source for producing variations in the potential o said control electrode, and a resistance connected in series with said source, said anode and said cathode.

In witness whereof, I hereunto subscribe my name this 29th day of July A. D., 1922.

WILLIAM A. KNOOP.