US2521774A

US2521774A - Predetermined counter

Info

Publication number: US2521774A
Application number: US736214A
Authority: US
Inventors: Warren H Bliss
Original assignee: RCA Corp
Current assignee: RCA Corp
Priority date: 1947-03-21
Filing date: 1947-03-21
Publication date: 1950-09-12
Anticipated expiration: 1967-09-12

Description

Sept. 12, 1950 w. H. BLISS PREDETERMINED COUNTER Filed March 21, 1947 INYENTOR. Wanre 11f]. filiss ATTORNEY Patented Sept. 12, 1950 PREDETERMINED oocm'sn Warren H. .Bliss, Princeton, N. J., assignor to f America, a corporation of Radio Corporation 0 Delaware Application March 21, 1947, Serial No. 736,214

3 Claims. ((1235-92) This invention relates to control systems such as are adopted (1) to limit industrial processes to a selected interval of time, (2) to control a device for delivering a selected number of articles to be enclosed in a container, (3) to control or vary the relation between the frequencies of an input and an output potential, or (4) to exert a control efiect generally in cases where it is desired to count or measure quantities such as periods of time, numbers of objects or the like.

In many processes such as spot welding and chemical reactions it is desirable to have available a stop watch type of apparatus which may beutilized to terminate the process at the end of a predetermined time interval or to measure the time required for the completion of such processes. In other processes such as the bottling or packaging of articles, it is desirable to provide means whereby selected numbers of such articles may be automatically delivered to the containers in which they are to be sold. To avoid wear and waste of energy, and to attain high operating speeds it is sometimes desirable that the counting and measuring apparatus be automatically reset to its standby condition or cease to operate at each completion of the controlled process.

In accordance with the present invention, these results are achieved by means of a control system which includes a plurality of trigger circuits connected in groups of four each of which (1) is arranged to complete its cycle of operation in response to ten input pulses, and (2) is provided with means whereby any count of the group may be selected for the purpose of exerting a control effect. These dilferent groups or decades are connected in tandem so that one control pulse is delivered from a higher speed decade to the next lower speed decade each time such higher speed decade completes its cycle of ten counts. Thus if 0.01 second is required to complete; the cycle of the first or higher speed decade, the cycle of the second decade will be completed in 0.1 second; that of the third decade in 1 second, etc.

conduct current at a time. Current conduction is transferred fromv one to the other of the triodes in response (1) to the application of a negative pulse to the grid of a triode which is conducting, (2) to the application of a positive pulse to the grid of a triode which is not conducting or (3) to the application of a negative pulse to the lead through which the separate anode resistors are connected to the common anode resistor. In all cases, the pulses to be counted are applied to the input of the highest speed decade which represents the lower orders of, the entire count.

The selector for producing a desired control.

7 eifect in response to different numbers of pulses The trigger circuit of which the decades are constituted may be of different types. It is illustrated as including a pair of triodes each of which (1) has its anode coupled to the grid of the other through a resistor shunted by a capacitcr, (2) has its cathode grounded, (3) has bias potential applied to its grid through a separate resistor, and (4) has operating potential applied to its anode through a separate resistor and a resistor which is common to the anodes of both triodes.

With these connections, only one of the triodes applied to the input of the highest speed or lowest order. decade is illustrated as a three point switch which is moved over three series of fixed contacts which are each connected to a difierent anode of the decade through a resistor. These connections between the decade anodes and the fixed contacts of the switch are so arranged that the switch delivers a positive control potential only in response to a number of decade input pulses determined'by the setting of the switch.

The output terminals of the selector switches of the various decades are connected to a control circuit which functions to deliver a control potential only in response to the number of decade input or counting pulses which is determined by the setting of the selector switches of the different decades. In the illustrated form of the invention, this control potential is utilizedto reset the various decades to their standby condition and to produce some effect in a'circuit external to the control system itself." Obviously it may be uti-' lized to terminate the supply of input pulses to the highest speed decade if desired and to produce various other effects.

The principal object of the invention is the provision of an improved control system and method of operation whereby a control pulse is reproduced in response to any desired number of input pulses. An important object of the invention is the provision of an improved control systern which includes a minimum of parts and is simply operated to limit an operation or effect to any selected time interval. 'Another object is the provision of an improved control system which is adapted to respond to a selected number of input pulses after which it is automatically reset to its standby or zero count condition.

' The invention will be better understood from the following description considered in connection withthe accompanying drawing and its scope is indicated bytheappended claims.

The single figure of the drawing is a wiring diagram of the improved control circuit. It shows in its lower section a four decade counter, the first decade of which is shown in detail and the other decades of which are shown as boxes. At the upper left-hand section of the figure is shown the details of the selector switch for the first decade. The selector switches of the other decades are shown as boxes located above the corresponding decades. The control circuit to which all these selector switches are connected is shown at the upper mid-section of the figure. The output lead of the control circuit is connected to an output lead and a reset circuit shown at the upper right-hand section of the figure.

Input pulses are applied to the first decade through a coupling capacitor I0. This decade includes four trigger circuits VI to V4 which are connected in tandem through coupling capacitors 25, 2'! and 28. Operating potential is applied to the anodes of the tri er circuits. VI to V4 respectively through. common anode resistors 20 to 23. The anodes of the difierent trigger circuits are indicated respectively by the reference numerals II and I2, I3 and I4, I5 and I6 and I! and I8. It will be noted that (l) the anode I5 01 the trigger circuit V3 is coupled through a capacitor 62 and a resistor 63 to the right-hand grid of the trigger circuit V2 and (2) the anode ll of the trigger circuit V4 is coupled through a capacitor 60 and a resistor 6| to the right-hand grid of the trigger circuit V3. In the zero count or standby condition of the decade, current conduction is in the righthand triode of each trigger circuit as indicated by arrows adjacent the separate anode resistors.

The operating cycle of the decade is indicated by the following tabulation:

In thistabulation, thenumber of applied input pulses. is indicated by the numerals of the first column, the letter R indicates that current conduction is in the right triode of the trigger circuit, and the letter L indicates thatcurrent conduction is in the left triode ofthe trigger circuit. It will be noted that after the fourth input pulse V2 is turned back left when V3 turns left and that V3 is similarly turned left when V4 turns left.

The anodes II to I8 of the decade are connected respectively through resistors I0 to 11 tothe fixed contacts of a selector switch SI. Movable contacts 18, I9 and 80 are arranged so that each moves along a different row of these fixed contacts. By comparing the arrangement of the fixed contacts with the. above tabulation, it is easy to see that the most positive pulse is applied to the output lead 8| of the switch SI only when the number of input pulses applied to the decade corresponds to the switch position indicated by the numerals at the left-hand side of the fixed contacts.

Thus if the movable contact 18 to 80 are in the "4 position, for example, the switch output lead 8| is connected to the anodes II, I6 and I1. As shown by the tabulation, all these anodes are not conducting and are at a relatively high positive potential at the count of 4. In the same way, the lead 8| is made more positive at the proper count for any other setting of the switch SI.

The decade VI to V4 has its output coupled through a. capacitor 82 to a similar decade 83.

Subsequent decades

84 and 85 are similarly connected in tandem with the first two stages through

capacitors

86 and 81. Additional decades may be likewise connected through a capacitor 38.

The selector switch S2 is connected through a lead 89 to the output lead 8| of the selector SI and thence to the control grid of a pentode 90. The selector switches S3 and S4 of the

decades

84 and 85 are connected through leads 9| and 92 and a common lead 93 to the control rid of a pentode 94.

' Operating potential is applied from a lead 95 respectively through

resistors

95 and 91 to. the

anodes

98 and 99 of the pentodes and 94.

When a more positive potential is applied from all the selector switches SI to S4 to the grids or. the

pentodes

90 and 94, current is drawn through the

resistors

96 and 97 and the potentials of the

anodes

98 and 99 is made more negative. These anodes are connected to ground through separate resistors I09 and |0I and a common resistor I02 so that such more negative potential of the anodes is applied through a resistor I03 to the control. grid of a pentode I04. Capacitor I05 and I06 may be connected in shunt to the resistors I00 and I 0| for increasing the speed of operation.

When the grid potential of the pentode I04 is made more negative, less current is drawn through its anode resistor I01 and a positive pulse is applied to the output lead I08, and to the input lead I09 of the circuit by which the various decades are reset to their zero or standby condition.

The reset circuit includes a gas tetrode IIO which derives its operating potential from a lead II'I through a resistor H2. The cathode and control grid of the tetrode I I0 are connected respectively through a resistor H3 and a resistor M4 to a negative lead II5 through which bias potential is applied to the various grids of the decades.

Connected between the anode and cathode of the tetrode H0 in series with the output load resistor H3 is a capacitor IIG which is charged during the normal non-conducting state of the tetrode H9. When the previously mentioned positive pulse is applied to the grid of the tetrode III? through the lead I09, the tetrode becomes conductive and the capacitor is discharged through the load resistor II3. As a result, a positive pulse is applied to the reset lead II! of the various decades which are thereby put into their standby condition.

For normally setting the'bias potentials applied to the decade grids a resistor II8 may be connected in the lead 5 as indicated.

If desired th control. circuit including pentodes cutoff in response to the selected count and a positive pulse is applied from their common anode lead resistor to the leads I08 and H19.

What the invention provides is a control system which is readily adjusted to respond to any desired number of input pulses for producing a control effect and which is automatically restored to its normal standby condition when such effect has been produced.

I claim as my invention:

1. The combination of a plurality of decade counters connected in tandem and each incl'uding a plurality of trigger circuits of which each includes a pair of triode elements each having a grid, a cathode, and an anode, each of said pairs of triode elements having their grids and anodes cross-connected so that current is conducted either by one or the other of said triodes, means for applying input pulses to the lowest order decade of said plurality of decades, means for selectively deriving from the anodes of said triodes a control pulse which is of the same polarity and value for any number of said input pulses within the counting range of said decades, a reset lead for said decades, an electron discharge device having grid, cathode and anode electrodes, said reset lead being coupled to said discharge device to derive an output therefrom, a capacitor coupled between said electron discharge device anode and cathode, and means to impress said control pulse upon said electron discharge device v to discharge said capacitor through said discharge device whereby said decades are reset in their standby conditions.

2. The combination of a plurality of decade counters connected in tandem and each including a pluralityv of trigger circuits of which each includes a pair of triode elements each having a grid, a cathode, and an anode, each of said pairs of triode elements having their grids and anodes cross-connected so "that current is conducted either by one or the other of said triodes, means for applying input pulses to the lowest order decade'of said plurality of decades, means for selectively deriving from the anodes of said triodes a control pulse which is of the same polarity and value for any number of said input pulses within the counting range of said decades, a reset lead for-said decades, an electron discharge device having grid, cathode and anode electrodes, an output load for said discharge device coupled to said cathode, said reset lead being connected .to said cathode to derive an output therefrom, a

capacitor connected across said electron dis- Number charge device and said output load, and means for applying said control pulse to the control grid of said electron discharge device to discharge said capacitor through said impedance to provide a reset pulse across said output load.

The combination of a plurality of decade counters connected in tandem and each including a plurality of trigger circuits of which each includes a pair of triode elements each having a grid, a cathode, and an anode, each of said pairs of triode elements having their grids and anodes cross-connected so that current is conducted either by one or the other of said triodes, means for applying input pulses to the lowest order decade of said plurality of decades, meansincluding three-point switches each having fixed contacts connected to all the anodes of a difierent one of said decades for selectively deriving a control pulse which is of the same polarity and value for any number of said input pulses within the,

counting range of said'decades a reset lead for said decades, a gas electron discharge device having anode, cathode and grid electrodes, a capacitor, a resistor having one end connected to said cathode, said reset lead being connected to said cathode to derive an output therefrom, said condenser being connected between said discharge device anode and the other end of said resistor,

and means to impress said control pulse upon said discharge device grid to render-said discharge device conductive to discharge said condenser through said dischargedevice and to reset said decades to their standby conditions.

WARREN H. BLISS.

REFERENCES ci'rED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Miller Aug. 14, 1945 Flory Oct; 29, 1946 Morton et a1. Apr. 8, 1947 Miller June 24, 1947 FOREIGN PATENTS Country Date Great Britain Aug. 24, 1931 OTHER REFERENCES Electronics, June 1944, A Four-Tube Counter Decade by Potter, pp.- -113, 358, 360.

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