US2519184A - Control system - Google Patents

Description

Aug. 15, 1950 E. GROSDOFF 2,

CONTROL SYSTEM Filed April 5, 1946 4 Sheets-Sheet *1 Ez'y. I

INVENTOR. IBDR EfiRusnuFF flitorney A 15, 1950 I. E. GROSDOFF 2,519,184

CONTROL SYSTEM Filed April 5, 19-46 4 Sheets-$heet 2 &

INVENTOR. I IEuR-E. fiRusnuFF BY QQML flitorfley F F 4 4 .0 V R w t m Le w 0 n w h Eu 6 VR r 5 S m 2 a E O 4 SRSQ M B P mm ww Rm m m Aug. 15, 1950 Filed Aprll 5, 1946 Patented Aug. 15, 1950 CONTROL SYSTEM Igor E. Grosdoif, Princeton,

N. J., assignor to Radio Corporation of America, a corporation of Delaware Application April 5, 1946, Serial N 0. 659,704

2 Claims.

This invention relates to control. systems such as are adapted (l) to limit industrial processes to a selected interval or time, (2) to control a device for delivering a selected number of articles to be enclosed in a container or package, or (3) to exert a control eiiect 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 be utilized to terminate the process at the end of a predetermined interval of time. In other processes such as the bottling or packaging of articles, it is desirable to have available means whereby selected numbers of such articles may be delivered to the containers in which they are to be sold. To avoid wear and waste of energy, it is sometimes desirable that the counting and measuring apparatus cease to operate when the controlled process is completed.

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 each of which (1) is arranged to register a count of ten, and (2) is provided with means whereby any count of the group may be selected for the purpose of exertin a control effect. These difierent groups or decades are connected together so that one negative pulse is delivered from a lower decade to the next higher decade each time such lower decade completes its cycle of ten. Thus if 6.01 second is required to complete the cycle of the first or lowest decade, the cycle of the second decade will be completed in 0.1 second and that of the third decade will be completed in 1.6 second.

The trigger circuits of the different decades are of the type including a pair of triodes each which (1) has its anode coupled to the grid of the other through a resistor shunted by a capacitor, (2) has its cathode grounded, (3) has bias potential applied to its grid through a separate resistor, and (-i) has operating potential applied to its anode either through a separate resistor or through a separate resistor and a resistor which is common to the anodes of the two electron discharge devices. Under these conditions, only one of the triodes conducts current at a time, and current conduction is transferred from one of the triodes to the other in response (1) to the application of a negative pulse to the grid of a triode which is conducting current, (2) to the application of a positive pulse to the grid of a triode which is not conducting current, or (3).

to the application of a negative pulse to the common anode terminal of a trigger circuit having a resistor common to both its anodes. In all cases, the control pulses are applied to the input terminal of the lowest decade.

The selector for producing a desired control effect in response to different numbers of pulses applied to the input termina1 of the lowest decade may be either in the form of a separate selector switch for each decade or in the form of a single selector switch for all the decades.- In either case, (1) the application of pulses is started by completion of a circuit between the source of pulses and the input of the lowest decade, and (2) this circuit is interrupted and a control pulse is applied to the controlled device when a number of input pulses predetermined by the setting of the selector switch or switches has been applied to the input terminal of the lowest decade.

The principal object of the invention is the provision of an improved control system and method of operation whereby a control pulse is produced in response to any desired number of input pulses. Important objects of the invention are the provision of a control system which is adapted to limit an operation to a selected time interval, and the provision of a control system which is adapted to respond to a selected number of pulses for producing a measuring or counting effect.

The invention will be better understood from the following description considered in connection with the accompanying drawings and its scope is indicated by the appended claims.

Referring to the drawings:

Fig. l is a wiring diagram of the control circuits of one form of the invention, the counters or decades being shown as blocks bearing a switch blade and fixed contacts numbered ii to 9.

Fig. 2 is a wiring diagram of one form of counter or decade.

Fig. 3 illustrated a modified form of control circuit, and

Fig. l is a wiring diagram of a preferred form of the invention which has the advantage that it is simpler and involves fewer parts than the modifications of Figs. 1 to 3.

The computer of Fig. l is shown as including three chains of multi-vibrators or trigger circuits Zil, 2i and 22. These chains are designed in manner well known in the art so that the chain 22 completes its cycle in 0.01 second, the

chain 2! completes its cycle in 0.1 second and the chain 2 3 completes its cycle in 1.0 second. As a result, each rnultivibrator unit of the chain or decade 22 represents 0.901 and those of the decades 2! and 2% represent respectively 0.01 second and 0.1 second. These decades are so interconnected that each time a lower decade completes its cycle, it delivers one pulse to the :inputsterminal of the next higher decade. For example, the three decades of Fig. l are capable of measuring a time interval of 1.000 second or any shorter time interval down to 0.001 second. This time of time computing device is well known and readily understood without detailed explanation.

The present invention relates to theme of such a computer to select or indicate different intervals of time dependent on the setting of the-computer. To this end, a switch 23 is provided for starting and stopping the time measuring operation, the stopping of the operation being effected through a nrultigrid tube 24 having grids '25, 2 6 and 21 a-cathode 2-8, and an anode 29 connected to a positive terminal through a resistor Associated with the decade 22 is a lead 3| which is coupled through a capacitor 32 to the grid 21 and'is connected to a switch blade which is arranged to engage fixed contacts e, i, *2, 3, 4, '5, '6, 'l, 8 and 9 for connecting the lead3l to any one pf themultivibrator units of the chain or decade 22. If the blade is in engagement with the fixed contact i, apositive pulse is applied to the grid 27 each time a count is registered on the corresponding multivibrator of the decade. Similarly the decades 2i and 26 are provided respectively with 'leads 33 and 35 and with fixed switch contacts numbered in the same manner as those of the decade 22, the lead 33 being connected through a resistor 34 to the grid {25 and the Plead 35 being connected through aresistor 36 tothegrid-ZB.

The tube "2d takes-current only when all three of ,its grids are made more positive. This can be made 'to'occur in response to the application of any desired number of pulses to the decades Z-2i--22. i or example, closure of the switch for decade 22, the switch Bof decade 2! and the switch of decade means that all three grids will be positive only at a period of 0.567 second after the time measuring operation is started. At the end of this period, the tube 2Q draws current through a resistor '30 thereby producing a negative pulse at the grid of the switch 23 and operating this switch to interrupt the application of input pulses from a source 38 through a control tube 39 to the input of the decade 22.

The switch 23 "includes a pair of trigger circuits 4t and 1, and a duotriode d2 which (1) is provided with aresistor common to its two anodes and (2) has its anodes-connected through a resistor M to the first control grid c5 of the control tube 39. 'Bias potential is applied from a lead 48 through resistors l"! and d8 respectively to the left hand grids 59 and 5?) of the trigger circuits so and and from the lead 46 through a reset switch 5! and resistors 52 and "53 respectively to the right hand grids 54 and 36 of the trigger circuits Ail and il. Opening and closing the switch 51 puts the trigger circuit units it and $1 in a standby condition with Current conduction in their right hand anodes as indicated by the arrows. Under these conditions, the grid '55 of the duotriode 42 is more positive, the grid 55 of the duotriode 42 is more negative, and sufiicien-t current flows in 4 the resistor 43 to maintain the grid of the control tube 39 at such a potential that no pulses are supplied from the source 33 through the control tube 39 to the decade 22.

The supply of pulses to the decade 22 is started by closing and opening switch 5? which functions .to ,transier current conduction to the left hand anode of the unit :20 thereby making the grid more negative, reducing the current of the resistor 43 and applying to the grid 35 a more positive potential such that oscillations are transmitted through the control tube 39 to the decade 22..

'With the switch blades of the decades 20, 2! and 22 set .as illustrated, the tube 24 is biased off for any number of input pulses less than 567. When the number of input pulses reaches 567, grids 25 and 2B are positive by conduction and a positive pulse is applied to the grid 2? through the capacitor 32. As a result, the tube 243 draws current through the resistor 36, a negative pulse is applied through the lead 3? to the grid 36, current conduction oes to the left hand anode of the unit 4!, the grid 56 is made more positive, more current is drawn through the resistor :33, and the potential of the grid 45 is made sufficiently negative to stop the supply of pulses through the control tube '39 "to the decade 29.

The decades 28, 25 and 22 of Fig. 1 may be i of various types such as (1) that illustrated by Fig. '2 wherein a dillerent trigger circuit is provided for ,each digit of the decade or (2) those illustrated by l wherein a smaller number of trigger circuits are combined with a resistance network to provide the required dig-ital representation.

For convenience in understanding there *is illustrated in Fig. 2 a decade which (1) includes ten trigger circuit units 58 to 67 which are connected through a lead 555 in a closed loop or chain and (2) may be taken as representative of the decades 2?), 2i and22 of Fig. l.

Operating potential is applied from a terminal '59 to the anodes of the units '58 to 6'! through separate resistors cc to '59, bias potential is applied to their grids from leads and 3! through resistors d2 to mi, and a reset switch N32 is provided for putting the decade in a standby condition with current conduction in the anode resistors '50, 513 65, 5?, 59, H, l3, l5, Ti and 19. Input pulses are applied to the left hand grids of the various units through a lead Hi3 and the capacitors to H3. It will be noted that the left hand anodes of the units 58 tol are each coupled to the left hand grid of the next successive unit through a capacitor l M and that the triodes of each unit have their grids and anodes cross-connected as previously explained so that only one triode of the unit conducts current at a time.

The operation of such a decade as this is too well known to require detailed explanation. It is based on the fact that (1) only one of the units 58 to 6'! is conducting current through its left hand anode at any given time, (2) all the other units are insensitive to a negative pulse applied through the terminal [63 and the capacitors I04, ['05, etc., (3) such a negative pulse functions to transfer current conduction from the left anode to the right anode of the one :unit, and (4) there is applied from the left anode of the one unit through a capacitor M4 to the left hand grid of the next successive unit a positive pulse whereby current conduction is transferred from the right to the left anodeo'f this next successive unit which is thus made sensitive to the next negative pulse applied from the terminal I 03 through the corresponding capacitor to the grid of the conducting triode. This process continues throughout the decade, the cycle of operation being repeated over and over again so long as negative pulses are applied to the terminal I03.

With the setting of the selector switch as illustrated in Fig. 2, a positive pulse is applied through the lead 3| and the capacitor 32 to the grid 21 (see Fig. 1) each time current conduction is transferred from the left to the right anode of the unit 64. Each time the decade 22 completes its cycle of ten counts, a positive pulse is applied through a coupling capacitor II to the grid of a triode I I6 and a negative pulse is applied from the terminal III to the pulse input terminal of the decade 2!. The decade M is similarly connected to the decade 20. Thus with the three selector switches set as illustrated in Fig. 1, all three grids of the tube 24 are made positive only when current conduction is transferred from the left to the right anode (1) of unit 64 of decade 22, (2) of unit 63 of decade 2I, and (3) of unit 52 of decade 26. This corresponds to a count of 567 pulses. It is obvious that any other desired number of pulses may be selected to terminate the supply of pulses and to energize a control device connected to the terminals III] and I 26 of Fig. l.

The modification of Fig. 3 is similar to that of Figs. 1 and 2 with the exception that difierent means are provided for applying the stop signal to the switch 23. In this case, the pentode 24 of Fig. 1 is replaced by a triode I2I. Grid bias potential for the triode I2I is derived from a resistor I22 which has its high voltage terminal connected to the anodes of diodes I23, I24 and I25. The cathodes of these diodes are connected to the selector switch blades of the decades 22, 2| and 20 respectively.

With the three selector switches in their illustrated positions, all three diodes draw current only when current conduction is in the right hand anodes of the unit 64 of decade 22, the unit 33 of decade 2! and the unit 52 of decade 23. When all three diodes conduct current, the grid of triode I2I becomes suiiiciently negative to stop current through the anode resistor I 26, and a positive control pulse is delivered to the lead 31 of the stop switch 23 (Fig. l) and to any other controlled device which may be connected to this lead.

The modification of Fig. 4 is preferable to those previously described for the reason that it involves fewer trigger circuits and is controlled by a less complicated selector mechanism, It is distinguished by the fact that (1) the decades consist of only four trigger circuit units so interconnected that they function to deliver one output pulse in response to ten input pulses, (2) a single selector mechanism is provided for all the decades, and (3) the whole control system operates continuously to deliver a positive output pulse in response to input pulses, 12 input pulses, 25 input pulses, as input pulses or 100 input pulses dependent on the setting of this single selector mechanism. The decades of this modification are likethose disclosed in my copending application Serial No. 580,446, in that they include a feedback connection from the left hand anode of the fourth trigger circuit of the decade to the right hand grid of the second trigger circuit and from the left hand anode of the third trigger circuits to the right hand grid of the second trigger circuit so that an output pulse is delivered to the next decade only when ten input pulses have been applied.

The control system of Fig. 4 is illustrated as including two decades I28 and I29. The decade I 28 includes four trigger circuit units I33 to I33 which are of a well known type having operating potential applied to their anodes from a socket power unit I34 through lead I35, a resistor I 36 common to the two anodes or the unit and resistors I31 and I38 which are individual to the separate anodes. Grid bias potential is applied from the socket power unit I34 through leads I35, I48 and MI and resistors I42 and I43. A reset switch I44 connected between the leads I49 and MI is opened and closed to put the decade I28 in a standby condition with current conduction in the resistors I33. Negative input pulses are applied through a coupling capacitor I45 to the common anode terminal of the first or lowest order unit I33 of the decade. Such negative input pulses are derived through a switch I46 and a triode I41 which has its anode I48 coupled through a capacitor I49 to the grid I55 of a triode I 5| so that the current of the triode I5I is increased in response to each input pulse and a negative pulse is produced at the terminal I52 of the resistor I53.

The decade I29 is similar to the decade I28.

In both cases the anode I54 of the lower order' unit is coupled through a capacitor I55 to the common anode terminal of the next higher order unit as is usual in counters of this type. The output terminal of the decade I28 is coupled to the input terminal of the decade I23 through a capacitor I53 so that one pulse is delivered to the decade for every ten pulses applied to the input of the decade I28.

The left hand anode of the unit {33 is com nected through a feed-back connection I6IJ-I5I to the right hand grid of the unit I32 and the lefthand anode of the unit I33 is similarly connected to the right hand grid of the unit I3I through a feedback connection USS-I33. The correspond-- ing units of the decade I 29 are similarly interconnected. With these connections, each decade of four triodes delivers one output pulse in response to ten input pulses.

Positive output pulses are delivered from the common anode terminal I65 of a pair of triodes I66 and I61 which are connected to the high voltage terminal I35 through a resistor I68. So long as the triodes I66 and I61 take current, the output terminal I56 is more negative. When the current drawn through the resistor I68 decreases, the terminal I56 is made more positive. The amount of current drawn through the resistor I 68 is determined by the potential applied to the grids I18 and H! of the triodes I65 and I61. Such potential is controlled by a selector switch I12 which is connected to the decades I28 and I29 so that minimum current is drawn through the resistor I68 only in response to a count of 10, 12, 25, 50 or 100 input pulses.

The selector I12 includes (1) a conductive segment I13 having a contact I14 which is arranged to engage a plurality of .fixed contacts I15 to I18 as segment I13 is rotated around its axis, 2) a conductive segment I19 having a contact I86 arranged to engage a plurality of fixed contacts I8I to I as segment I19 is rotated together with the segment I13, and (3) a pair of brush contacts I86 and I81 through which the segments I 13 and I19 are connected respectively pulse in .response to any one of a lected groups of input pulses. Such :control assures to the control grid of the triode I61 and to the grid of the triode I66.

With the selector I12 in its illustrated posi tion, the grids I and I'll are both connected to the right hand anode of unit IzB-I of the decade I129. .Since current conduction is transferred to the right hand anode of the unit I9I only in :response to each 100 input pulses, it is apparent that a positive pulse be delivered through the capacitor I92 tothe output terminal I56 for each 10.0 input pulses.

With the selector in a position such that the contact 114 engages the contact I and the contact I 8l] engages the contact I82, (1) a negative potential is applied from the right anode of the unit I33 through contacts I14, I15 and I86 to the grid I10 and (2) a negative potential is applied from the left anode of the unit I00 and the left hand anode of the unit I88 through contacts m2, I80 and I81 to the grid I'll. Since this condition of the decades represents a-count of 50 input pulses, it follows that a ositive pulseis delivered at the terminal I56 for each 50 input pulses.

When the selector I12 is in a position such that the contact flie'ngages the contact I16 and the contact I20 engages the contact I83, (1) the grid I10 is connected through contacts 186, I'I l and I16 to the left hand anode of the unit I32 and the left hand anode of the unit I30 and is made negative in response to a count of input pulses and ('2) the grid IEI is connected through contacts I81, I80 and I83 to the left hand anode of the triode tube unit I89 which is pulses may provide a measure of time, a uneasure of numbers of articles or the like depending on the use made of the invention.

I claim as my invention:

1. The combination of firstand second counters each having an input lead and an output lead and each including four trigger circuits so interconnected that its cycle .of operati n is completed inresponse to the application of ten pulses to its input lead, means coupling the output lead of said first counter to the input lead of said second counter, unitary switching means connected to said first and second counters to select from said counters pairs of potentials each pair of which is more negative only in response "to the application or "a different predetermined number or pulses to the input lead of said firstcounter, and means responsive to each of said pairs 101E more negative potentials for producing a single output pulse.

- 2. The combination of first and second counters each having an input lead and an output lead and each includingfour trigger circuits so interconnected that its cycle of operation is completed in response to the application of ten pulses to its input lead, means coupling the output lead of said first counter to the input lead of said secand counter, unitary switching means connected also negative at the count of 25 input pulses. A

positive output pulse is therefore delivered at the terminal B in responseto 25input pulses.

When the selector 'IIZ is in a position such that the contact I" engages the contact I" and the contact I engages the contact I84, the grid I10 is connected through contacts I86,- I'M and IT! to the left hand anode of the unit I3I and the grid I'll is connected through contacts I81, I80 and I84 to the left hand anode of the unit I88 so that both grids are made negative in response to a count of 12 input pulses and a positive pulse is delivered at the output terminal I55. When the selector I12 is in a position such that the contact I14 engages the contact I18 and the contact I80 engages the contact I85,

the grid I153 is connected-through the contacts I86, 114 and M8 to the right hand anode of the unit I33 and the grid I'II is connected through the contacts I 31, I80 and I85 to the left anode of the unit I88 so that both grids are made negative in response to ten input pulses and a positive output pulse is delivered at the output terminal .I 56.

The output pulse delivered at the terminal 456 obviously may be utilized for a variety of purposes such as moving an empty container into a position to receive a counted number of articles or the like. The input pulses applied through the capacitor I45 may be produced by such articles obstructing the light applied to a photoelectric cell as they drop into the conr tai-ner. Other uses vfor the control system e111 be apparent to those skilled in the art.

What the invention provides is a control system which maybe adjusted to produce a control number of seto said first and second counters to select from said counters pairs of potentials each pair of which is more negative only in response to the application of a difierent predetermined number of pulses to the input leadof said first counter, and a pair of triodes having a common anode resistor and having their grids connected -to respond to said pairs of potentials efer-producing a positive output pulse at their common anode terminal. Y

IGOR E. GROSDOFF.

asrsusncns CITED The following references are of record in the file of this patent.

UNITED STATES Pi'iTENTS Nature: vol. 125, No. 3156, April 26,1930, Method of Registering Multiple Simultaneous impulses of Several Geigers Counters by Rossi.

Review of Scientific Instruments: vol. 12, February 1941, The Interval Selector. by Roberts.

Electronics: October 1942, Radiation Instru ments Using Geiger Muller Tubes by Weisz.

Electronics: June 1944, ,A Four-Tube Counter Decade by John T. Potter.

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