US3175090A - Counter network including photoresponsive elements - Google Patents

Description

March 23, 1965 c. s. REIS ETAL COUNTER NETWORK INCLUDING PHOTORESPONSIVE ELEMENTS 2 Sheets-Sheet 1 Original Filed Feb. 27, 1958 m oI mm mm CHARLES S. REIS AND IRWIN WUNDERMAN INVENTORS BY Q4 ATTORNEY March 23, 1965 c. s. REIS ETAL COUNTER NETWORK INCLUDING FHOTORESPONSIVE ELEMENTS Original Filed Feb. 27, 1958 2 Sheets-Sheet 2 w v m w s mm R E M m R R T E A SD W SN U A E w of m N Y w M B R mv WT? a w 5 g m United States Patent ()fiice r nses Patented Mar. 23, 1965 4 Claims. ((31.250-269) This is a divisional application of our application Serial No. 717,965, filed on February 27, 1958, now abandoned, and entitled Network Including Photoresponsive Elements.

This invention relates generally to a network including photoresponsive elements, and more particularly to a network of the above character which is responsive to electrical input pulses.

It is a general object of the present invention to provide a multi-stage network including photoresponsive resistance elements which is responsive to electrical input pulses.

It is another object of the present invention to provide a multistage network including photoresponsive resistance elements in which the energization of stages is transferred to successive stages in response to electrical pulses.

It is another object of the present invention to provide a multi-stage network including photoresponsive resistance elements in which the energization of stages may be transferred in either direction to adjacent stages in response to electrical pulses.

It is another object of the present invention to provide a multi-stage network which is response to electrical pulses in which each of the stages includes a light source and at least one photoresponsive resistance element.

It is another object of the present invention to provide a decade counter employing light sources and photoresponsive resistance elements.

It is another object of the present invention to provide a counter which employ-s light sources and photoresponsive resistance elements arranged in a plurality of stages.

It is another object of the present invention to provide a counter which employs light sources and photoresponsive resistance elements capable of counting forward or backward.

These and other objects of the invention will become more clearly apparent from the following description when taken in conjunction with the accompanying drawings.

Referring to the drawings:

FIGURE 1 is a schematic diagram of a network including photoresponsive elements in accordance with the invention;

FIGURE 2 is a schematic diagram of a network including a pair of decade counters connected in cascade;

FIGURE 3 is a schematic diagram of still another network which includes photoresponsive elements;

FIGURE 4 is a network similar to that of FIGURE 1, providing means for transferring the information in either irection;

FIGURE 5 is a network in accordance with the invention including incandescent light sources;

FIGURE 6 shows a voltage-current characteristic for a light source suitable for use in one embodiment of the invention; and

FIGURE 7 shows a voltage-current characteristic for a light source suitable for use in another embodiment of the invention.

The network is generally in the form of a ring with the energization of the various stages being transferred successively around the ring in response to electrical input pulses.

The network illustrated in FIGURE 1 includes a plurality of stages 11-20. Each of the stages includes a light source 22, a resistive element 23 serially connected with the light source, and a photoresponsive resistance element 24 having one terminal connected to the common junction of the light source 22 and resistive element 23, and its other terminal connected to an input line 26. A voltage source is applied across the serially connected light source 22 and resistor 23 of each stage. As indicated, the voltage source is a negative source V and is connected to one terminal of each of the light sources through a current limiting resistor 27. As will presently become apparent, the voltage source may be a positive source.

The light sources 22 may be of the type which become luminant upon application of a predetermined threshhold voltage, and once a source becomes luminant, the voltage required to maintain the source in a luminant state drops to a value considerably less than the threshhold or breakdown voltage required to transfer the same from a dark to a luminant condition. For example, each of the sources 22 may be a neon bulb which has a voltage current characteristic of the type indicated generally in FIGURE 6. However, as will become presently apparent, the light sources may be incandescent lamps connected in circuit with a photoresponsive element.

Operation of the circuit of FIGURE 1 is as follows: Assume for purposes of illustration that the light source 20-22 is luminant, that is, that the count on the ring counter is zero. The light from the light source 20-22 impinges upon the photoresponsive element 11-24 thereby reducing its resistance. Application of a positive electrical pulse 28 to the line 26 will be transmitted through the photoresponsive element 11-2 to the common terminal of the light source 11-22 and resistive element 11-23. This pulse will increase the voltage across the light source 11-22 above the break-down voltage and the source be comes luminant. The current which flows through the light source 11-22 during the pulse interval is considerable since the resistance through the element 11-22 and 11-24 is very low. The current limiting resistor 27 limits the amount of current which may flow from the voltage source -V. As a result, a large percentage of the limited current will fiow through the light source 11-22. The current through the light source 20-22 will. be relatively low and the same source 20-22 reverts to its non-conducting dark state. Upon termination of the pulse 28, the light source 20-22 is dark and the source 11-22 is energized or illuminated. Thus upon application of one pulse, the energization has been transferred from the light source 20-22 to the light source 11-22. Application of subsequent pulses 28 will serve to transfer the energization of the light source 22 down the chain to the right in the illustration. The apparatus is connected in the form of a ring whereby the tenth pulse is applied through the photoconductive element 23-24 to the light source 20-22 to return the same to a zero count. It is of course to be understood that reference to a decade counter is merely for illustration since the circuit may be employed to divide by any desired number.

In applications, such as in a decade counter, the count may be on any one of the stages upon completion of a particular count. Thus, it is desirable to be able to reset the counter to zero prior to beginning a new count. Referring to the figure, an input reset line 29 is connected through a resistor 30 to the common terminal of the light source 20-22 and the resistor 20-23. Upon application of a positive pulse 31 having sufficient amplitude to make the stage 2% conducting the conducting state will be automatically transferred to the stage 20 and whatever stage 7 going operated at rates up to 30 cycles.

is energized will become de-energized in the manner previously described.

For counting larger counts one may employ more stages. However, in decimal systems, it is preferable to cascade a plurality of decade counters thereby reducing the number of stages required for high counts. Referring to FIGURE 2 a suitable means for forming a pulse every tenth input electrical pulse 28 to the counter is shown. In FIGURE 2 a pair of decade counters 32 and 33 are illustrated with only the first and last stage of the decade counter 32 shown and the first two and last stage of the counter 33 shown. Since these counters are identical to the ring counters shown in FIGURE 1, they carry like reference numerals to indicate like parts. The circuit which serves to form an additional pulse 3 5 for application to the second decade 33 comprises a pair of photoresponsive elements 36 and 37, and a capacitor 33. The photoresponsive element 36 is arranged to be illuminated by the light source 1922. The photoresponsive element 36' has one terminal connected to a voltage supply +V and its other terminal connected to one terminal of the capacitor 38 whose other terminal is grounded. Thus, when the light source 19-22 is luminant, it serves to reduce the resistance of the photoresponsive element 36 whereby substantially full voltage +V is applied to the capacitor 33 to charge the same. The photoresponsive element 37 'is arranged adjacent to the light source 29-22. Thus, when the count is transferred from 9 to 0 that is, the tenth input pulse the photoresponsive element 37 is illuminated thereby reducing its resistance. The voltage on the capacitor is applied to the photoresponsive el ments 24 of the counter 33 and serves to energize the next succeeding stage in the counter, as previously de scribed. Subsequent cascaded decades may be supplied and connected in a similar fashion whereby an output pulse is formed every tenth, hundredth, thousandth, etc., to provide means for counting any desired numbers.

'Apparatus was constructed in accordance with the disclosure of FIGURES 1 and 2 and the elements had the following values:

Light sources 22NE2 Resistors 2347K ohms Photoresponsive devices 24:

megohoms dark 15K ohms light Photoresistive elements 36 and 37:

' 15 megohms dark 15K ohms light Capacitor 38.1 microfarad Voltages:

V-200 volts V 200 volts |V--5 0-200 volts R27-39OK Pulses 2840100 volts Reset pulses 3110O volts Apparatus constructed in accordance with the fore- The rate of operation being dependent only upon the response time of the photoresponsive elements.

The embodiment of FIGURE 3 shows a ring counter in which only the three left-hand stages 2 11 and 12, and two of the right- hand stages 18 and 19 are shown since all of the other stages are identical. A plurality of light sources 42 which may be of the type previously described are serially connected with photoresponsive elements 43 across a bias source +V. A current limiting resistor45 is serially connected with the voltage source +V to limit the current drawn by the energized stage. A photoresponsive element 44 has one terminal connected to the common junction of the light source 42 and photoresponsive element 43 and its other terminal connected to the line 46. Photoresponsive elements s7 are connected in shunt with their respective light source 42.

Operation of the circuit is as follows: When a negative pulse 49 is applied to the line 46, it serves to increase the voltage across the element 42 thereby energizing the same. The photoresponsive element 43 is arranged to receive light from the light source 42 and thereby has its resistance decreased. When the pulse 49 terminates, the associated light source 42 remains illuminated since the resistance of the path is considerably reduced. The photoresponsive element 47 associated with a preceding light source is connected to receive light from the succeeding light source 42. The element 47 is connected in shunt with the preceding light source. When it is illuminated, it provides a low resistance path in shunt with the light source thereby extinguishing the same. Light from the source 42 also impinges on the photoresponsive element :4 of the next adjacent stage thereby conditioning the same to transmit the next input pulse to its associated .light source to thereby ignite or energize the next succeeding stage. Operation of the circuit in response to pulses is to propagate the energized or lit stage down the counter from one stage to the next successive stage.

It is noted with respect to the circuit of FIGURE 3 that the voltage-current characteristics of the lightsources 22 are not important. The photoresponsive element 43 in series with the associated lamp gives the required voltage current characteristics. That is, the voltage required to sustain the stage drops as the resistance 43 is reduced. Further, the stages extinguish since the photo responsive elements 47 provide the extinguishing.

To reset the counter to zero, a pulse 51 is applied to the line 52 which pulse serves to ignite the associated light source 2tl-42. The pulse 51 is also applied to an electronic or other suitable switch 53 and serves to open the circuit thereby removing the biasing voltage +V for an instant whereby any energizing stage becomes de-energized. The switch is then closed prior to termination of the pulse 51 whereby the stage 20 is ignited or energized.

Referring to FIGURE 4, a circuit similar to'that of FIGURE 1 is shown. The various polarities have been reversed to show that a circuit may be constructed to operate with either polarity. The circuit of FIGURE 4 is arranged whereby the ignited or energized stage may be transferred to the right or left by applying pulses 61 and 62 to the lines 63 and 64 respectively. The circuit includes a plurality of stages indicated as 20, 11, 12, 13, etc. Each of said stages includes a light source 22, a resistor 23 connected in series with the light source to receive the bias potential -|-V through a current limiting resistor 27, and photoresponsive elements 24a and 24b. The elements 24 each have one terminal connected to the line 63 While the elements 24b have one terminal connected to the line 64. The elements 24a are associated with succeeding stages while the elements 24b are associated with preceding stages. The elements 24a are disposed to be illuminated by the preceding light source, while the elements 24b by the succeeding light source.

Operation of the circuit is apparent from the description of the operation of the circuit of FIGURE 1. It is apparent that application of pulses 61 to the line 63 will serve to transmit the energized stage down the series of stages in response to the pulses 61. Pulses 62 on the line 64 will serve to transmit pulses in an opposite dir ti The interstage network described with reference to FIG- URE 2 formed pulses when counting in one direction. A similar network may be employed for forming pulses when counting in an opposite direction. Circuits of the type shown in FIGURE 4 can then be cascaded.

As previously described, other types of light sources may be employed in the multi-stage network of the invention. Thus, incandescent light sources having voltage-current characteristics of the type shown in FIGURE 7 are suitable. A multi-stage network employing incandescent lamps is illustrated in FIGURE 5. The network shown is a decade counter. Only the first four and last two Stages a e illustrated in the drawing. Each stage 1ncludes an incandescent source 71 connected in series With a photoresponsive element 72 and a photoresponsive element 73 having one terminal connected to the junction of the source 71 and element 72, and its other terminal to the input line 26. Resistor 27 is conected in series with the voltage supply V and provides a substantially constant current to the network.

Assuming that regeneration in each stage, that is, a drop in voltage required to maintain the stage energized occurs at one-half rated current, operation of the circuit to transfer the energization from one stage to the next in response to input pulses 28 is as follows: When the lamp current in a state exceeds the regenerative value, the lamp goes on and nearly all the current flows in this stage. The succeeding stage is conditioned since its element 73 is illuminated. Application of a pulse 28 will cause the next lamp to light. If the pulse is of sutlicient amplitude, the current through the lamp will be such that the remaining current is insufficient to maintain the preceding lamp. The lit stage is transferred. By employing extinguishing photoresponsive elements as shown in FIGURE 3, the circuit may be made to operate in a more positive manner.

Thus, it is seen that a novel network including photoresistive elements has been supplied. The network is useful for counting input pulses or for registering or transferring information. The network may employ any type of light source in conjunction with the photoresponsive elements.

We claim:

1. A counter comprising input means, first and second networks each including a plurality of stages, and for each of the stages at least one light source and a resistive means connected in series with said light source, said light source and resistive means having a voltage above which the lig t source becomes luminant and a lower voltage serving to sustain the same, means for applying a bias voltage across said light source and resistive means, said bias voltage being of such value that it serves to maintain the source luminant once it is triggered, at least one photoresponsive resistance element having a pair of terminals, one terminal being connected between said light source and resistive means and the other terminal being connected to receive electrical input pulses appearing at said input means, said photoresponsive element being disposed to re ceive illumination from the light source of the next preceding stage, the counter further comprising a pair of photoresponsive elements serially connected, one of said pair of photoresponsive elements having its free terminal connected to apply input pulses to the second network, the other of said pair of photoresponsive elements being connected to a voltage supply, said one of said pair of photoresponsive elements being arranged to be illuminated by the light source associated with the first stage of the first network, said other of said pair of photoresponsive elements being arranged to be illuminated by the light source associated with the last stage of said first network, and a capacitor connected to the common terminal of said pair of photoresponsive elements and adapted to be charged to the applied voltage when said other of said pair of photoresponsive elements is illuminated and serving to discharge through said one of said pair of photoresponsive elements when the light source of the first stage is illuminated to thereby provide an input pulse to the second network.

2. A counter as in claim 1 wherein each stage of one of the first and second networks includes at least one additional photoresponsive resistance element having a pair of terminals, one terminal being connected between said light source and resistive element and the other terminal connected to receive electrical input pulses appearing at said input means, said one additional photoresponsive resistance element being disposed to receive illumination from the light source of the next succeeding stage.

3. A counter as in claim 1 wherein one of the first and second networks includes ten stages to form a decade counter.

4. A counter as in claim 1 wherein for each stage said resistive means connected in series with the light source is a photoresponsive resistive element and wherein for each stage an additional photoresponsive element is connected in shunt with said light source and adapted to be illuminated by the light source of the next succeeding stage.

References Cited by the Examiner UNITED STATES PATENTS 2,895,054 7/59 Loebner 2502l3 2,900,522 8/59 Reis 250-213 2,907,001 9/59 Loebner 250213 2,949,538 8/60 Tomlinson 2502l3 2,984,749 5/61 Ross 250209 2,985,763 5/61 Ross 250-213 2,988,645 6/61 Wilmotte 250209 2,996,622 8/61 Acton 250-208 2,997,596 8/61 Vize 250213 2,999,165 9/61 Lieb 250208 OTHER REFERENCES Standeven, J. D., Opto-Electronic Ring Counter, IBM Technical Disclosure Bulletin, volume 2, No. 2, 8/ 59.

RALPH G. NELSON, Primary Examiner. DARYL W. COOK, WALTER W. BURNS, Examiners.

Claims (1)

1. A COUNTER COMPRISING INPUT MEANS, FIRST AND SECOND NETWORKS EACH INCLUDING A PLURALITY OF STAGES, AND FOR EACH OF THE STAGES AT LEAST ONE LIGHT SOURCE AND A RESISTIVE MEANS CONNECTED IN SERIES WITH SAID LIGHT SOURCE, SAID LIGHT SOURCE AND RESISTIVE MEANS HAVING A VOLTAGE ABOVE WHICH THE LIGHT SOURCE BECOMES LUMINANT AND A LOWER VOLTAGE SERVING TO SUSTAIN THE SAME, MEANS FOR APPLYING A BIAS VOLTAGE ACROSS SAID LIGHT SOURCE AND RESISTIVE MEANS, SAID BIAS VOLTAGE BEING OF SUCH VALUE THAT IT SERVES TO MAINTAIN THE SOURCE LUMINANT ONCE IT IS TRIGGERED, AT LEAST ONE PHOTORESPONSIVE RESISTANCE ELEMENT HAVING A PAIR OF TERMINALS, ONE TERMINAL BEING CONNECTED BETWEEN SAID LIGHT SOURCE AND RESISTIVE MEANS AND THE OTHER TERMINAL BEING CONNECTED TO RECEIVE ELECTRICAL INPUT PULSES APPEARING AT SAID INPUT MEANS, SAID PHOTORESPONSIVE ELEMENT BEING DISPOSED TO RECEIVE ILLUMINATION FROM THE LIGHT SOURCE OF THE NEXT PRECEDING STAGE, THE COUNTER FURTHER COMPRISING A PAIR OF PHOTORESPONSIVE ELEMENTS SERIALLY CONNECTED, ONE OF SAID PAIR OF PHOTORESPONSIVE ELEMENTS HAVING ITS FREE TERMINAL CONNECTED TO APPLY IMPUT PULSES TO THE SECOND NETWORK THE OTHER OF SAID PAIR OF PHOTORESPONSIVE ELEMENTS BEING CONNECTED TO A VOLTAGE SUPPLY, SAID ONE OF SAID PAIR OF PHOTORESPONSIVE ELEMENTS BEING ARRANGED TO BE ILLUMINATED BY THE LIGHT SOURCE ASSOCIATED WITH THE FIRST STAGE OF THE FIRST NETWORK, SAID OTHER OF SAID PAIR OF PHOTORESPONSIVE ELEMENTS BEING ARRANGED TO BE ILLUMINATED BY THE LIGHT SOURCE ASSOCIATLED WITH THE LAST STAGE OF SAID FIRST NETWORK, AND A CAPACITOR CONNECTED TO THE COMMON TERMINAL OF SAID PAIR OF PHOTORESPONISVE ELEMENTS AND ADAPTED TO BE CHARGED TO BE APPLIED VOLTAGE WHEN SAID OTHER OF SAID PAIR OF PHOTORESPONSIVE ELEMENTS IS ILLUMINATED AND SERVING TO DISCHARGE THROUGH SAID ONE OF SAID PAIR OF PHOTORESPONSIVE ELEMENTS WHEN THE LIGHT SOURCE OF THE FIRST STAGE IS ILLUMINATED TO THEREBY PROVIDE AN INPUT PULSE TO THE SECOND NETWORK.

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