US2470926A - Electronic counter - Google Patents

Description

y 1949- w. A. GIESEKE 2,470,926

ELECTRONIC COUNTER Filed Feb. 27, 1946 2 Sheets-Sheet l May 24, 1949. w. A. GIESEKE ELECTRONIC COUNTER 2 Sheets-Sheet 2 Filed Feb. 27, 1946 AMA, Ali'- ernaf Z dz'aseke Patented May 24, 1949 UNITED STATES PATENT OFFICE ELECTRONIC COUNTER Werner A. Gieseke, Danville, Ill.

Application February 27, 1946, Serial No. 650,663

Claims. 1

My invention relates to electronic counters and more particularly to a high speed device employing light interruptions on a phototube as a means of setting up impulses in an electronic circuit which are effective to cause the operation of a counting mechanism of any character.

One object of the invention is to provide a counter of the character indicated in which the electronic means are operated by direct current, thus enabling a connected, mechanical register ing device to be operated at high speed.

A further object is to provide an electronic counter arranged to convert short electrical impulse set up objects moving at high speed into impulses of longer duration that allow for the inertia of and are capable of operating the mechanical parts of the counter.

A further object is to devise a counter characterized by the above features in which the impulse broadening stage acts as a trigger for the power stage of the circuit which is coupled to electrical means for operating the registering mechanism of the counter.

These and further objects of the invention will be set forth in the following specification, reference being had to the accompanying drawings, and the novel means by which said objects are efiectuated will be definitely pointed out in the claims.

In the drawings:

Fig. l is a schematic arrangement showing one method of passing the objects to be counted through the focal point of light rays incident upon a phototube which forms part of an electronic circuit.

Fig. 2 shows a variant method of presenting the objects to be counted to the optical system of the counter.

Fig. 3 illustrates a circuit layout which may be used with either of the arrangements shown in Figs. 1 and 2.

Referring to Fig. 1, the numeral I0 designates a hopper into which the articles to be counted may be deposited manually or mechanically. The hopper includes a delivery passage H arranged for gravity feed of the articles and sized to permit only the flow of single articles one behind the other. Each article is dropped through the focal point 12 of an optical system comprising a light source !3 Whose rays are focused by a lens I4 for incidence on a phototube I5. Each interruption of the rays on the phototube generates an electrical impulse that is transmitted to an amplifying circuit, generally indicated by the numoral it, which in turn conditions the impulse so that it may be employed to set in operation a counting mechanism ll, all as specifically explained hereinafter in connection with the circuit arrangement shown in Fig. 3.

In 2, the articles l8 to be counted are deposited in any desired manner on a conveyor 59 which carries the articles successively through the focal point of an optical system comprising a ight source and a lens 2!. The conveyor belt characterized by sufficient transparency to enable the light rays to become incident on a photo tube 22 which is related to an amplifying circuit 2.3 and a counting mechanism 2d to accomplish general operation noted above and as presently described in detail.

The circuit arrangement for effecting the counting action is illustrated in Fig. 3. Generally speaking, the capacity to count at high speed, i. e., as many as one thousand pieces per minute, is due to direct current operation of the circuit stages including the phototube which sends negative impulses to an amplifier that is coupled to a trigger circuit which in turn is connected to a power stage, the latter controlling operation of a mechanical counter through a solenoid, for example, or any type of control mechanism and is particularly suitable for controlling those devices which are characterized by rapid, cycling motions.

Specifically, a power source for the phototube and amplifying phases of the circuit is provided by a transformer 25 having a primary Winding 26 and secondary windings 27, 28 and 29. The winding 27 is connected to the directly heated cathode of a duo-diode tube 30 while the plates of this tube are respectively connected to the terminals of the winding 28. Also connected to one terminal of the winding 21 is a wire 3i including in series relation a fuse 32 and a choke coil 33 whose end is connected to ground by a wire 34 which includes a capacitor 35. The winding 28 is center tapped by a wire 3E which connects with the wire 34. This arrangement provides a full wave rectifier employing an L-type filter constituted by the coil 33 and capacitor 35 which supplies direct current voltage for the operation of the stages involving a phototube 36, a pentode amplifier 3'! which in conjunction with the associated circuit acts to invert impulses generated by the phototube 36, and a thyratron tube 38 which in conjunction with the associated circuit broadens the impulses received from the amplifier and acts as a trigger for the power stage of the circuit which is separately supplied by direct current as hereinafter described.

Leading from the junction of the wires 3| and 34 is a wire 39 and connecting the latter to ground is a voltage divider 49 comprising fixed resistors 43, 4 2 and 43, and a potentiometer 44. A wire 45 connects the potentiometer 44 with the oathode of the amplifier 31 while the plate of the latter is connected by a wire 45 having a fixed resistor 4'! with the wire 39. The cathode of the phototube 36 is connected to ground by a wire 48 having a fixed resistor 49 while the anode of the phototube is connected to the voltage divider 49 between the resistors 42 and 43. The control grid of the amplifier 3'! is connected to ground by a wire i through a resistor 52 and a capacitor 53 is bridged between the wires 48 and 5i on the output ends of the resistors 49 and 52. The resistor 52 and capacitor 53 function as a grid leak bias for the control grid of the amplifier 31.

A wire 54 having a resistor 55 provides connection between the control grid of the trigger tube 38 and the wire 46 at a point between the plate of the amplifier 31 and the resistor 41. The cathode of the trigger tube 38 is connected to a filter comprising a resistor 56 and a capacitor 51 and the plate of the trigger tube is connected by a wire 59 to the wire 39. Also connected to the wire 39 and in parallel with the trigger tube 38 is a wire 6| which includes a resistor 62. The lower end of the wire 6! is connected to a wire 63 which at one end connects with the filter 56-51 and at the opposite end with the power driving stage presently described, and also with a wire 64 including a resistor 65 which leads to ground.

It will be understood that the terminals of the secondary winding 29 are connected to the filament of the amplifier 3'! and that this winding is center tapped at 66 for connection to the amplifier cathode. For the filament of the trigger tube 38, a separate transformer 61 is used having primary and secondary windings 68 and 69, respectively. The terminals of the secondary winding 69 are connected to the filament of the trigger tube 38 while a center tapping of this winding connects with the cathode of the trigger tube. For the sake of clearness, the connections referred to in this paragraph have not been illustrated in the drawing.

A separate transformer H is employed for the power driving stage of the circuit and it comprises a primary winding 12 and secondary windings i3, i4 and 15. The terminals of the winding 13 are connected to the plates of a duo-diode tube 16 whose cathode is connected to the upper end of a voltage divider 11 comprising the fixed resistors 18 and 19 and potentiometer 80. A wire 8! connects the potentiometer 80 with the cathode of a Vacuum type power tube 82 which constitutes the power driving stage of the circuit and whose plate is connected to one end of the coil of a solenoid 83, the opposite end of the coil being joined to a wire 84 that connects with the upper end of the voltage divider I1 and with the cathode of the tube 16. It will be understood that the core of the solenoid is suitably related to the counting mechanism I! or 24 so that the latter will be actuated when the core is shifted in the manner hereinafter described.

The secondary winding 73 is center tapped by a wire 85 which connects with the input end of the potentiometer 80. Capacitors 86 and 81 are res'pectively interposed between the wire 85 and the upper end of the solenoid coil, and between the wires 85 and 8|. The potentiometer and capacitor B! constitute a variable cathode, resistorcapacitor filter for providing a variable cathode biasing of the power tube 82 to establish the correct operating point for the solenoid 83. From the foregoing, it will be obvious that the tube 16 and associated circuit provides a full wave rectifier employing a resistor-capacitor filter for supplying direct current voltage for the operation of the power tube 82 and the solenoid 83.

The power and amplifying stages of the circuit are linked by a resistor 88 which connects the output end of the resistor 56 with the control grid of the power tube 82 and by the wire 63 which connects with the wire 85.

The terminals of the secondary winding 14 are connected to the filament of the power tube 82 and the same winding is center tapped by a wire 89 which connects with the power tube cathode. Power for the light source !3 or 20 may be supplied by the secondary winding I5. The connec tions referred to in this paragraph, including the light source, are not shown in the drawing for the sake of clearness.

The operation of the circuit shown in Fig. 3 will now be described in connection with the article feeding and optical system shown in Fig. 1, it being understood that the circuit functions in an identical manner for the arrangement illustrated in Fig. 2.

So long as light rays from the source [3 are incident on the phototube 36, the amplifier 31 conducts normally by reason of the variable cathode bias provided by the potentiometer 4i and the grid leak bias constituted by the resistor 52 and capacitor 53. However, when an article to be counted passes through the focal point of the optical system shown in Fig. 1, the shadow cast on the phototube 36 interrupts the conduction of electrons therethrough and the potential at the top of resistor 49, normally positive, drops to that of ground. Then through the action of the capacitor 53 and resistor 52, an impulse of negative polarity is sent to the control grid of amplifier 3! so that the conductance of the latter dcreases and its plate voltage increases for the duration of the incoming impulse from the phototube.

It will be noted that regardless of the size or shape of the object to be counted, the negative impulse fed, to the control grid of the amplifier 31 retains its standard size because of the time constant characteristics of the resistor-capacitor combination 52-53, or, in other words, the phototube always sends the same impulse regardless of the time interruption of the light rays with respect to any given values of the resistor 52 and capacitor 53.

The trigger tube 38 is normally not ionized due to the grid bias developed across the resistors 41 and 55 and by the cathode bias developed across the resistors 59 and 62, i. e., during periods of light incidence on the phototube. However, when conductance through the amplifier 3'; decreases as above described, the voltage drop across the resistor 4? also reduces and the grid bias of the trigger tube 38 is driven towards zero and slightly in a positive direction. Hence, during periods of light interruption, the amplifier 3'! and the associated circuit acts as an impulse inverter, changing the negative going, input impulse to a positive going, output impulse which triggers the tube 38 as will be presently described. The amplifier also has impedance matching characteristics which match the output of the phototube to the input of the trigger tube.

The positive impulse from the plate of the amplifier 31 causes the trigger tube 38 to ionize and the current flow through the cathode resistors 56 and 65 causes the cathode of the tube 38 to go more positive for the duration of the incoming impulse and this positive going, cathode voltage is fed to the control grid of the power tube 82 which thereby becomes ionized. When the power tube 82 fires, current flow through its plate circuit is increased sufiiciently to energize the solenoid 83 which may be hooked with a suitable counting or control mechanism.

Normally, the power tube 82 is biased by resistors 56 and 88, and by the potentiometer 80, but when the trigger tube 38 ionizes, this bias is driven towards zero. It will be understood that the trigger tube 38 may be or may not conduct when the phototube is illuminated, depending upon the biasing of the tube 38, but, whatever the situation may be in this respect, the latters conductance increases when an impulse is fed to its control grid as above described. The trigger tube 38 and the associated circuit function as the impulse broadening stage and is responsible for lengthening the time duration of the impulse fed to the power tube 82 sufiiciently to effect the operation of the counting or registering device.

The general object of the entire circuit is to supply a constant impulse to the tube 82 representing the power stage and, to this end, the amplifier 3'! feeds a short impulse to the trigger tube 38 which in turn supplies an impulse of longer duration to the power tube.

The specific advantage of that portion of the circuitwhich includes the trigger tube 38 centers in the cathode filter constituted by the resistor 58 and capacitor 51. Although the impulse fed to the trigger tube 38v may be of short duration, after which this tube may deionize, the time constant of the capacitor-resistor network 51-56 actually controls the width of the impulse fed to the power tube 82. When the tube 33 ionizes, its cathode goes positive and when it deionizes, the capacitor 51, which was charged when this tube ionized, discharges through the resistor 56 to keep the cathode of the tube 38 at that more positive potential for a time controlled by the characteristics of the 51-56 network.

The trigger tube 38 is deionized by lowering its plate-to-cathode potential to a value equal to the extinction potential of the tube. When the tube 38 fires, the heavy conducton therethrough increases the resistance drops across the resistors 56 and 65, the latter forming part of a voltage divider including the resistor 62 which is connected to the power supply wire 39 and hence to the plate of the tube 38. Since increased conduction through resistor 56 renders the upper end thereof more positive with respect to the opposite end, which ends are respectively connected to the cathode of the trigger tube and through the voltage divider including the resistor 62 to. the plate of the same tube, the cathode becomes more positive with respect to the plate, thus reducin the plate-to-cathode potential to a value equal to the deionizing potential.

It is thus possible to control the time duration of the impulse firing the power tube 82 as necessitated by the time delay required for the operation of the associated mechanical device before the solenoid 83 is deenergized. In other words, without this time delay or impulse broadening and by reason of the short impulse set up by an article moving through the optical system, there would not be sufficient time for the counter, due to its inertia, to perform its allotted task. My improved arrangement therefore is particularly suitable for high speed counting, including those articles which are too light in weight to actuate a conventional switch or trigger.

It will be understood that the values of the resistors and capacitors will be adjusted and related as the particular operating circumstances require.

I claim:

1. In a device for registering the passage of a succession of articles, the combination of an optical system comprising a light source and a phototube for receiving rays from the source, means arranged to pass the articles through the focal point of the system, direct current operated, electronic means associated with the phototube comprising means for inverting impulses set up by the phototube when the light rays thereon are interrupted by a passing article, a trigger tube for receiving the inverted impulses and a power tube fired by the trigger tube, a resistorc'apacitor filter associated with the cathode of the trigger tube and the control grid of the power tube whereby the time duration of each impulse fed to the power tube is lengthened, and solenoid means connected to the plate of the power tube and energized by the firing of the power tube, and the solenoid means being adapted for connection to a registering device.

2. In a device for registering the passage of a succession of articles, the combination of an optical system comprising a light source and a phototube for receiving rays from the source, means arranged to pass the articles singly through the focal point of the system, direct current operated, electronic means comprising an amplifier, a resistor-capacitor couplin associated with the cathode of the phototube and the control grid of the amplifier whereby an impulse of constant size is fed to and is inverted by the amplifier when the light rays on the phototube are interrupted by a passing article, a trigger tube for receiving the inverted impulse and a power tube fired by the trigger tube, a resistor-- capacitor filter associated with the cathode of the trigger tube and the control grid of the power tube whereby the time duration of each impulse fed to the power tube is lengthened, and solenoid means connected to the plate of and energized by the firing of the power tube, the solenoid means being adapted for connection to a registering device.

3. In a device for registering the passage of a succession of articles, the combination of an optical system comprising a light source and a phototube for receiving rays from the source, means arranged to pass the articles singly through the focal point of the system, a normally deionized, power tube, solenoid means having its coil in series with the plate of the power tube and adapted for connection to a registering device,

means for supplying direct current voltage to the power tube and direct current operated, electronic means responsive to impulses set up by the phototube when the light rays thereon are interrupted by a passing article and associated with the power tube, said electronic means comprising means for inverting the impulses and a trigger tube for receiving the inverted impulses and feeding them to the power tube for firing the same, and a resistor-capacitor filter associated with the cathode of the trigger tube and the control grid of the power tube whereby the time duration of each impulse fed to the power tube is lengthened sufiiciently to enable the solenoid means to actuate the registering device.

4. In a device for registering the passage of a succession of articles, the combination of an optical system comprising a light source and a phototube for receiving rays from the source, means arranged to pass the articles singly through the focal point of the system, a normally deionized, power tube, solenoid means having its coil in series with the plate of the power tube and adapted for connection to a registering device, means for supplying direct current voltage to th power tube, and direct current operated, electronic means responsive to impulses set up by the phototube when the light rays thereon are interrupted by a passing article and associated with the power tube, said electronic means comprising an amplifier, 2, resistor-capacitor coupling associated with the cathode of the phototube and the control grid of the amplifier whereby an impulse of constant size is fed to and is inverted by the amplifier when the rays are interrupted, a trigger tube for receiving the inverted impulses and feeding them to the power tube for firing the same, and a resistor-capacitor filter associated with the cathode of the trigger tube and the control grid of the power tube whereby the time duration of each impulse fed to the power tube is lengthened suificiently to enable the solenoid means to actuate the registering device.

5. A device for counting impulses of short duration comprising a phototube intermittently subjected to light rays, direct current operated, electronic means associated with the phototube comprising means for inverting impulses set up by the phototube when the light rays thereon are interrupted, a trigger tube for receiving the inverted impulses and a power tube fired by the trigger tube, a resistor-capacitor filter associated with the cathode of the trigger tube and the control grid of the power tube whereby the time duration of each impulse fed to the power tube is lengthened, and a counter having an actuating coil with inductive characteristics connected to the plate of and energized by the firing of the power tube.

6. A device for counting impulses of short duration comprising a phototube intermittently subjected to light rays, direct current operated, electronic means associated with the phototube comprising an amplifier, a resistor-capacitor coupling associated with the cathode of the phototube and the control grid of the amplifier whereby an impulse of constant size is fed to and is inverted by the amplifier when the light rays on the phototube are interrupted, a trigger tube for receiving the inverted impulses and a power tube fired by the trigger tube, a resistor-capacitor filter associated with the cathode of the trigger tube and the control grid of the power tube whereby the time duration of each impulse fed to the power tube is lengthened, and a counter having an actuating coil with inductive characteristics connected to the plate of and energized by the firing of the power tube.

7. A device for counting impulses of short duration comprising a phototube intermittently subjected to light rays, a normally deionized, power tube, a counter having an actuating coil with inductive characteristics in series with the plate of the power tube, means for supplying direct current voltage to the power tube and direct current operated, electronic means responsive to impulses set up by the phototube when the light rays thereon are interrupted and associated with the power tube, said electronic means comprising means for inverting the impulses and a trigger tube for receiving the inverted impulses and feeding them to the power tube for firing the same, and a resistor-capacitor filter associated with the cathode of the trigger tube and the control grid of the power tube whereby the time duration of each impulse fed to the power tube is lengthened sufiiciently to effect operation of the counter.

8. A device for counting impulses of short dura tion comprising a phototube intermittently subjected to light rays, a normally deionized, power tube, a counter having an actuating coil with inductive characteristics in series with the plate of the power tube, means for supplying direct current voltage to the power tube and direct current operated, electronic means responsive to impulses set up by the phototube when the light rays thereon are interrupted and associated with the power tube, said electronic means comprising an amplifier, a resistor-capacitor coupling associated with the cathode of the phototube and the control grid of the amplifier whereby an impulse of constant size is fed to and is inverted by the amplifier when the rays are interrupted, a trigger tube for receiving the inverted impulses and feeding them to the power tube for firing the same, and a resistor-capacitor filter associated with the cathode of the trigger tube and the control grid of the power tube whereby the time duration of each impulse fed to the power tube is lengthened sufficiently to efiect operation of the counter.

9. In an apparatus for courting impulses of short duration including a phototube intermittently subjected to light rays, an amplifier, a resistor-capacitor coupling associated with the cathode of the phototube and the control grid of the amplifier whereby an impulse of constant size is fed to and is inverted by the amplifier when the light rays on the phototube are interrupted, a trigger tube responsive to the inverted impulses, a power tube fired by the trigger tube, a resistorcapacitor filter associated with the cathode of the trigger tube and the control grid of the power tube whereby the time duration of each impulse fed to the power tube is lengthened, and a counting device in the output circuit of the power tube.

10. In an apparatus for lengthening impulses of short duration to enable their being counted by a counting device including a phototube inter-. mittently subjected to light rays, an amplifier, a resistor-capacitor coupling associated with the cathode of the phototube and the control grid of the amplifier whereby an impulse of constant size is fed to and is inverted by the amplifier when the light rays on the phototube are interrupted, a trigger tube responsive to the inverted impulses, a power tube fired by the trigger tube and arranged for connection to the counting device, and a resistor-capacitor filter associated with the cathode of the trigger tube and the control grid of the power tube whereby the time duration of each impulse fed to the power tube is lengthened.

WERNER A. GIESEKE.

(References on following page) REFERENCES CITED Number Name Date 2,252,457 Cockrell Aug. 12, 1941 i t; i g gi fs are Of record in the 2,342,753 Pearson et a1 Feb. 29, 1944 p 2,421,991 Carriere June 10, 1947 UNITED STATES PATENTS 5 2,432,084 Blair Dec. 9, 1947 Number Name Date OTHER REFERENCES 1,998,132 Geficken et a1 Apr. 16, 1935 2,049,376 Hertwig et a1 July 28 1936 Electncal Countmg by W. B. Lewls (pages 63- 2,140,350 Dawson 13 1938 64) Published by The Macmillan

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