US3299313A

US3299313A - Pulse generating and counting circuit with disabling means

Info

Publication number: US3299313A
Application number: US394971A
Authority: US
Inventors: Giacchi John
Original assignee: Burroughs Corp
Current assignee: Unisys Corp
Priority date: 1964-09-08
Filing date: 1964-09-08
Publication date: 1967-01-17
Anticipated expiration: 1984-01-17
Also published as: GB1092841A

Description

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Jan.- 17, 1967 J. GIACCHI PULSE GENERATING AND COUNTING CIRCUIT I WITH DISABLING MEANS Filed Sept. 8, 1964 o l :o

INVENTOR. JOHN GIACCHI WW -M COUNTER United States Patent 3,299,313 PULSE GENERATING AND COUNTING CIRCUIT WITH DISABLING MEANS John Giacchi, Somerville, N.J., assignor to Burroughs Corporation, Detroit, Mich., a corporation of Michigan Filed Sept. 8, 1964, Ser. No. 394,971 12 Claims. (Cl. 315-85) This invention relates to pulse-generating circuits and, particularly, to a programmable circuit for automatically generating a series of groups of pulses, with the number of pulses in each group being variable and controllable.

The objects of the present invention concern the provision of an improved automatic and controllably variable pulse-generating circuit which is stable, utilizes its pulsegenerating capabilities to the maximum, and has efiicient, automatic turn-off means.

Briefly, the circuit of the invention includes a multi-position magnetron beam switching tube which is coupled to a multivibrator driver. The beam switching tube and the driver are .coupled together in such a way that, when an electron beam is formed in the tube, it turns on the multivibrator. The multivibrator runs freely and drives the beam switching tube to switch an electron beam from position to position. The multivibrator and the beam switching tube are so related that, when an electron beam reaches a predetermined last position and the last possible pulse has been generated, then the beam switching tube and the multivibrator are automatically turned off. The

circuit of the invention includes an efiicient arrangement for automatically turning off the beam switching tube at the end of a pulse-generating cycle while allowing the tube to generate an output pulse from each of its positions.

The invention is described in greater detail by reference to the single figure of the drawing which is a schematic representation of a circuit embodying the invention.

Referring to the drawing, the circuit of the invention includes a 'multi-position magnetron beam switching tube 16, preferably of the type known as a BeamX switch, which is coupled to a multivibrator driver 18. The device 16 is well known in the art and includes ten positions or groups of electrodes, from each of which an output pulse may be obtained. Each group of electrodes includes a target or output electrode 20, a spade electrode 24 which forms and holds an electron beam on its associated tar-get electrode, a switching electrode 28 which may be used to switch an electron beam from one position to the next, and a shield electrode 32. The spade electrodes 24 may also be employed to perform a beam switching function. A magnetron beam switching tube also includes a cathode 36 and permanent magnet means (not shown) for providing a magnetic field which operates with the electric fields in the tube to control the movement of an electron beam therein. In the drawing, for purposes of simplification, the switching electrodes 28 are shown schematically at one end of the tube envelope, rather than in each group of electrodes.

In the circuit 10 and referring to tube 16, each spade electrode 24 is provided with a signal input terminal 38 and is coupled through a capacitor 40 to ground. Each spade electrode 24 is also coupled through a load resistor 46 to a common spaced bus 48 which is coupled to a positive DC. power supply V1. In addition, according to the invention, the spade electrode at the last position, the 9 position in tube 16, includes in its load circuit a diode 50, oriented as shown, inserted in series with its spade load resistor 46. The cathode of diode 50 is coupled through a bias resistor 52 to spade bus 48. A capacitor 56 is connected between the anode of the diode 50 and a portion of the multivibrator 18, to be described below. Another diode 60, oriented as shown, is connected between the anode of the first diode 50 and the spade bus 48.

. "ice The target or output electrodes 20 of tube 16 are connected in sets, with the tar-gets at the even-numbered positions being connected in one set and to a bus 62, and the targets at the odd-numbered positions being connected in a set and to a bus 66. One end of the bus 62 is coupled through a resistive path both to the switching electrodes 28 at the even-numbered positions and to power source V3, and one end of the bus 66 is connected through a resistive path both to the switching electrodes 28 at the odd-numbered positions and to power source V3. The other end of each

bus

62 and 66 is connected through a separate capacitor 70 to ground.

The cathode 36 of tube 16 is connected through a parallel combination of resistor 74 and capacitor 78 to ground. Cathode 36 is also coupled to multivibrator 1-8 in a manner to be described below. The shield electrodes 32 are connected to a suitable positive DC. power source V2.

The multivibrator 18 may be of generally conventional form and may be made up of two transistors or two tubes,

\ as desired. In the drawing, the multivibrator is shown as comprising two tubes 78 and 80 having

cathodes

82 and 84, control grids 88 and 90, and anodes 94 and 96, respectively. The

cathode electrodes

82 and 84 are connected together and through a resistive path to ground, and the anodes and control grids are capacitively crossconnected. The anode 94 is used to operate a suitable utilization device, for example, a mechanical counter 100, which includes a mechanical relay 102 to which the anode 94 is connected through a resistive path. This resistive path is also coupled to a bus 104 which is coupled to a DC. power source V3. The. anode 94 is also coupled through lead 106 to capacitor 56 and thus to the junction of diodes 50 and 60. The anode 96 is connected through a resistive path to bus 104 and through capacitors 108 to both even-numbered and odd-numbered switching electrodes 28 in tube 16. Each set of switching electrodes 28 is also connected through a resistive path to ground.

The control grid is coupled through separate resistive paths to the bus 104 and to ground. The control grid 88- is connected through resistor 108 and lead 110 to the cathode 36 of tube 16.

The operation of the pulse generator circuit 10 is as follows. The circuit is adjusted so that initially the beam switching tube 16 does not have an electron beam formed therein, and, in the multivibrator, tube 78 is off and tube 80 is on. This condition is maintained by the application of ground potential from the cathode 36 of tube 16 through lead 110 to the grid 88 of tube 78 of the multivibrator. When it is desired to set the circuit in operation and generate a series of pulses, a negative start pulse is applied to one of the spade electrodes 24 in tube 16, say the 0 spade, through its input terminal 38. This pulse applied to the 0 spade causes an electron beam to form and flow from the cathode 36 to the 0 position in tube 16, and the cathode 36 rises in potential to a positive level which is transmitted through lead 110 to the grid 88 of tube 78 of the multivibrator. The multivibrator is now rendered operative and runs freely in known fashion. With each complete cycle of operation of the multivibrator, and, particularly, each time that tube 80 turns on and its anode 96 goes negative in potential, a count is registered in the counter and the beam is moved by one position in the beam switching tube 16.

When finally the electron beam reaches the last position or position 9 in tube 16, the beam is cleared due to the action of the load circuit connected to the 9 spade. When the electron beam is thus cleared, the cathode 36 of tube 16 drops to about ground potential, and this potential transmitted through lead to the grid 88 of tube 78 again disables the multivibrator .18, and the initial conditions are restored in the multivibrator, with tube 80 being on and tube 78 being off. Thus, one cycle of operation is completed.

The aforementioned beam clearing circuit operates as follows. As the multivibrator executes a cycle of operation, anode 94 and its output path are pulsed alternately in positive and negative directions. These positive and negative potential pulses are coupled through the lead 106 to the junction of diodes 50 and 60. At the same time, anode 96 and its output path assume potentials opposite to those of anode 94- and its output path. This mode of operation of a multivibrator is well known. As the multivibrator switches an electron beam from position to position in beam tube 16, but before the beam reaches the 9 position, when a positive pulse appears at anode 94 and on lead 106, this positive pulse passes through diode 60 and out through the low impedance power supply V1 without affecting the potential of the 9 spade. When a negative pulse appears at the junction of the diodes 50 and 60, and whether a beam is present or not in the 9 position, the 9 spade is not affected.

When the beam is in the 8 position, the next negative pulse appearing at anode 96 and on its output lead is coupled to the switching grids 28 and causes the beam to switch to the 9 position. At the same time, the anode 94 and its output lead are pulsed positively. However, this positive pulse, coupled through lead 106 to the load circuit of the 9 spade, is dissipated before the beam forms and locks in the 9 position. Thus, this positive pulse does not affect the switching of an electron beam into the 9 position. The next change in state of the multivibrator applies positive potential to anode 96 and negative potential to anode 94. The change in state of the multivibrator has no effect on the beam or on the load circuit of the 9 spade. However, the next change in state of the multivibrator provides a negative pulse from anode 96 and a positive pulse from anode 94. The latter positive pulse, coupled through lead 106, acts to clear the electron beam from position 9 before it has an opportunity to switch to the next position. The positive pulse produced by anode 94 is applied at the junction of the diodes 50 and 60 and biases diode 50 in the forward direction. This causes the 9 spade to be raised to a positive potential at which it cannot support an electron beam, and the beam is cleared.

In the next and successive cycles of operation, if it is desired to provide a different number of output pulses, then the electron beam is set at some position other than the 0 position in tube 28 by the application of a pulse at the proper terminal 38. After the beam has thus been set at the desired position, the required number of pulses is generated in the manner described above, with each position of the tube 16 being usable in the pulse-generating process.

The circuit of the invention thus provides an improved arrangement for obtaining groups of pulses, with the number of pulses in each group being variable and adjustable. The circuit provides a relatively simple and effic-ient arrangement for, in effect, turning itself on and turning itself otf. The circuit also permits full utilization of each position in the magnetron beam switching tube used as the control means in the circuit.

It is to be understood that various modifications may be made in the circuit shown within the scope of the invention. For example, as mentioned above, the multivibrator might be made up of any known type of semiconductor device. In addition, any utilization device other than a counter might be used to register or display the pulses generated during operation of the circuit.

What is claimed is:

1. A pulse-generating circuit including a multivibrator and a multi-position beam switching tube connected together as a pulse-generating module,

the multivibrator including (1) electrode control means for holding it off or free-running and (2) output means for transmitting output thereby,

the output means of said multivibrator being coupled to utilization means for receiving output pulses and to said beam switching tube whereby each pulse is registered both in said utilization means and in said beam switching tube,

said electrode control means of said multivibrator also being coupled to said beam switching tube whereby the state of operation of said multivibrator, that is whether it is off or free-running, is controlled by the state of said beam switching tube, and

auxiliary circuit means coupled between the output of said multivibrator and one position in said beam switching tube for automatically clearing a beam therein and thus ending a pulse-generating cycle and disabling said multivibrator.

2. The circuit defined in claim 1 wherein said auxiliary circuit means includes a connection from the spade electrode at said one position through a pair of diodes connected anode-to-anode to a power source, the output of said multivibrator being connected through a capacitor to the junction of said pair of diodes, said spade electrode also being coupled through a load resistor to said power supply.

3. The circuit defined in claim 1 wherein said auxiliary circuit means includes a connection from the spade electrode at said one position through a pair of diodes connected anode-to-anode to a power source, the output of said multivibrator being connected through a capacitor to the junction of said pair of diodes, said spade electrode also being coupled through a load resistor to said power pp y.

and an auxiliary resistor connected between the junction of said pair of diodes and said power supply.

4. The circuit defined in claim 1 wherein said beam switching tube includes an electron-emitting cathode and a plurality of groups of electrodes 'in operative relation therewith whereby an electron beam can flow from said cathode to one of said groups of electrodes,

said electrode control means of said multivibrator also being coupled to an electrode in said beam switching tube whereby the state of operation of said multivibrator is controlled by the presence or absence of an electron beam in said beam switching tube.

5. The circuit defined in claim 1 wherein said beam switching tube includes an electron-emitting cathode and a plurality of groups of electrodes in operative relation therewith and adapted to receive an electron beam from said cathode, said electrode control means of said multivibrator being coupled to said cathode so that when an electron beam is formed in said beam switching tube and flows from said cathode to a group of electrode means, the multivibrator changes from the off state to the free-running state and thus generates a group of pulses, said means automatically ending a pulse-generating cycle coupled between the output of said multivibrator and the one position in said beam switching tube for extinguishing an electron beam therein and thus disabling said multivibrator. 6. A pulse generating circuit including a multivibrator and a multi-position beam switching tube connected together as a pulse-operating module,

said multivibrator including two separate discharge devices, each having a control electrode and an output electrode and adapted to be held in two states (1) a free-running state and (2) an off state,

said beam switching tube including an electron-emitting cathode and a plurality of groups of electrodes in operative relation therewith and adapted to receive an electron beam from said cathode, each group of electrodes including a target electrode for receiving pulses generated an electron beam, a spade electrode for forming and holding a beam on its associated target electrode, and a switching electrode for switching an electron beam from one position to another,

one control electrode of said multivibrator being coupled to the cathode of said beam switching tube so that when an electron beam is formed in said beam switching tube and flows from said cathode to one group of electrodes therein, the multivibrator is switched from the off state to the free-running state and thus generates a group of pulses,

one output of said multivibrator being coupled to said switching electrodes of said beam switching tube to cause an electron beam to switch from one position to the next with each cycle of operation of said multivibrator as it runs free,

auxiliary circuit means coupled between the other output of said multivibrator and the spade electrode at one position in said beam switching tube for extinguishing an electron beam therein after the selected group of pulses has been generated, the extinguishing of the electron beam also disabling said multivibrator, and

setting-selection means coupled to each of the spade electrodes in said beam switching tube for selecting the group of electrodes at which an electron beam will form and thus controlling the number of pulses generated in a group.

7. The circuit defined in claim 6 wherein said auxiliary circuit means includes a connection from the spade electrode at said one position through a pair of diodes connected anode-to-anode to a power source, one output of said multivibrator being connected through a capacitor to the junction of said pair of diodes to couple positive and negative pulses alternately thereto, said spade electrode also being coupled through a load resistor to said power supply.

8. The circuit defined in claim 6 wherein said auxiliary circuit means includes a connection from the spade electrode at said one position through a pair of diodes connected anode-to-anode to a power source, the output of said multivibrator being connected through a capacitor to the junction of said pair of diodes to couple positive and negative pulses alternately thereto, said spade electrode also being coupled through a load resistor to said power supply,

9. A pulse generator circuit including a pulse source having an input circuit and an output circuit and including a control electrode which permits the pulse source to be held in two states, one state in which it is disabled and does not generate pulses, or a second state in which it is free-running and generates pulses,

a multi-position pulse counting circuit which is adapted to be held in two states, one state in which it is energized and can receive and count pulses from said pulse source, or a second state in which it is disabled, said pulse source also being disabled, at the same time,

first means in said counting circuit for energizing it,

a first connection between said pulse counting circuit and said pulse source for rendering said pulse source free-running when the counting circuit is energized, or disabling said pulse source when said counting circuit is disabled,

said counting circuit being coupled to the output of said pulse source and including electrode means for registering the receipt of pulses serially in its positions starting at the first or some intermediate position and terminating at the last position,

second means in said counting circuit for selecting a position at which its counting operation is to start,

disabling circuit means at the last position in said pulsecounting circuit for disabling it when the pulse count reaches said last position, and

a second connection from the output of said pulse source to said disabling circuit means at said last position in said pulse counting circuit for operating said disabling circuit and thus disabling said pulse counting circuit and said pulse source when the pulse count reaches said last position.

10. The circuit defined in claim 9 wherein said disabling circuit includes a pair of diodes connected in series between said last position of said counting circuit and a source of bias voltage, and the junction of said diodes is capacitively coupled to said second connection from the output of said pulse source.

11. The circuit defined in claim 9 wherein said first means and said second means comprise electrode means for forming an electron beam and directing it to the selected position at which the counting operation is to start, and

said counting circuit includes means in its coupling to the output of said pulse source for receiving pulses therefrom and moving the electron beam from one position to the next with each pulse received.

12. The circuit defined in claim 9 wherein said first means and said second means comprise electrode means for forming an electron beam and directing it to the selected position at which the counting operation is to start,

said counting circuit includes, in its coupling to the output of said pulse source, means for receiving pulses therefrom and moving the electron beam from one position to the next with each pulse received, and

said disabling circuit includes a pair of diodes connected in series between said last position of said counting circuit and a source of bias voltage, and the junction of said diodes is capacitively coupled to said second connection from the output of said pulse source.

References Cited by the Examiner UNITED STATES PATENTS 2,856,558 10/1958 Cola 315- 3,002,151 9/1961 Broderick et al 328-496 3,158,854 11/1964 Keen et al. 3158.5 X

JAMES W. LAWRENCE, Primary Examiner.

R. SEGAL, Assistant Examiner.

Claims

9. A PULSE GENERATOR CIRCUIT INCLUDING A PULSE SOURCE HAVING AN INPUT CIRCUIT AND AN OUTPUT CIRCUIT AND INCLUDING A CONTROL ELECTRODE WHICH PERMITS THE PULSE SOURCE TO BE HELD IN TWO STATES, ONE STATE IN WHICH IT IS DISABLED AND DOES NOT GENERATE PULSES, OR A SECOND STATE IN WHICH IT IS FREE-RUNNING AND GENERATES PULSES, A MULTI-POSITION PULSE COUNTING CIRCUIT WHICH IS ADAPTED TO BE HELD IN TWO STATES, ONE STATE IN WHICH IT IS ENERGIZED AND CAN RECEIVE AND COUNT PULSES FROM SAID PULSE SOURCE, OR A SECOND STATE IN WHICH IT IS DISABLED, SAID PULSE SOURCE ALSO BEING DISABLED, AT THE SAME TIME, FIRST MEANS IN SAID COUNTING CIRCUIT FOR ENERGIZING IT, A FIRST CONNECTION BETWEEN SAID PULSE COUNTING CIRCUIT AND SAID PULSE SOURCE FOR RENDERING SAID PULSE SOURCE FREE-RUNNING WHEN THE COUNTING CIRCUIT IS ENERGIZED, OR DISABLING SAID PULSE SOURCE WHEN SAID COUNTING CIRCUIT IS DISABLED, SAID COUNTING CIRCUIT BEING COUPLED TO THE OUTPUT OF SAID PULSE SOURCE AND INCLUDING ELECTRODE MEANS FOR REGISTERING THE RECEIPT OF PULSES SERIALLY IN ITS POSITIONS STARTING AT THE FIRST OR SOME INTERMEDIATE POSITION AND TERMINATING AT THE LAST POSITION, SECOND MEANS IN SAID COUNTING CIRCUIT FOR SELECTING A POSITION AT WHICH ITS COUNTING OPERATION IS TO START, DISABLING CIRCUIT MEANS AT THE LAST POSITION IN SAID PULSECOUNTING CIRCUIT FOR DISABLING IT WHEN THE PULSE COUNT REACHES SAID LAST POSITION, AND A SECOND CONNECTION FROM THE OUTPUT OF SAID PULSE SOURCE TO SAID DISABLING CIRCUIT MEANS AT SAID LAST POSITION IN SAID PULSE COUNTING CIRCUIT FOR OPERATING SAID DISABLING CIRCUIT AND THUS DISABLING SAID PULSE COUNTING CIRCUIT AND SAID PULSE SOURCE WHEN THE PULSE COUNT REACHES SAID LAST POSITION.