US2418521A

US2418521A - Impulse measuring device

Info

Publication number: US2418521A
Application number: US571880A
Authority: US
Inventors: George A Morton; Leslie E Flory
Original assignee: RCA Corp
Current assignee: RCA Corp
Priority date: 1943-01-21
Filing date: 1945-01-08
Publication date: 1947-04-08
Anticipated expiration: 1964-04-08

Description

April 8, 1947.

e L 016/ I 17703 G. A. MORTON ETAL IMPULSE MEASURING DEVICE Original Filed Jan. 21, 1943 2 an H) Clem/7' 4- :w/rc'M/va anew/r 54 IN V EN TOR 5. 6E0! A. MORE/V Y 8' Lea/5 E. FLO/2y Patented Apr. 8, 1947 IMPULSE MEASURING DEVICE George A. Morton and Leslie E. Flory, Princeton,

N. J., assignors to Radio Corporation of America, a corporation of Delaware )riginal application January 21, 1943, Serial No.

473,146, now Patent No. 1946. Divided and this 1945, Serial No. 571,880

Claims. (Cl. 177-9353) vention to the various circuits to be described is the well known trigger circuit of the general type described in "Theory and Application of Vacuum Tubes, by Herbert J. Reich. In one of its simplest forms, this trigger circuit includes two triodes in which the grid of the first triode is coupled to the anode of the second triode through a network comprising a parallel connected resistor and capacitor, and the grid of the second triode is similarly coupled to the anode of the first triode through a similar coupling network. The cathodes of both triodes are grounded, either directly, or through suitable cathode resistors. Grid and anode potentials are,

applied to the respective electrodes through separate resistors, If desired, a gaseous discharge tube may be connected across one of the anode resistors to indicate circuit operation.

In operation, if a negative voltage is applied to the grid of the first triode, the anode current of the triode will be reduced and the anode potential will become more positive. Due to the connection through the coupling resistor, the grid potential of the second triode will become more positive, causing an increase in the anode current of the second triode, with a resultant decrease in the second triode anode potential. This decrease in anode potential will, in turn,

cause the grid potential of the first triode to become more negative. This action will continue until the anode current of the first triode is cut off. The first triode will remain cut oil, and the second triode will remain conducting, until a positive potential is applied to the grid of the first triode or a negative potential is applied to the grid of the second triode. In either latter in- .stance, the tube operating conditions will be reversed and the first triode will become conducting and the anode current of the second triode will be cut off.

One of the features of the instant invention is the utilization of such trigger circuits in cas- 2,404,047, dated July 16, application January 8,

cade arrangement, whereby a predetermined change in the polarization or actlvization of one triode of the trigger circuit will generate a pulse to trigger or activate a succeeding trigger circuit in the cascade arrangement. As many trigger circuits as desired may be connected in cascade.

The present invention has for its principal object the provision of an improved apparatus and method of operation whereby predetermined numbers of electrical impulses are transmitted from a continuously operating constant frequency source to an electronic computer or other utilization device.

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:

Figure l is a block diagram of a preferred embod ment of the invention, and

Figure 2 is a wiring diagram of this embodiment.-

Fig. 1 provides a general means for deriving a predetermined number of stepping pulses in rapid succession upon application thereto of an initial starting voltage.

A source of oscillations 80, of Waveform 8|, is connected through a pulse shaping circuit 82 to provide sharply defined negative pulses 83. These negative pulses are then applied simultaneously, through a switch s4, to a delay circuit 84 and a switching circuit 85, such as a multivibrator.- The switching circuit, in response to the initial negative pulse applied thereto, provides a positive bias potential to unblock an amplifier 86. After the amplifier 86 is unblocked, the delayed pulses are applied through the delay circuit 84 to the amplifier input circuit. The output circuit of the amplifier is next applied to an electronic counter 81, which may be of the general type described in the copending U. S. application of Leslie E. Flory, Serial No. 467,032, filed November 28, 1942, in which any predetermined number of pulses applied thereto willprovide a control potential when the counter is filled.

When the desired number of pulses are counted.

the control potential derived from the counter is applied to the ampl fier to bias oft the amplifier anode current. Thus a predetermined number of pulses may be delivered to a load circuit connected to the amplifier output circuit. The number of pulses may be controlled by changing the electronic counter as described in the copending Flory application. The circuit may be cleared for a succeeding operation by disconnecting or electronic counter. to restore the counter to any predetermi'nedinitial count. it should be under- As hereinafter explained in connection with Fig. 2, the delay circuit 84 may bea conventional.

slideback trigger circuit having grid resistors of different values such that it has only one stable operating condition. The values of these grid put the amplifier 88 in a conducting condition,

but (2) returns to its stable operating condition before the second or next successive pulse applied irom the pulse shaper 82. Each time the slideback trigger circuit returns to its stable operating condition, the second control grid of the amplifier 86 is made more positive and a counting pulse is applied to the counter 81.

Fig. 2 provides a specific circuit for the operation generally described in Fig. 1. The oscillator 88 is of the conventional M type. Its output circuit is connected through the conventional pulse shaping circuit 82 to provide the discrete negative pulses 83. The negative pulses are then simultaneously applied to key the switching multivibrator 85 which is a symmetrical trigger circuit of the type described heretofore, and to key the slideback trigger circuit 84 which provides the required delay for the pulses applied to the second control electrode of the amplifier tube 86. A positive bias potential is derived from the switching multivibrator 85 which has its current conductivity changed from its left to its right side in response to actuation thereof by the initial negative pulse. This positive bias potential is applied to the first control electrode of the'amplifier tube 86 to unblock the tube for amplification of the delayed pulses. The minimum delay time of the slideback trigger circuit 88 must be sufiicient to allow the switch 85 to put the amplifier 88 in a conducting'condition. This is necessary to prevent the delayed pulse being applied to the amplifier before the amphfier isin condition to pass it.

The maximum delay time must be short enough to allow the delay circuit 84 to resume its normal stable operating condition before the next succeeding pulse is applied. Thus each time the delay circuit 84 returns to its stable operating condition with its left side conducting, a pulse is applied through the amplifier 88 to the counter 81.

The anode circuit of the amplifier 88 is connected to the electronic counter 81 which includes the

trigger circuits

88, 89, 90, 9|, 82 connected to provide a control potential when a predetermined number of pulses have been counted. In the particular circuit disclosed, operation of the switch 83 will provide a control pulse for either six or fourteen applied pulses from the amplifier 86. The control potential is derived from the movable element of the switch s3 and applied to the first control electrode of the amplifier 86 to block the tube anode current. The number of pulses required for the control potential depends upon the particular trigger circuit connected to the movable elements ofthe switch s3. The predetermined number of pulses are then derived from the amplifieranode circuit and applied to the utilization circuit.

The pulse generator may be cleared by opening the switches sl and s5. Opening the switch s4 removes the source of oscillations from the counting circuit, 'while opening the switch s5 changes the bias on all trigger circuits oi. the

stood that the essential difference between the counter of Fig. 2 and the counter circuit disclosed in the copending Flory U. S. application referred to heretofore, is that in the instant device the initial cbunt is provided by reversed bias means in one or more predetermined trigger circuits, (in this instance, trigger circuit 89), while feedback means are provided in the copending application.

All trigger circuits may be cleared, after each multiplying operation is completed, by applying a high negative control electrode bias simultaneously to allbinary I tubes in the manner which is described, for example, in the copending application mentioned heretofore, or by removing the grid bias from the binary 0 tubes.

It should be understood that the particular circuits described are merely illustrative 01' one means for accomplishing the invention. Many of the individual circuits may be modified, and the coupling and control circuits varied in accordance with accepted engineering practice, without deviating from the spirit and scope of the invention.

We claim as our invention:

1. A circuit for generating a predetermined number of voltage pulses which includes a source of oscillations, a blocking amplifier, means responsive to said oscillations for initially unblocking said amplifier, means responsive to said oscillations for delaying said oscillations until said amplifier is unblocked and for applying said delayed oscillations to said amplifier, an electronic counter, means for applying said delayed and amplified oscillations to actuate said counter, means for deriving a control potential from said counter when a predetermined number 0! oscillations have been counted thereon, means for applying said control potential to block said amplifier, and means for deriving said pulses from said amplifier.

2. A circuit for generating a predetermined number of voltage pulses which includes a source of oscillations, a blocking amplifier, means mcluding a trigger circuit responsive to said oscillations for initially unblocking said amplifier, means responsive to said oscillations for delaying said oscillations until said amplifier is unblocked and for applying said delayed oscillations to said amplifier, an electronic counter, means tor applying said delayed and amplified oscillations to actuate said counter, means for deriving a control potential from said counter when a predetermined number or oscillations have been clllations for delaying said oscillations until said amplifier is unblocked and for applying said delayed oscillations to said amplifier, an electronic counter, means for applying said delayed and amplified oscillations to actuate said counter,

means for deriving a. control potential from said counter when a predetermined number of oscil'-' lations have been counted thereon, means for applying said control potential to block said ampiiner, and means for deriving said pulses from counter and said unblocking means after each said amplifier. derivation of said pulses.

4. A circuit for generating a predetermined number of voltage pulses which includes a source GEORGE A. MORTON. of oscillations, a blocking amplifier, means in- 5 LESLIE E. FLORY. eluding a trigger circuit responsive to said oscillations for initially unblocking said amplifier, REFERENCES CITED trigger circuit delay means resmnsive Said The followin references are oi record in the oscillations for delaying said oscillations until me of this paint: said amplifier is unblocked and for applying said 10 delayed oscillations to said amplifier, an elec- UNITED'STATES PATENTS tronic counter comprising a plurality of trigger Number Name t circ it m n for pp ying said delayed and am- 2,373,134 Massonneau Apr. 10, 1945' plifled oscillations to actuate said counter, means 2,153,235 K May 1 ,1939 for deriving a control potential from said counter 15 2,310,105 Michel b, 2, 1943 when a pretdeetermined number of oscillations have 2,332,300 c k a t, 19, 1943 been coun d thereon, means for applying said control potential to block said amplifier, and FOREIGN PATENTS means for deriving said pulses from said amplifier. N m r Country Date 5. Apparatus of the type'descrlbed in claim 1 20 485,703 British May 24, 1938 including bias means for clearing said electronic 355,705 British Aug. 24, 1931