US2901735A - Magnetic amplifier drive for coincident current switch - Google Patents

Description

Aug. 25, 1959 v J. D. LAWRENCE, JR

MAGNETIC AMPLIFIER DRIVE ECR CCINCIDENT CURRENT SWITCH Filed April 29, 1955 AGENT United States Patent() MAGNETIC AMPLIFIER DRIVE FOR COINCIDENT CURRENT SWITCH Joseph D. Lawrence, Jr., Philadelphia, Pa., assignor, by mesne assignments, to Sperry Rand Corporation, New York, N.Y., a corporation of Delaware Application April 29, 1955, Serial No. 504,916

14 Claims. (Cl. 340-174) This invention relates to coincident current switches. Switches of this type are well known in the prior art but they normally had a drive system utilizing vacuum tubes kas the principal components thereof. There are a number of disadvantages inherent in the vacuum tube type of drive and it is the primary object of this invention to overcome these disadvantages.

I Another object of the invention is to provide a coincident current switch together with a drive -therefor which is an improvement over the prior art arrangements in the same class.

lt is another object of the invention to providea coincident current switch with a drive system of such character that the output pulses of the two drive elements producing the coincidence are accurately timed with respect to each other.

A further obiectvof the invention is to provide a coincident current switch adaptedto be connected in a complete overall computing or data translating system'where 'eration than prior devices of this character.

Other objects and advantages of the invention will become apparent as this description proceeds.v

The invention employs a plurality of horizontal lines each controlled ,by a magnetic amplifier and a plurality of vertical lines each also controlled by a magnetic amplifier. At each intersection of a horizontal and vertical line there is a core which is magnetized by currents owing in the horizontal and vertical lines. There is a bias winding on the core. which normally biases the core to negative saturation. If the coil due to the horizontal line but not the coil due to the vertical line (or vice versa) on the core is energized, it will neutralize the bias winding but the core will remain negatively magnetized. However, if both the horizontal and the vertical lines passing through a given core are energized, the bias will be overcome and the core will be switched to positive saturation. There is an output coil on the core in which `potential is induced whenever the core is switched from negative to positive magnetization or Vice versa. The important novelty of the invention resides in the magnetic ampliiier drive` for the horizontal and vertical lines. Each horizontal line and each vertical line has its own mag- "n'etie' amplifier controlled by its own input so that upon the selection of a given line the magnetic amplifier will ,Y 2,901,735 Patented Aug. 25, 1959 zontal line and a given vertical line are both to be energized, their output pulses will occur simultaneously. By virtue of the magnetic amplifier type of drive,-the aforesaid objects can be achieved.

In the drawings:

Figure 1 is a schematic diagram of one embodiment of the invention.

Figure 2 illustrates one of the cores together with the coils thereon.

Figure 3 s a hysteresis loop for the core material of Figure 2.

Figure 4 is a timing diagram for the square wave alter` nating current generators PP-l and PP-2 of Figure 1.

In Figure l there is a plurality of horizontal lines H and a plurality of vertical lines V. At each crossover there is a core v10. Each horizontal line is a series circuit and includes the coil H on each core 10 of a horizontal row.v Likewise each vertical line is a series circuit and includes the coil V on each core 10 of a vertical column. There is a bias winding B on each core 10 and the bias windings are all connected in series with each other and with a source of bias 29. An output winding O on each core may have a rectifier 28 in series therewith if only unidirectional output signals are desired.

vThe rectier 28 may, of course, be omitted.

Each vertical line has a driving magnetic amplier all of which have been shown schematically but only one of which has reference numbers thereon. The explanation of this one applies to all. The output coil 11 of the magnetic amplifier is in series with its complementary vertical line and lis on a core 9 whose hysteresis loop is substantially rectangular. Power winding 12 on the core is in series with source PP-l which generates a square wave alternating current as shown in Figure 4. There is also a signal winding 13 which is in series with the square .wave alternating current source PP-Z. As shown in Fgure 4, generator PP-2 goes positive during the negative excursions of source PP-l. Due to rectifier 27, only the positive excursions of source PP-2 may flow through rcoil .13 is grounded through any suitable switch 18 or other electrical circuit. This causes the next positive excursion of source PP-Z to drive current through coil 13. This resets the core 9 to negative remanence. During the next positive excursion of source PP-l a positive pulse .will flow through coil 12 Iand drive the core back to positive remanence. This latter action will cause aprapid change in the flux of core 9 and therefore induce a potential in coil 11. This potential is in proper polarity to flow through rectifier 26 to the vertical coils V on each of the cores 10 of the second vertical line of cores. As has already been pointed out, this `action alone is not enough to induce potentials in the output coils O of the cores 10 of the second vertical line. This follows from the fact that the bias current through the bias coils B has not only saturated this core negatively but has applied a very large negative bias of a magnitude illustrated by the vector 30 of Figure 3. The llow of current through the vertical coils V on the cores 10 will exactly counteract the large negative bias 30 and will return the cores'l to negative remanence. But this still does not induce potential in the output coils O as the change of llux is very small when the core moves from negative saturation asomar lto negative remanence, as would be the case here. It follows that all of the cores of the selected vertical line stand at negative remanence except for the one which is in the selected horizontal line. If it now be assumed that the fifth horizontal line from the top is the selected horizontal line, it is noted that it has an input coil 16 in series with source PP-Z. It has an output coil 14 in series with rectifier 17 as well as in series with the fifth horizontal line. The power winding 15 is in series with source PP-l. If the coil 16 were grounded either "through a simple switch or any complex piece of electronic equipment, and if this grounding occurred at approximately the same time that the free end of coil 13 .was grounded, it is noted that the same positive excursion of source PP-Z which reset the core 9 will also ow through coil 16 and reset the core 25 to negative remanence. The next positive excursion of source PP-l will -ow through coil 15 and drive the core 25 back to positive remanence, whereby there is a large rate of change of flux in core 25 and a large induced potential in coil 14. This potential is in proper direction to drive current Zthrough rectifier 17 and thence through the fifth horizontal line including all of the coils H on the cores 10 of that horizontal line. Therefore, the particular core 23 which happens to be in both the selected vertical line and the selected horizontal line, will have currents flowing in coils H and V thereon and since both of these currents are substantially equal and opposite to the bias current flowing in coil B, the bias current is more than overcome and the core is driven rapidly to positive saturation. In going from negative to positive saturation it passes across an unsaturated portion of the hysteresis loop and therefore there is a rapid change of fiux which induces a large output potential in the output coil O. The cores 9, 10 and 25 hereinabove mentioned, as well as all of ,the other cores, preferably, though not necessarily, should be of any well known material which gives a substantially rectangular hysteresis loop. Examples of suitable materials are Orthonik and 4-79 Moly-Permalloy.

In summary, it is clear that an output signal from any desired one of the numerous output coils O can be produced by substantially concurrently energizing the inputs Vof the magnetic amplifiers that respectively feed the horizontal and vertical lines which cross-over at the core for the selected output coil O.

I claim to have invented:

1. In a coincident current switch, a core of magnetic material, biasing means for applying a biasing magnetizing force to the core in one direction, an output winding on the core, a first magnetic amplifier, core magnetizing means responsive to the output or" the first magnetic amplifier for applying a magnetizing force to the core in a direction opposite to that of the biasing means, a second magnetic amplifier, and core magneticing means responsive to the output of the second magnetic amplifier for applying a magnetizing force to the core in a direction opposite to that of said biasing means, each of said first and second magnetic amplifiers having an input winding and a power winding, a first source of power pulses coupled to the power windings of both said first and second amplifiers whereby said amplifiers are energized by said first source in synchronism with one another, a second source of control pulses, and means for selectively coupling pulses from said second source to the input windings of said first and second amplifiers whereby input signals are selectively applied to said amplifiers from said second source in synchronism with one another, each of said amplifiers including means responsive to an input signal applied thereto for producing an output.

2. A coincident current switch comprising a first group of magnetic amplifiers each having control means4 for controlling the output of the amplifier, a group of cores for each of said first magnetic amplifiers, each of said first magnetic amplifiers having output means for selectively applying a magnetizing force to each core of the group associated with said amplifier, a second group of .4 magnetic amplifiers each having control means for controlling the output of the amplifier, each magnetic amplifier of the second group having output means for selectively applying to a group of said cores a magnetizing force additive to any magnetizing force applied by said first amplifiers, each of said first and second magnetic amplifiers including a power winding thereon, means interconnecting the power windings of said first and second groups of magnetic amplifiers, a source of spaced energizing pulses coupled to said interconnected power windings whereby the amplifiers in both said first and second groups are energized in synchronism with one another by pulses from said source thereby to synchronize the selective outputs of said first and second amplifiers, means for applying a biasing magnetizing force to all of said cores in a direction opposing all of the previously mentioned magnetizing forces, said biasing magnetizing force being of such magnitude that each core remains in a saturated region of its hysteresis loop unless at least two of said additive synchronized magnetizing forces are applied to it in which event it will move along an unsaturated portion of its hysteresis loop thereby effecting a substantial rate of change of flux in the core, each core having an output winding thereon in which potential is induced when the flux therethrough changes.

3. A coincident current switch as defined in claim 2 in which each magnetic amplifier includes, in addition to said power winding, a core of magnetic material exhibiting a substantially rectangular hysteresis loop, an output coil on the core, and a control winding on the core.

4, A coincident current switch comprising a plurality of horizontal lines, a plurality of vertical lines which cross all of the horizontal lines, a core at each crossover, means in each horizontal line for applying a magnetizing force to each core along the line, means in each /ertical line for applying a magnetizing force additive to any previously recited magnetizing force to each core along the line, a rectifier in each horizontal line, a rectifier in each vertical line, means for applying normal potentials to all of the rectifiers to bias them to cut off, a magnetic amplifier in each horizontal line, a magnetic amplifier in each vertical line, pulse generator means for applying power pulses synchronously to all the magnetic amplifiers, each magnet amplifier having control means to control its output and including means whereby when its control means is controlled to effect a pulse output from the amplifier that a pulse appears on the line associated with the amplifier and overcomes the bias on the rectifier in that line so as to cause a fiow of current in the line to thereby apply magnetizing forces to all of .the cores associated with that particular line, and biasing magnetizing means for applying a biasing magnetizing force to all of said cores in a direction opposite the previously mentioned magnetizing forces and of such magnitude as to drive the cores to saturation region eX- cept when at least two of said additive magnetizing forces -concurrently are applied to a core in which latter event the core will be driven from said saturation region along an unsaturated portion of its hysteresis loop, and output means associated with each core responsive to the changes of flux therein.

5. A coincident current switch as defined in claim 4 in which each magnetic amplifier has a core, an output coil on the core in series with its associated line, a control winding on the core, and a power winding connected to said pulse generator means.

6. A coincident current switching system comprising a plurality of horizontal lines, a plurality of vertical lines each of which crosses all of the horizontal lines, a core at each cross-over, means in each horizontal line for applying a magnetizing force to each core along the line, means in each vertical line for applying a magnetizing force additive to any previously recited magnetizing force to each core along the line, a rectifier in each horizontal line, a rectifier each vertical line', 'means for applying nll p'tentials' t0 all 0f- 'Said TCe'S ibla'sihei t0 Cut off, a magnetic amplifier in each horizontal line, a magnetic amplifier in each vertical line, each magnetic amplifier having a core with control, power and output windings thereon, rst pulse means coupled to each of said power windings for supplying spaced synchronized pulses to each of said powerwindings, second pulse means for applying synchronized control pulses to selected ones of said control windings during-the spaces between the first-named pulses, and biasing magnetizing means for applying a biasing magnetizing force to all of said cores in a direction opposite to the previously mentioned magnetizing forces and of such magnitude as to drive the core to saturation region except when at least two of said additivc magnetizing forces concurrently are applied to a core in which latter event the core will be driven from said saturation region along an unsaturated portion of its hysteresis loop, and output means responsive to the conditions of the cores.

7. A coincident current switch as defined in claim 6 in which the output means includes a coil on each core.

8. In combination, a plurality of magnetic cores, a first group of drive lines coupled to said cores in a first orientation, a second group of drive lines coupled to said cores in a second orientation, each of said cores being responsive to simultaneous drive on drive lines coupled thereto in both said orientations and being substantially non-responsive to drive on drive lines coupled thereto in one only of said orientations, and means for selecting lines and for effecting synchronized drive on selected lines in both said orientations comprising a first group of pulse-type magnetic amplifiers having outputs coupled respectively to said first group of drive lines, a second group of pulse-type magnetic amplifiers having outputs coupled respectively to said second group of drive lines, each of said amplifiers in said first and second groups of amplifiers having means for applying input signals to said amplifier a power winding for applying power energization to said amplifier, means interconnecting the power windings of each of said groups of amplifiers to one another and to the power windings of the other group of amplifiers, and a source of spaced power pulses coupled to said interconnected power windings for synchronously energizing the power windings of both said first and second groups of amplifiers.

9. The combination of claim 8 wherein the power windings of said first and second amplifier groups are connected in series with one another.

10. In combination, a plurality of magnetic cores, a first group of drive lines coupled to said cores in a first orientation, a second group of drive lines coupled to said cores in a second orientation, each of said cores being responsive to simultaneous drive on drive lines coupled thereto in both said orientations and being substantially non-responsive to drive on drive lines coupled thereto in one only of said orientations, and means for selecting lines and for effecting synchronized drive on selected lines in both said orientations comprising a first group of pulse-type magnetic amplifiers having outputs coupled respectively to said first group of drive lines, a second group of pulse-type magnetic amplifiers having outputs coupled respectively to said second group of drive lines, each of said amplifiers in said first and second groups of amplifiers having a power winding for applying power energization to said amplifier, means interconnecting the power windings of each of said groups of amplifiers to one another and to the power windings of the other group of amplifiers, a source of spaced power pulses coupled to said interconnected power windings for synchronously energizing the power windings of both said first and second groups of amplifiers an input winding on each of said ampliers for controlling the output of said amplifier, a further source of pulses producing pulses in the spaces between said spaced power pulses,

'6 and control means for coupling pulses from said further pulse source to selected ones of said input windings, whereby said selected input windings are synchronously controlled by input pulses occurring between the times of occurrence of said spaced'power pulses.

ll. In combination, a plurality ofmagneticcores, a first group of drive lines coupled to said cores in a first orientation, a second' group of drive lines coupled to said cores in a second orientation, each of'said cores being responsive to simultaneous drive on drive lines coupled thereto in both saidorientat-ions' and being substantially non-responsive to drive on drive lines coupled thereto in one only of said orientations, and means for selecting lines and for effecting synchronized drive on selected lines in both said orientations comprising a first group of pulse-type magnetic amplifiers having outputs coupled respectively to said first group of drive lines, a second group of pulse-type magnetic amplifiers having outputs coupled respectively to said second group of drive lines, each of said amplifiers in said first and second groups of amplifiers having a power winding for applying power energization to said amplifier, means interconnecting the power windings of each of said groups of amplifiers to one 'another and to the power windings of the other group of amplifiers, a source of spaced power pulses coupled to said interconnected power windings for synchronously energizing the power windings of both said rst and second groups of amplifiers an input winding on each of said ampliers for controlling the output of said amplifiers, a further source of pulses producing pulses in the spaces between said spaced power pulses, and control means for coupling pulses from said further pulse source to selected ones of said input windings, whereby said selected input windings are synchronously controlled by input pulses occurring between the times of occurrence of said spaced power pulses, said control means including means for connecting selected ones of said input windings in parallel across said further source of pulses.

l2. In combination, a plurality of magnetic cores, a first group of drive lines coupled to said cores, a second group of drive lines coupled to said cores, each of said cores having a drive threshold characteristic which is exceeded by simultaneous` drive from both said groups and which is greater than a drive from one only of said groups, and means for selecting a drive line from each of said groups and for driving synchronously selected lines in both of said groups, said selecting and driving means comprising a first group of pulse-type magnetic amplifiers having outputs coupled respectively to said first group of drive lines, a second group of pulse type magnetic amplifiers having outputs coupled respectively to said second group of drive lines, each of said amplifiers in said first and second groups of amplifiers having a power winding coupled to the amplifier output, and an input winding for controlling the output drive of said amplifier, means interconnecting the power windings of each of said groups of amplifiers to one another and to the power windings of the other group of amplifiers, and a source of spaced power pulses coupled to said interconnected power windings for synchronously energizing the power windings of both said first and said second groups of amplifiers.

13. The combination of claim l0 and further including a further source of pulses producing other pulses in the spaces vbetween said spaced power pulses, and control means for coupling said further pulse source to selected ones of said input windings, whereby said selected input windings are synchronously energized by said other pulses.

14. In combination, a plurality of cores each of which comprises magnetic material capable of assuming stable remanence conditions, means for applying a biasing magnetizing force to said cores in a rst direction, and means for applying a magnetizing force to said cores in a direction opposite to that of said biasing force, said force applying means comprising first and second pluralities of idrivelines coupled to said cores, one drive line from each of said rst and second pluralities being coupled to each core, rst and second pluralities of magnetic ampliers coupled respectively to said first and second pluralities of drive lines, each of said amplifiers including an input winding and a power winding, a source of control -pulses, means for selectively translating pulses from said vcontrol pulse source to the input windings of said ampli- ,iiers so that input pulses are applied to selected ones of said irst and second pluralities of amplifiers in synchronism with one another, and a source of power pulses V8 coupled to all of said power windings so that the ampli; ers are energized by said power pulse source in synchronism with one another.

' References Cited in the le of this patent UNITED STATES PATENTS 2,709,248 Rosenberg May 24, 1955 2,734,184 Rajchman Feb. 7, 1956 10 2,734,187 Rajchman Feb. 7, 1956 UNITED STATES PATENT OFFICE CERTIFICATE OE CORRECTION Patent Noo 2,901,735 August 25, 1959 Joseph D., Lawrence, Jr.,

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 3, line 53, for "magnetieing" read magnetizing Column 4, line 44, forv "magnet amplifier" read M- magnetie amplifier mx; column 6, lineI 63, for the Claim reference numeral "lO" read e l2 nu.,

Signed and sealed this 29th day of March l960o (SEAL) Attest:

KARL H., AXLINE ROBERT C. WATSON Attesting OHcer Commissioner of Patents

Images