US2943311A - Analog-to-digital translator - Google Patents

Description

June 28, 1960 G. D. HULST 2,943,311

ANALoG-ToDIGITAL 'rRANsLAToR Filed Jan. '7. 1957 RAT/0 las la Y is? ILL' 29 Inventor 6501966' HJ A ltorne y United States Patent@ 2 Claims. (Cl. 340-347) This invention relates -generally to analogftordigital translation devices and in particular to .a.dev1ceyfor translatingthe value of angular shaft positions into coded Y electrical pulses.

Inanalog-to-digital translation devices,`\it becomes necessary to channel the energy pulses fromthe shaft yread-out elements tosome means which is eapablelof translating these pulses into` the language of the machine forcomputation `or storage purposes. In the priorart,

. such a. translation has been accomplished by means of banks of relays or switching matrices. The use of banks off relays in the prior artinvolved holding circuits which e were operatedfor switching .advantage `by having `one relaydrop out another relay as the first relay was picked.

e There very often is aV chain reaction with thisarrangement or a series of relay actions, to wit: pickingholdingand l dropping, for a singlejdata bit change. --It is obviousthat lower Vordered wheel 'is .,arrangedto be. operative in conjunctionwitha control brush for a certain portion such a chain reaction of the relays results inv relatively y slow operation and a requisite sensitive timing.

jIt also has been necessaryin the .translation operation to assure a non-ambiguous read-out from the shaft elements'. ForV instance, in readingwout thenumbers 39,.V 40

`and 31 and assuming a separate read-out positoin forthe units and tens position, it is conceivable that flthe brushes did not read exactly together, butinstead Vone brushled ythe other,'the translation, mightl read 39, 30, 40 and 41 V0139, 49, 40 and'41. To overcomethis problem, there isbrought into use the lead and the llag brush. `The lead Vand lag brushes are set'respectivelyefar ahead yandfar behind the normal read-outa point; and by readingfrom ,the lag brush up to a .carry v.time yancl fromvtheglead' brush' at and beyond the carry time, there is iinsured a non-ambiguous read-out. It is clear that toaccomplish the lead and lag read-out there must be a'controlling device. In certain translation devices the controls are accomplished by having conductive'strtips .ofl80 degrees added to the shafts. commutator straps and having the read-out pass through jth'ese relays, Ait, is possible to `have either lead or lag readout for one-half the shaft rotation. f* jIt also becomes clear that the above-mentionedv commutator, strap, withjits inherent mechanical characteristics in combination with the By controlling relays with these relays, gives rise to considerations of mechanical toler?vv ance and speedlimitations, the-improvement lof which is desirable for the higher speed operations such as those desired in analog computers or high-speed control systems.

It is therefore the object of this invention to provide an improved analog-to-digital translation device.

It is a further object of this invention to provide a translation device which provides an output `digital change of one or one bit by means of transferring only one relay.

It is a further object of this invention to provide a translation device wherein the tolerances for the read-out means associated with the shaft rotating elements is not critical.

In accordance with the above objects the invention time to accomplish the change. to, addvgan additional singledigit value or dropped out to add avsingledigitrvalue depending von its energized or rdeenergizedstatus before the addition is sensed. The

.and las madam mntrol 2,943,31 l Patented June 28, 1960 ICC ,features ,logical relay-circuitry which provides for adding or subtracting from-thetranslation answer one digit value at a Atime While only requiring one relay operation at a A relay may be picked invention further features coded Wheels attached to the -shaftwwhich serves as aY primary source of shaft position information. lAnadditional feature ofthe invention is -the provision of leadand lag readout means to insure a nonfambiguous readout. YIn conjunction with the coded -,wheels and the leadand lag readout the `invention further l,features :that-theV code inscription itself serves as a control forthe lead Aandlag readout. VConductive material on a of .the lower ordered -Wheels rotation to effect a lead As higher ordered wheels are added to Ytheydevicehthe lower orderedwheels act in this control; capacity` aswell as a` source of shaft angular -positioninformatiom 4 The aboveY mentioned and other features and objects of Athis invention'will beeomemovre apparent by reference to thefollowing descriptiontaken in conjunction with the ac companyingdrawing inrwh-ich the figure isa combination schematic `and circuit representation of an analog-to! digital `translation device.

in ,thepiigurethereareeshown'two code wheels 11 and 1,2. Oncode wheel 11 there is aset of read-out brushes -13. On code wheel '12 therekis a vset of lead read-out "brushesg14, and a setv'of lag read-out brushes 15. The index relay icoil 16Vis vconnected to the read-out brush 17. VThe movable contacts 18- are connected mechanically vvith andactuated by the relayr coil 16. The relay coils 19' through 27 are connected through the movable contactsgllalnd points 28 to they lead and lagreadout bru shes14 and 15. "Ihe relay points 29 are coupled to the read-out voltage source 30 and to the output means 31,shownxas 'light' bulbs -in the figure reading in binary number notation. Amore comprehensive understanding 1` of the invention `will result from the following discussion taken in ,coniunction with the figure.

' The .tigure showsfthedevicereadingSll. On wheel 11 only;brush-17 is-resting on conductive material. A circuit Vfrom the read-insupply y32, to junction 33, to conductive strip 34, throughf.brushu 17, through coil 16, to

,the Vother sideof .the supply 32 causes coil 16 to be energized. Withcoil16 energized,y the movable contacts ,-18 .are attractedto ,rest on the normally open points of 28. Onl wheel 12 theonlyread-out brush onythe conductive material isbrush 35. A circuit from the read-in supply 32,through junction 33, to :segment 36, through ...brush 35, through Enormally.open, point 37, through coil mi.Y

` ,co il.,27 and thustransfer the movable contacts 38 and 39. with movablecontacts 38 and 39 transferred, all the bulbs VUare illuminatedLwhiichresultsin a device reading addi- 27, to` lthe other side of thesupplyZ serves to energize tively, in binary numbers, the value 511. As the wheels 11 and 12 rotate clockwise, the brush 17 moves off the segment 34, and the relay coil 16 becomes deenergized dropping out the movable contacts 18. The transfer of the movable contacts 18 results `in the deenergizaton of coil 27 which, in turn, causes the movable contacts 38 and 39 to shift to their unenergized position. With the transferred. With the straps 42 and 43 resting on the normally open side, the light bulb number l1 is illuminated, giving a correct reading of the Shaft position.

* By following the rotation of Wheel 11 and noting the the number 2 bulb is glowing, relay 19 is -still energized;

and as wheel 11 approaches the value 3, relay 19 is deenergized. With the deenergization of relay 19 and the dropping out of the movable contacts 42 and 43, the bulb 1 is again illuminated, thus having bulbs 1 and 2 glowing at the same time to give the correct additive answer of -l|2==3, This circuitry pattern follows, and the next significant step in the discussion occurs at the time that wheel 11 reaches the value 16. When wheel 11 reaches the value 16, brush 17 makes contact vwith the conductive material at 46 rand thereby causes relay coil 16 to be energized. v'At' this saine-"time, wheel P12 has moved to a position where brush 47 is making contact with the conductivey segment at 48. Coil 16 having been energized,-the *st-raps -13 are transferred and brush 47 ureads out through' the' normally open point 49 and the relay coil 23 is'energized to light up bulb 16. As wheel "11 continues to rotate until brush 17 leaves the segment 'at 34, wheel 12 will have moved into a position where brushes 48,50 and 51 will be on the conductive segment. When brush 17 Yleaves the segment 34- and coil 16 is dethe readout from said lirst wheel between said lead and 1. A translation device for translating angular shaft positions into coded electrical pulses comprising an input shaft, iirst and second c'ode wheels, means coupling said code wheels to said shaft for rotation therewith whereby said first code wheel rotates a smaller amount than said second code wheel for the' same amount of shaft rotation, lead and lag readout means coupled with said rSt spending code wheel, and' each assigned a different order of value, each output relay having a pair of movable contacts, each of said movable contacts having an associated normally open point and normally closed point, connecting means associated with each output relay coupling the normally associated open point of one of said movable contacts to the normally associated closed point of the other of said movable contacts, logical circuitry means coupling each of said movable contacts to an associated one of said connecting means of the next higher ordered output relay, and circuitry means coupling said logical circuitry means between said output means and both said single and said lead and lag readout means to effect a change of one digit value in said translation output by a single transfer of said movable contacts.

2. A translation device for translating angular shaft positions into coded electrical pulses comprising an input shaft, first and second code wheels, means coupling said code wheels to said shaft forrotation therewith whereby said iirst code wheel rotates a smaller amount than said second code wheel for the same amount offshaft rotap tion, lead and lag readout brushes coupled with said rst ,code wheel, single readout brushes coupled with said sec'- ond code wheel, a transfer relay with a plurality of normally open points, normally closed points and movable contacts, said transfer relay points coupled to said leadlag brushes whereby each pair of lead-lag brushes for any coded bit is coupled to the normally open and normally closed points associated with a particular movable contact, a transfer relay control circuit coupled to said single set of readout brushes to control the transfer of lag readout brushes for a particular angular rotation of said second wheel, a pluralityof devices for representing said shaft angular positions in coded form, a plurality of output relays arranged in two groups, each group coupled respectively to a corresponding code wheel, and each assigned a different order of value, each output relay having a pair of movable contacts, each of said movable contacts having an associated normally open point and Vnormally closed point, connecting means associated with each output relay coupling the normally associated open point of one of said movable contactsV to the normally associated closed point of the other of said movable contacts, logical circuitry means coupling each of said movable contacts to an associated one of said connecting means of the next higher ordered output relay, and cird cuitry means coupling said logical circuitry means between Ysaid means and both said single andIV said lead-lag readout means to elfect a change of one digit value lin said trans- Electronic Equipment, August 1955, page 13. Y

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