A High-Performance Magnetostriction-Sonic Delay Line

c

L

h HIGH-ERFORMANCE MAGNIZTOSTRICTION-SONIC DELAY LINE

Herman Epstein and Osczr B Stram Burroughs Research Center

Paoli Pennsylvania

summary -- The magnetostriction-sonic delay line described can be used to defi- nite advantage i n applications where extremely short resolution time is WeceSSW This inexqensive high-performance line consists of transducer coils and thin-walled nickel tubing The construction and design result in a rugged de lay l ine with a r e l a t ive ly small inser t ion l o s s a comparatively long contjnuously adjustable delay and a r e l a t ive ly small temperature dependence A simplified theory of operation is discussed and a laboratory model incorpo- r a t h g the fea tures of the de lay l ine is described Consideration is given t o opt imal design o f the components and some applications are offered

I h ~ O D U C T I O N

A magnetostrict on-soat- delay line i s but one configuration of tne general c lass i f icat ior of sonic delay lines which include mercury and quartz delay lines A sonic de lay l ine i s composed of a transmitting transducer and a receiving transducer separated by an e l a s t i c body which might be cal led the sonic delay element o r jus t the de lay element The transmitting transducer cdnverts e l ec t r i ca l s igna l s i n to mechanical vibrations which t raverse the delay

b $

element a t the propogation velocity o f the bulk material (ignoring second order effects which are dependent upon the geometry o f the delay element) When the vibrations reach the receiving cransducer after some time duration the mechanical vibratl ons are reconver ted in to e lec t r ica l signals The slower ve loc i t i e s I

of mechanical d i s t u r b a x e s i n e l a s t i c media as compared wi th the ve loc i t ies of e lec t r ica l signals make possible longer delays i n a smaller device A simple magnetostriction delay line can be made by wrapping c o i l s of wire at two points on a tube (rod o r ribbon) of nickel or any other material having magnetostrictive properties A 2agnet or some other source of biasing magnetic f l u x must be provided a t the rece iv ing co i l The operation of a simple magnetostriction- Sonic delay l ine such as i s shown i n Fig 1 Kill be described below

l

Previous work (l) using f i l a m e n t q delay elements has shown t h a t t h e following characteristics are inherent in the magnetostr ic t ive delay l ine

1 Comparatlvely long delay times-are p o s s i b l e i n a s m a l l package 2 The reset time (resolution) i s independent of t o t a l delay 3 Operation with a ca r r i e r i s unnecessary

5 The de lay l ine is free of jitter or var ia t ion in de lay time The delay can be made coDtinuously adjustable when desired

C I except as caused by temperature ~ 6 The inser t ion l o s s i s no more than 40 t o b0 decibels

The authors undertook the task of developing a magnetostrictive delay capable of a m a w delay of about 250 microseconds with an extended

ampgh-frequency resFonse The nickel tubing f inal ly selected for the delay

btmction methods The necessary receiving and transmitt ing transducers

--

was rugged and inexpensive and l e n t i t se l f readi ly t o common con- s

TRANSDUCER RECEIVING

TRANSMITTING TRANSDUCER ampBIASING MAGNET

MEANS OF ECHO ELEMENT SUPPRESSION

GROUND

Fig l - Schematic representation of a typi- c a l magnetostriction delay l ine

were designed t o work with t h i s tubing and a sui table method of echo suppression was devised The resulting magnetostriction-sonic delay line had three main features in addition t o the charac te r i s t ics mentioned above

1 It operated with pulses of the order of one microsecond duration 2 The signal-to-noise ratio was a t l e a s t 10l 3 Pulse information was stored at a clock frequency as great as

6 9 kc -

Depending upon the frequency response t h a t is required i n a given in- dance two possible forms of the delay element have been evolved I n ap- p l i ca t ions fo r which the resolution requirements are not stringent it i s advantageous t o use a nickel tube of approximately 0125 inch OD because of t h e r i g i d i t y and the consequent simplicity of construction of the whole dedce If it i s desirable to obtain the maxFrmLm possible resolution con- sistent wlth the rserious l imitations that eddy-current losses impose upon the frequency response it is necessary t o decrease the diameter of the tubing

Q

It will be shown that tubing of OmObs inch OD gives a frequency response of at l e a s t up t o t h e lhit imposed by the eddy-current losses a lso that further decrease i n diameter or the subst i tut ion of filamentary ribbon or wire-shaped elements i s not profitable since the improvement i n frequency response is balanced by extreme f r a g i l i t y and- d i f f i cu l ty i n construction The character is t ics of delay l inea having the two possible forms are compared Fn Table I

lEDeuroE OF OPERATION

The operation of the delay line depe-ds upon three basic phenomna (see Fig 1) the insertion of pulses in an e l a s t i c m e d i u m by means of the Joule magnetostrictive effect the propagation o f sonic energy i n the e las t ic medium and the reception of the pulses by means of the V i l l a r i magnetostric- t ive effect

The Joule effect refers ta a change of physical dimensions with the application of magnetic flux A material which expands with the application of flux i s sa id t o have a positive magnetostrictive coefficient a material

2

TABU I

Characterist ics cf Slotted a d Unslotted Tubing

Characteristic r lelay per inch

lnput pulse o juration

Sutput pulse h r a t i o n

T o t a l duration iisturbance

Measured minimum resolving time

Iksertion loss

Attenuation in the nickel tube

Signal-to-noise -atio

kasured varia- ion i n delay d t h temperature

ulse Circulation

Delay Element

Slotted 0125 inch OD tube 0004 inch w a l l

527 microseconds

Between 1 2nd 3 nricroseconds optimum pulse width 25 microseconds

Never less than 25 micro- secor-ds

10 microseconds

28 microseconds

40 db t o 60 db

6 db100 microseconds

Up t o 1Ol (depending upon the damping r e s i s t o r across the recpiver coil)

016 per degree Cent igrade o r an accuracy of m e p a r t i n bo00 for an uncertainty i n temperature of no more than one degree Centigrade

Trains o f 1 microsecond pulses were r e c i r c u l a t e d a t a clock frequency o f 350 kc (these represent the limit of s table operati on

Unaltered 0045 inch OD tube 0002 inch wall

527 microseconds

Between 05 and 3 microseconds optimum pulse width 15 microseconds

Never less than 13 microseconds

L 5 nricroseconds

167 microseconds

40 db t o 60 db

6 dblOO micmseconds

1Ol to 20l

Not measured presumably the same

Trains o f 1 microsecond input pulses were re- c i r cu la t ed a t a clock frequency of 600 kc

3

delay line t o be delayed 5-27 microseconds compared with the output of the para l le l electrical branch

l The V i l l a r i or inverse magnetostrictlon effect refers t o a change i n magnetization with the presence of an e l a s t i c strain Associated with the

l i n k s the windings of the receiver coil and the delay element When the instantaneous strains propagated from the transmitter transducer arrive In the postion of the delay element surrounded by t h e coil of the receiver the bias f1uXis changed and a voltage is induced i n the co i l An optimum input pulse duration gives r ise to output pulses of as much as 05 v o l t

I receiving transducer (Fig 1) is a biasing magnet t o produce a f lux which

mNT FLUX STRAIN OUTFUT VOLTAGE

Fig 2 - Qual i ta t ive der iva t ion of output pulse shape

The polar i ty of the output pulse is determined by the d i rec t ion of t he bias vector in the delay element The optimum pulse durat ion for maximum output i s not necessarily t h e pulse duration for best resolution because of the difficulty in constIocting tr5nsducer coils which are short i n r e l a t i o n t o the length of the disturbance in the delay element

A qual i ta t ive way to predict the expected output pulse shape is t o consider it a second derivative of the input pulse shape The expected flux pulse strain pulse and voltage output pulse for a squarecurrent pulse in the t rznsmizter coi l are shown qualitatively ir_ Fig 2 Oscillo- scope traces of actual input and output voltage pulses are given i n Fig 3

The analogous c i r c u i t of the transmitt irg transducer can b erived from the conventional analysis of a magnetostrictive transaucery2y under the following assumptions

1 The tubular delay element v ib ra t e s only i n t h e longitudiral mode

2 The transmitting transducer has no biasing flux and a frequenq doubling effect takes place

4

3 me transmitting transducer can be considered t o be com7osed of two elementary transducers each of length l equa l t o ha l f the transmitt ing coil such tha t there i s a node of motion a t t h e i r junction

h Although the transducer element i s contiguous wi th the delay element it is possible to incorporate the load presented by the delay element that is i ts character is t ic impedance Zo i n the bmndaqy condi- t ions Hence for the purposes of analysis an isolated transducer element can be considered

Using the analogy which associates velocity with voltage and force with current the equivalent circuit shown i n Fig 4 then holds A t t he ( e l ec t r i ca l ) input of the c i rcui t EA = Eo Cos 2 W t is the driving voltage and 2 = R + j WL

is the ixpedance The couplhg coefficient is D - Pox --$--- where Yo i s

youngs modulus A i s the magnetostrictive coefficient which is taken t o be proportional to the f lux densi ty N is the number of turns and R is the reluc- t a c e of the magnetic path A t the (mechanical) output Z2 is the pa r t i c l e velocity of the f ree end of the transaucer The expression f o r the mechanical inpeclance conta ins the ckrac te r i s t ic impedance 2 = S Y$ and the phase velocity V - 1 Yo p where S i s the cross-sectional area and P i s the dersity of the delay element

2 N

r3

The c i r cu i t proves t o be s o nonlinear that it i s not prof i table t o attempt t o determine the pulse response The analysis does show the bad mismatch between the e lec t r ica l impedance of the transducer coil and the e lectr ical equivalent of the mechanical impedance of the nickel tubing However t h i s mismatch is not of great importance since the pmer efficiency of the delay l ine sgt-stem is of l i t t l e i n t e r e s t I n fac t so l i t t l e energy is taken from the

Fig 3 - Input and output voltage pulses 2 pseccm

5

following the signal pulse K i l l be received

CONSTRUCTIONAL FORM

A laboratory model of a high-resolution mgnetostrictive delay l ine i s shown i n Fig 5 The delay element i s a three-foot piece of 00115 inch OD nickel tubingof 00025 inch wall thickness in a temper specified by the supplier as full hard It i s threaded through the center holes of the transmitting and receiving transducers A piece of aluminum channel r ig id ly supports the coils Provision i s made t o move the lreceiver mount to adjust the amount of delay The transmitter coil ir th i s Far t icu lar ins tance i s inside the driver chassis which is mounted on t h e right-hand end of the aluminum channel The ends of the tubing are held by metal clamps t o prevent sl ipping and to insure good e l ec t r i ca l grounding

delay element i n detecting the signal t ha t n a n y receivers may be arranged along the tube without a noticeable increase in attenuation of the s ipa l

The disturbance is propagated in both directions -from the transmitter transducer The open ends of the nickel tubing act as almost perfect reflectors and the attenuation in the nickel tubing I s o n l y 6 db per 100 microseconds Udess some means of echo su2pression i s incorporated trains of spurious pulses

1 1 i 1

I i

l l

Fig 4 - Equivalent circuit of a r+wtostrj c- t i v e delay line

6

Fig 6 - A transducer coil

A typical t rvlsducer coi l is shown i n Fig 6 A t o t a l of 250 turns of No h0 wire were wound on a f iber spool which was seated i n two Ferroxcube IV f e r r i t e cups with center holes for the dehy element The en t i r e assembly was encapsulated i n a resin

BiasinG magnetic flux f o r the receiver coi l is supplied by a U-shaped Alnico V magnet affixed t o the holder of the receiver coi l so t ha t t he magnet is moved with the c o i l Echo suppression was achieved h t h i s instance by thin- ly coating t h e enamp of the tube with a st icky wax mixture which w i l l be described

DESIGN CONSIDERATIONS

It was decided t o restrlct the investi jzt ion of delay e lemnts to tubular forms irstead of rods ribbons or wire Rods offer l i t t l e advantage SO far a s r i g id i ty is concerned over tubular elenents of the s a m diameter Since it is reasonable to assume that the f lux penetrat ion a t the operathg frequencies i s very small the output from a rod i s lower than f ron a thin- wall tube of the same dia-neter because of the increased mass loading of the rod Filamentary ribbons and wires were a l s o ini t ia l ly discarded because in order t o avoid j i t ter i n a large continuously adjustable delay l ine f i la- mentary elements would have t o be held under tension Tubing i s qui te r ig id and self-supportinz 2nd c m even be fo lded t ro ~~one- f ~ s i~~ o r coilsd

Tle opinion among sone workers in t h i s f i e l d is t ha t ribbon-sl-ped delay clclents have an inherently better frequency response tnan do tuhes

tcbe of 0125 inch OD is achieved by s lo t t ing the tubing along i ts length thus essentially converting it in to a ribbon Reasoning from t h i s point l2amp t o the conclusion at the reduction of the cross section of the ribbon lessens eddy-current losses and so extends the frequency response It w i l l be

as an hprovement in frequency response a t l e a s t i n the case of a l

however t h a t the poor frequency response of the 0 l25 k c h 0 D tubing inherent a d i s due t o an attenuation band in its frequency response

The frequency response of any tube will exhibit an attenuation band m Width and posit ion of these bands are a function of the radius of the

7

3

S tube and the Poisson r a t i o of t h e tube material Adequate high-frequency response can be obtained without the necessity of slott ing the tubing by choosing a tube of the proper diameter since the high-frequency response

current losses in the transducer In fact the frequency response of a tubular element may be superior in some cases t o t h a t of a ribbon whose width is the sampe as t h e circumference of the tube and which has undergone the same heat-treatment

- l] A- under the best of circumstances is l imited t o about one megacycle by eddy-

1 r

f

The assumption in the theoret ical analysis of the transrnitting transducer that the tube oscil lates only i n the longitudinal mode is not completely valid Actually there exists a coupling between the radial and longitudinal modes since a longi tudinal s t ra in is accompanied by a transverse strain as measured by tke Poisson ratio

It campr be shown that given a tube excited i n axia l symmetry on ly the fundamental frequency of the radial mode can be excited that is

fr =

is the only frequency possible in the tube i s x then the frequencies which mode are

2lTr p I p

pure radial mode If the length o f the can be e x c i t e d i n the pure longitudinal

The actual frequencies F i n which the two coupled osc i l la tors can be excited a re bu i l t up o f combinations of the two partial frequencies according to the formula

1rhere-P is the Poisson r a t io This resti l ts i n two ser ies of frequencies serizs I (using the negative sign) always lower than fr and se r ies I1 always higher lheye are four l imiting cases

1 r- 0 (very thin tube) fr- Q) and F1 = kf (Pure longitudinal vibrationj

2 If x- 0 ( r ing of radius r) f- rb this gives the highest limiting frequency of the series FI FI fr

3 If x- a ( inf in i te ly long tube) the fundamental frequency F- 0 and there are of course no harmonics possible This gives the lowest frequency possible f o r Ser ies 11

8

4 If r ---c a0 with fx = 0 (large diameter tube) the highest frequency of se r ies I1 results

Given thin-wall tubinz the two possible frequency bands (F1 and FII) do n o t overlap and there exists a frequency region -

which is only a function of f andamp in which it is impossible t o excite the tube regardless o f the length of tubing ueed o r the hannonic of the fundamentd longitudinal mode chosen

Curve nan of Fig 7 is a frequency p lo t for a 0125 inch OD 0004 inch w a U nickel tube (unslotted) sharing a strmg a t tenuat ion band beginning at approximately 500 kc Curve b shows the same tube but with a longitudinal s l o t cut i n the tube which effectively converts the tube to a ribbon of width x = ( 2 7 r width of s lo t ) For such a ribbon the attenuation band starts a t the frequency

PI max (ribbon) = fx =

9

radius of the tube and the Poisson ratio These considerations determined the choice of OOamp inch 0D nickel tubing i n the development of a high resolution delay line This choice also obviates the necessity of s lo t t i ng long pieces of nickel tubing

Tile considerations mentioned above a r e valid for delay lines of any length For delays of greater than approximately 300 microseconds however the de lay l ine suf fe rs a severe loss of resolving power aa evidenced by a degeneration o f the shape of the so2ic pulse in t r aveUlng along the tube This degeneration has been related t o an observed dispersion effect -- a variat ion o f velocity of propagatioll with frequency Experimental meassrements on a 00ks-inch OD nickel tube have shown a decrease i n velocity of about 3 between 2 ard 1000 kc T k i s change i n veloci ty i s great enough t o explain the observed pulse degeneration O t h e r such dispersion measurements i n tubes Of various w a l l thicknesses and temper have showr that although the velocity increases with increasing w a l l thickness it does so a t every point s o tha t the shape of the d i spe r s ion curve remains the same but the shape of the dispersion curve i s improved i n tubes of harder temper A one-millisecond experimental delay line using a full hard 0003 inch w a l l 0045 inch OD nickel tube permitted the recirculation of t r a i n s of pulses at a maximum repe t i t ion rate of 300 kc The construction allowed a continuously variable delay of from 5 microsecords to 1000 microseconds The signal-to-mise ratio at 300 kc w a s about 81 at 250 kc it was greater than 10l

Eighteen lots o f OIO45 inch OD tubing (6 different w a l l thickness i n each of three tempers) were tes ted for pulse response to determine the b s t e n c e of an optimum combination of w a l 3 thicknesses and temper f o r a given input pulse The w a l l thicknesses were 00015 0002 0003 0005 and

W c t

----0125 00 TUBING SLOTTED -0125 00 TUBING UNSLOTTED

0045QD TUBING UNSLOTTED (CONSTANT INPUT CURRENT)

I I l

i

l 1

200

FREQUENCY IN KC 300 4 00 5 0 0 600 TOO (I

I Fig 7 - Freqatncy characterist ics of nickel tubing

10

t -------

t INPUT PULSE W I D T H - M M C R O S E C O ~ D S WALL THICKNESS -INCHES WALL THICKNESS- INCHES - DEAD SOFT -

(AVERAGED OVER HARD I MICROSECOND INPUT PULSE

MEDIUM AND MEDIUM TEMPERS 1 _ _ 2 MICROSECOND INPUT PULSE FULL HARD 3 MICROSECOND INPUT PULSE

-- - --_

(AVERAGED OVER WALL THICKNESS )

--

c 3

c 3 0

n

2 t 0-

002 004 006 OOB WALL THICKNESS- INCHES

- I MICROSECOND INPUT PULSE --- 2 MICROSECOND INPUT PULSE -- 3 MICROSECOND INPUT PULSE

W

3 c n

1 2 3 MICROSECONDS IN PUT PULSE WIDTH - DEAD SOFT

--- MEDl UM -- F U L L HARD

(AVERAGED OVER WALL THICKNESS)

Fig 8 - Output pulse characterist ics for various delay elements

0007 inches the tempers ampe specified by the manufacturers as dead sof t mediumn and 1 ful l hard ft

Pulse response data of output pulse xidth pulse amplitude and the ratio of the amplitude of the first ringing pulse t o the amplitude of the desired ifitelligence pulse were taken for 1 2 and 3 microseconds 30 vol t input pulses Typical input and output pulses are shown i n Fig 3

A two-fold stardard was used to deternine the optimum response the Output pulse width closest t o t h e width of the input pulse and the g rea tes t Pulse amplitude obtainable with the least amount of ringing

The pulse-response data i s summarized i n Fig 8 Fig 8a shows output-Pase duration vs inputpulse durat ion averaged over the six samples of

- 11

l

l

J

w a l l thicknesses with temper as a parameter The curves indicate that the dead soft1 tubing i s cot recommended for the best resolut ion and that there i s l i t t l e difference between the output pulse widths for f 9 w d i u m 1 ani full hard tempers When the data from the dead soft tubing is excluded and the values of the llmediumR and full hard tubing averaged Fig 8b shms that the output pulse width i s not a functior of the w a l l thickness Figs 8c and 8d show tha t optimum tubes exis t for the one-microsecond two-microsecond and three-microsecond inputs which are 00025 inch 0003 inch and 0005 inch i n wall thickness respectively i n eitheredium o r fill bard tempesls on the bases of pulse amplitude and ringing

The temperature dependence of delay w a s measured by heating the nickel tube i n 6 steam jacket from room temperature (200 C ) t o 100 C and noting the c halge i n delay tim with temperature is l i n e a r i n this range two points were obtained mak- ing possible an approximation of the var ia t ion of delay with temperature without having t o set up an accurately controlled oven The given specimen of nickel showed an increase in delay of 0016 o r an accuracy of one par t i n 6000 per degree Centigrade of temperature r i s e i n t h e range tested The- ampstance between the transducers was r ig id ly fixed and the tube was f r ee t o s l i p so that the change i n delay was due t o the ctange in veloci ty and not to l inear expansion of t he tube although the percentage variation in delay per degree Centigrade due t o expansion i s small canpared t o that due t o change i n velocity

AssrrmiY5J hat the var ia t ion in ve loc i ty

A 8 can be seen from the pulse response data cited above the design of the transmitting armd receiving transducers i s of great importance in achiev- ing the optimum response of the system f o r a given input pulse Thus t he length of the transmitting transducer including fringing determines the optimum pulse width that can be used This fact can be seen by referr ing t o Fig 8e which shows the pulse amplitude (averaged over all w a l l thicknesses) as a furctior of input-pulse duration with temper as a parameter and using the same trm-smitting transducer The shapes of the three curves are the same peaking a t a two-microsecond input pulse and are only sl ightly displaced for the different tempers I n other words each of the tubes regardless of w a l l thickness or temper gave higher output for a two-nxicrosecond pulse than a ore- microsecond or three-Ficrosecocd pulse

There i s a frequency of mechanical resonarice whose wavelength i n the n i c k e l tube i s twice the length of the t rammit t ing coi l on a sinusoidal basis It i s therefore desirable to match the length of the transmitting transducer t c the required pulse duration

For example i f a two-ricrosecond pulse is to be used the length of the tramducer plus the f r i n g i n g should be approximately

where L = length of transducer cm C = veloci ty of propagation cmsec f - freqwlncy i

12

I

l

0 005 010 0 15 020 025 030 I PEAK INPUT CURRENT AMPERES

Fig 9 - Voltage output VS current input at transducer coils

The duration o f the pulse is considered t o be one half the period of an equivalent sinusoidal vibration thus in this case the equivalent frequency i s 2 9 kc The receiving trarisducer should be as short as possible since the output pulse from the receiver has the duration of the d i s turbaxe in the nickel plus the time f o r the dis tvrbaxe t o t r a e l thrcuch the coil

I n order t o limit the f r ipg ing it i s necessary t o have some s o r t of flux-return path around the coil This may consist of a sleeve of s o f t magnetic material For the best containment of flux as well as for minimization cf eddy-current losses in t he r e t u r n the co i l s are completely enclosed in Eerroxcube IV cups Since there i s no b ias ing f ie ld at the transmitter the R2p betweell t h e f e r r i t e cup and the nickel tube is m d e as small as possible t o decrease the magnetomotive force drop i~ air Tlie gap ai the receiver ImSt be larirc enough tha t the biasing permarent magilet i s not ccjrpletelJ d ~ c r t e b l ~ e~ lie Terrjie r e t u n

The magnetostrictive effect saturates f o r I-fish field s t r e ~ y t h Fig 9 which i s a p l o t of output-pulse amplitude vs input current fcr one-irLcrosecond pulses and f o r a 250 turn transmitting transducer silows that the m a x i m u m output i s obtained for a current pulse of 019 amperes or a magnetomotive force oft approximately 35 ampere-turns (The greatest gain occurs at 675 sunpere- turns It i s t o be noted however that since the output i s small i n ary case the maximum T l i t u d e rathr than greatest efficiency is desirable) This would indicate tkt-a-t b having a large number of turns on the transmitting Coil the current reqdremnts of the driver tube could be minimized Increasing the

~ n m e T of turns however lowers the self-resonant frequency of the coi l thus i Lqhducing undesirable ringing A c o i l winding of 250 turns uhich causes the

bansducer coil to be self-resonant at 1b megaCYdes presents a cornprodse xbetmen the need f m a large number of ampere-turns and a c o i l which resonates at a frequency higher than the limit imposed on the system by eddy-current losses and f o r is reason has been chosen as the opt Coil

ampU There are two essent ia l ly d i f fe ren t methods of a t t a c k i x the problem 9 Of Suppressing the s P ~ o u s pulses a c h arise from reflections a t the ends of jt

13

the tubing The one method depends upon interference effects and the other on the use of a dissipative tenrdnation

If the ends of the tubing are deformd either by crushing or preferably by s l i t t i n g and forming leaves the deformation ca S S the sonic energy t o be divided among several different modes of vibration Statist ical cancellation8 occur among the modes a t the rece iver resu l t ing in a low l eve l of somewhat randon noise If there are l a rge peaks present it i s possible to reduce them by kinking the leaves It can be seen that these cancellations occur a t cer ta in points on ths tube and moving the receiver coi l away from one of these points may mampe it necessary t o retune the echo suppression I

Y d

The second method makes use of a sticky mixture of one p a r t beeswax t o two pa r t s ester gum and two par t s tri-cresyl phosphate (plasticizer) applied ho t t o the ends of the tubing i n a t h i n coat This mixture i s extremely lossy and when applied properly the character is t ic impedance of the nickel tube is not appreciably altered In effect t h i s can be considered analogous t o ter- minating a transmission l i n e in its character is t ic impedance Fig 10 snows the output of the l ine with and without the dissipative termination A reduction i n the echo peaks t o 20 o r 30 db below the signal peak is easily achieved

The requirement of a peak magnetomotive force of 35 ampere-turns at the transmitting transducer using a 2) turn coi l necessi ta ted a current pulse of a t least 1 milliampeles from the driver A single 6AG7 tube connected as shown i n Fig ll was used t o supply this current The tube is normally biased to cutoff the application of a 30 volt posi t ive pulse on the grid produces a large pulse of current i n t he t r ansmi t t i ng coi l

In order t o ge t t he bes t r e so lu t ion and minimize ringing the input capacitance of the circuit associated with the receiving transducer nust be s d l enough t h a t the coil resonates appreciably above the operatin2 frequercr For exampls W t h e de lay l ine i s operated a t a 450 kc repe t i t ion rate using a c o i l of 250 turns having an inductance of approximately 17 mill ihenries and a dis- tributed capacitance of about 8 mmfd and i f the input capacitance of t h e ampli- f i e r is 5 d d t h e c o i l w i l l be resonated at a frequency s l igh t ly below 1 IX Ringing can be controlled t o sons extent by the use of a damping r e s i s t o r across the receiving coil

One receiver amplifier circuit which was used is shown i n Fig 12 ThiE c i r cu i t gave an output of approldmately 125 v o l t s f o r an input of 0 Os vol t s a t the te rmina ls of the mceiver co i l The amplifier was designed specificalPJ t o operate into a reshaping circuit which converts the palses to 01 microsecond pulses for w e with Burroughs pulse control equipment

The tuhirg which forms the delay element mst be supported in such a way t h a t ttle distance between the input and outpu transducers does not vary with mechanical shock This is done t o prevent j i t ter If necessary supports cn be placed between the transducers provided that the surface bearing on the tube is a lmife-edge of same p las t ic such as polystyrene o r cellulose acetate Supports so f o m d w i l l not introduce spurious pulses or appreciably attenuate the s i g d even if a spring-loaded clamp i s used

14

- 1

Fig 10 - Transmission l i n e output with and without dissipative t e r - h a t i o n 22 pseccm

TRANSMITTING TRANSDUCER

r-1

b I- - - d -15 VOLTS +250 VOLTS

Fig 11 - Driver circui t

If a contiruously variable cielay is desirable means must be provided t o nove the rece iv ing co i l s re la t ive to the t ransni t te r t ransducer i n such a trny tat the tubing i s not strained Fig l3 shows one method used i n a pm- totype model contained in a rack-mounting chzssis I n t h i s case a yoke which carr ies the pickup coi l and magnet i s mounted i n a s l o t on the f ron t panel Coarse adjustnents are made br loosening the thumbscrew on the clamp and sl i i - i q t he en t i r e unit Fine adjustments are made by turning the knurled nut tklus moving the yoke with respect to the clamp A pointer mounted on the yoke and a calibrated Ecale a l o x the slot would give a visual indication of t he length of delay without any problem of backlash

+l05 VOLTS

l

RECEIVING

I MEG

Fig 1 2 - Receiver amplifier

APPLICATIONS

Among the possible applications o f the device the following are im= mediately apparent

1 Pulse Delay U n i t

The device shown i n Fig l3 can be used with the proper pulse- shaping c i rcui ts t d rot+de f ixed or variable pulse delays of up t~ 250 microseconds e-itilcr as a portion o f a l a rger system or w i t h a self-contained gto~~r supply as ar independerh piece of l a m r a t o r y equipment

2 Storage U n i t

If the output pulses of a de lay l ine a re used t o open a gate and allow a new clock pu l se t o be pu t i n to the t r a w i t t e r f o r each received pulse information can be regeneratively stored Fig 14 is a block diagram of a c i r c u i t composed of BwToughs Corporation pulse control equipment used for Zorming a t r a i n of pulses and circulat ing it on a delay line A single pulse f r o n the pushbutton pulse train in j ec to r allows a t r a i n or a predetermined number o f 01 microsecond pulses to be injected i r to the mixer a t thAe clock frequency rate A t the output of t he mixer the 01 microsecond pulses are converted t o 09 microsecond pulses a t a L50 kc r epe t i t i on r a t e ad sent into t he d r ive r of the Menor U n i t After traversing the delay l ine the pulses are amplified ad reshaped t o 01 microsecond 30 tTolt pulses

16

3 Circuit Element

17

09~ SEC DELAY r - - - - - - - - D U I - MAGNETOSTRICTIVE MEMORY UNIT

PULSE TRAIN I N J ECTOR I TRANSMITTER - 2 7 5 ~ SEC- RECEIVER I

I I A l 0

FLIP-FLOP I TRANSDUCER

DELAY

109~ SEC I -1 D R I V E R A 1- I

I 5 U SEC L - -v - - - - - 2-1 DU -

4 5 0 K C 0 I C FLIP-FLOP

I 5u SEC I D

Fie 14 - LOOP of pulse control equipment for regenerative storage

Fig 15 - Waveforms at t e s t points in Fig 14 A = 2 pseccm 15 v cm B = 6 pseccm 1 v cm C = 6 yseccm 15 v cm D 2 weccm 15 v cm

18

l

I

Fig 16 - Four-channel pulse distributor

mmr0 For example the f a c t that very l i t t l e of the sonic energy is used i n detecting the signal makes it possi3le t o arrange sevsral receivers along the l i n e without appreciably increasing the attenuation A device having a number of such outputs could be used as a multichannel pluse distributor o r by the addition of gates a serial- h - p m m e l converter s ~ l a r l y the incorporation of several input

makes possible a parallel-to-serial converter A Prototype model of a pulse distributor for a four-channel output was

fo r laboratory testing See Fig 16 It is composed of a

19

Fig l7 = Output of pulse dist r ibutor 10 pseccm

line having a total delay of approximately 85 psec with four receivers The receiver positions with respect t o one another are variable such tha t t he m i n i - m possible distance between adjacent receivers i s one inch or 527 )rsec This spacing could be made smaller by a different mechanical design Fig 17 shows the output of f o u r channels fed to a mixer f o r the purpose of photographing the output pulses of the pulse distributor Ihe variation in pulse amplitudes i s du to the d i f fe rences in ampl i f ica t ion in the four individual amplieuroier channels

4 Variable Frequency Oscillator 1

The use o f the delay l ine i n an embodiment allowing continuously variable 4 delay over a range with a suitable amplifier makes possible a variable frequency 4 osc i l l a to r Such a device shown i n F i g 18 can cover- a range of frequencies -over 35 decades with one control

5 Static Storage Device F

Some receiving c o u s were constructed having two concentric windings If the ou te r co i l i s connected to the amplifier and inner coil connected momentarily across a 15 vol t bat tery f l l f f ic ient res idual magnet izat ion i s imparted to the portion of the delay element under the coil particularly if it i s of nickel of a hard temper t o allow subsequent operation without an external biasing magnet Reversing the ycIes of thz battery incrnentarily reverses the Fhase of the output si p a l

If a mul t ip l ic i ty o f such heads were spaced along the delay element information c m l d be read into the l ine through the bias control windings s to red s t a t i ca l ly by means of the direct ion of the magnetization vector of the biaa fields and read o u t by passing a sonic pulse down the l i ne

It was further found that connecting a high impedance across the terminals of the inner coil did not apFreciably affect the pulse amplitude a t the terminals of the pickup windings but connecting a low impedance across the inner coil sumyessed the pulse almost completely This e f f e c t sug- gests a gate

While the delay line can be used i n various forms f o r ari thmetic operations one example showing binary rnultiplication i s given in Fig 19 The features of the delay line which are u t i l i zed a re (1) Infor- nation can be recirculated conveniently a t pulse repet i t ion ra tes

20

up tcb 600 kc and ( 2 ) output transducers can be placed a t various O i I t s along the delay l ine without distwbing the n o d operation The opera-cion of the multiplier wCl3 be described with reference t o ne 19 which shows e s se r t i a l ly two delay l ines used as pulse dis- tribvtors one recirculat ing delay l ine and one output or product register The schematic has been drawn fo r the multiplication of two four-bit bin- numbers The aim is to point out the approach ex- tensions t o the multiplication of coded decimal numbers and the l ike should be evident

Suppose f o r example the multiplicand is X = I l O O and the mult ipl ier is Y = 1001 The r eg i s t e r s X and Y are assumed f i l l e d before the multiplication i s to take place Note that the X register contains the binary bits i n the reversed order and the Y regis ter contains the bits i n the usual order A set pulse starts the multiplication cycle which w i l l be complete in 2n + 1 pulses The frequency of the clock pulses is assumed t o be 250 kc i n Fig 19 The set pulse does four things It i s put into the pulse distributing line it shifts the first digit of the multiplicand into the recirculating delay l ine it sets FF 1 t o allow the pulses from the X register t o en ter the rec i r - culating delay line and s e t s FF 3 f o r control of the output register The set pulse then travels down i t s pulse dis t r ibut ing l ine and succes- sively shifts each of the X b i t s i n t o the recirculating delay l ine a t pos i t i on 5 through a delay of 2 microseconds and the l ine dr iver After 1 2 microseconds the pulse a t posit ion 3 goes in to the second or lrYn pulse distributing delay l ine and a lso shifts the first b i t i n t h i s case a 1f l l1 which opens the gates from the Y r eg i s t e r i n to co i l s Of the recirculating delay l ine through a suitable driver i n accordance Kith the explanation of the gatell action at each of the output stations On the recirculating delay l ine This pulse also sets FF 1 to enable mxcessive recirculation of pulses on the recirculating delay l ine Sixteen microseconds a f t e r t he s e t pu l se appears each b i t of multiplicand i n t h e farm of the presence or absence of sonic pulses on the recirculating delay l ine i s i n its respective posit ion under each of the four output stations i n this exanple oou reading from l e f t t o r igh t In accordance with the previous explanation of the action a t each of the output statio- of the l ine 00n appears i n this case a t the -4 -31 -2 -1 parts of the output or X Y register After 20 r n i ~ ~ o ~ e c o n d s tine pulse positions on the recirculating delay l i n e are i n the 1001 Position fo r this example and the second b i t of the Y r eg i s t e r if3 shifted into co i l s 1 and SO on f o r the next two successive pulses from the y reg is te r which accumulates the p a r t i a l products under the control Of the FF 3 4 and 5 from the properly tinmecl pulses 6 7 and 80 The Eates a t the ou tput of the delay lines avoid ampy spurious pulses from

if desired The reset pulse a t s l igh t ly g rea te r than 2Mt + 1 microseconds after the set pulse appears where T i s the basic time between pulse posit ions or 4 microseconds i n the example and M i s the number Of bits i n X o r Y resets the m u l t i p l i e r for the ncxb multiplication The x and y r eg i s t e r s cm be f i l l ed while the device i s resett ing The next se t pulse starts anoher multiplication and SO on

the output register Pulse 8 can be used as a round-off p3ise

21 t

I

i j lL--t-++l AMPLIFIER

Fig 18 - Variable frequency oscillator S E T 0 DISTRIBUTOR

DELAY LINE

__3 4 p sec SENSE 4~ 4p sec

MULTIFLICANC

FFI

I r L I l

REAC IN

RECIRCULATING DELAY

1

2 ~ s e c 49 sec 49 sec 49 sec

REGISTER CONTENTS I

r

B + I

5 sec

DISTRIBUTOR DELAY LINE

5 0 l I 0 0

0 0 0 0 0 0

0 0 1 I 46 REFERRED TO

XY REGISTER Y REQISTER DIGITS

Fig 19 - Multiplier using magnetostrictive delay line

22

DISCUSSION

Where relatively poor resolution can be tolerated the r ~ ~ e t o s t ~ ~ c ~ ~ delay line described i n t h i s paper offers many advantages over o t E r t j p e s cf delay lines capable of the same function The magnetostrictive delay E n s S inexpensive and the necessary associated equipment is quite S- e Table 11

a magnetostrictive delay line with a mercury delay l ine t 7 )

Comparison of Magnetostrictive Delay Line and Kercury Delay Line - ~ _ _ _

Characteristic I

Resolution

RF ca r r i e r needed

Mechanical impedance-match between transducer element and delay element

Temperature s t ab i l i t y pe r degree centigrade

Delay per l i n e a r inch

Ease of construction

RuggedRess

Compactness

Attenuation

-~ ~~~~

Continuously adjustable delay

Mercury Line

No

Up t o 4 pulses per microsecond

Yes

Good

1 p a r t i n 3000

175 microseconds

Difficult requires ground and lapped reflectors accurately positioned

Subject t o leakage and contamination

Good many channels i n one tank

60 db

Mzgnetostrictivs L P s

Yes

NO

527 raicrcsecon~s

23

- - i

Delorenzo A Yngnetostrictive Delay Line Unpublished masters thesis Moore School of Elec3rical Zwineering University of Pennsylvania 1950

Giebe E and Blechschmidt E merirnentelle und Theoretische Unter-

nPlagnetostrictionlf Bulletin of International Nickel Co Fig 7 (1950) - - - kenberg tlSupersonic delay lines Radiation Laboratory Xeport NO 932 - -

3

4

5 6

7 Tompkins Wakelin and St i f f le r High Speed Communicating New York McGraw-IIill Book Compaqy Inc p 341 1950

TRANSDUCER RECEIVING

TRANSMITTING TRANSDUCER ampBIASING MAGNET

MEANS OF ECHO ELEMENT SUPPRESSION

GROUND

Fig l - Schematic representation of a typi- c a l magnetostriction delay l ine

were designed t o work with t h i s tubing and a sui table method of echo suppression was devised The resulting magnetostriction-sonic delay line had three main features in addition t o the charac te r i s t ics mentioned above

1 It operated with pulses of the order of one microsecond duration 2 The signal-to-noise ratio was a t l e a s t 10l 3 Pulse information was stored at a clock frequency as great as

6 9 kc -

Depending upon the frequency response t h a t is required i n a given in- dance two possible forms of the delay element have been evolved I n ap- p l i ca t ions fo r which the resolution requirements are not stringent it i s advantageous t o use a nickel tube of approximately 0125 inch OD because of t h e r i g i d i t y and the consequent simplicity of construction of the whole dedce If it i s desirable to obtain the maxFrmLm possible resolution con- sistent wlth the rserious l imitations that eddy-current losses impose upon the frequency response it is necessary t o decrease the diameter of the tubing

Q

It will be shown that tubing of OmObs inch OD gives a frequency response of at l e a s t up t o t h e lhit imposed by the eddy-current losses a lso that further decrease i n diameter or the subst i tut ion of filamentary ribbon or wire-shaped elements i s not profitable since the improvement i n frequency response is balanced by extreme f r a g i l i t y and- d i f f i cu l ty i n construction The character is t ics of delay l inea having the two possible forms are compared Fn Table I

lEDeuroE OF OPERATION

The operation of the delay line depe-ds upon three basic phenomna (see Fig 1) the insertion of pulses in an e l a s t i c m e d i u m by means of the Joule magnetostrictive effect the propagation o f sonic energy i n the e las t ic medium and the reception of the pulses by means of the V i l l a r i magnetostric- t ive effect

The Joule effect refers ta a change of physical dimensions with the application of magnetic flux A material which expands with the application of flux i s sa id t o have a positive magnetostrictive coefficient a material

2

TABU I







Iksertion loss




ulse Circulation

Delay Element


527 microseconds



10 microseconds

28 microseconds

40 db t o 60 db






527 microseconds



L 5 nricroseconds

167 microseconds

40 db t o 60 db

6 dblOO micmseconds

1Ol to 20l



3












4






2 N

r3



5


CONSTRUCTIONAL FORM




1 1 i 1

I i

l l


6











7

3




1 r

f



fr =


2lTr p I p







8






9




W c t



I I l

i

l 1

200



10

t -------




-- - --_


--

c 3

c 3 0

n

2 t 0-



W

3 c n









- 11

l

l

J








12

I

l









13



Y d






14

- 1



r-1




+l05 VOLTS

l

RECEIVING

I MEG


APPLICATIONS




2 Storage U n i t


16

3 Circuit Element

17



I I A l 0


DELAY

109~ SEC I -1 D R I V E R A 1- I

I 5 U SEC L - -v - - - - - 2-1 DU -


I 5u SEC I D



18

l

I





19










20





21 t

I



DELAY LINE


MULTIFLICANC

FFI

I r L I l

REAC IN

RECIRCULATING DELAY

1


REGISTER CONTENTS I

r

B + I

5 sec


5 0 l I 0 0

0 0 0 0 0 0




22

DISCUSSION




Characteristic I

Resolution






RuggedRess

Compactness

Attenuation

-~ ~~~~


Mercury Line

No


Yes

Good

1 p a r t i n 3000

175 microseconds




60 db


Yes

NO

527 raicrcsecon~s

23

- - i




3

4

5 6


TABU I







Iksertion loss




ulse Circulation

Delay Element


527 microseconds



10 microseconds

28 microseconds

40 db t o 60 db






527 microseconds



L 5 nricroseconds

167 microseconds

40 db t o 60 db

6 dblOO micmseconds

1Ol to 20l



3












4






2 N

r3



5


CONSTRUCTIONAL FORM




1 1 i 1

I i

l l


6











7

3




1 r

f



fr =


2lTr p I p







8






9




W c t



I I l

i

l 1

200



10

t -------




-- - --_


--

c 3

c 3 0

n

2 t 0-



W

3 c n









- 11

l

l

J








12

I

l









13



Y d






14

- 1



r-1




+l05 VOLTS

l

RECEIVING

I MEG


APPLICATIONS




2 Storage U n i t


16

3 Circuit Element

17



I I A l 0


DELAY

109~ SEC I -1 D R I V E R A 1- I

I 5 U SEC L - -v - - - - - 2-1 DU -


I 5u SEC I D



18

l

I





19










20





21 t

I



DELAY LINE


MULTIFLICANC

FFI

I r L I l

REAC IN

RECIRCULATING DELAY

1


REGISTER CONTENTS I

r

B + I

5 sec


5 0 l I 0 0

0 0 0 0 0 0




22

DISCUSSION




Characteristic I

Resolution






RuggedRess

Compactness

Attenuation

-~ ~~~~


Mercury Line

No


Yes

Good

1 p a r t i n 3000

175 microseconds




60 db


Yes

NO

527 raicrcsecon~s

23

- - i




3

4

5 6













4






2 N

r3



5


CONSTRUCTIONAL FORM




1 1 i 1

I i

l l


6











7

3




1 r

f



fr =


2lTr p I p







8






9




W c t



I I l

i

l 1

200



10

t -------




-- - --_


--

c 3

c 3 0

n

2 t 0-



W

3 c n









- 11

l

l

J








12

I

l









13



Y d






14

- 1



r-1




+l05 VOLTS

l

RECEIVING

I MEG


APPLICATIONS




2 Storage U n i t


16

3 Circuit Element

17



I I A l 0


DELAY

109~ SEC I -1 D R I V E R A 1- I

I 5 U SEC L - -v - - - - - 2-1 DU -


I 5u SEC I D



18

l

I





19










20





21 t

I



DELAY LINE


MULTIFLICANC

FFI

I r L I l

REAC IN

RECIRCULATING DELAY

1


REGISTER CONTENTS I

r

B + I

5 sec


5 0 l I 0 0

0 0 0 0 0 0




22

DISCUSSION




Characteristic I

Resolution






RuggedRess

Compactness

Attenuation

-~ ~~~~


Mercury Line

No


Yes

Good

1 p a r t i n 3000

175 microseconds




60 db


Yes

NO

527 raicrcsecon~s

23

- - i




3

4

5 6







2 N

r3



5


CONSTRUCTIONAL FORM




1 1 i 1

I i

l l


6











7

3




1 r

f



fr =


2lTr p I p







8






9




W c t



I I l

i

l 1

200



10

t -------




-- - --_


--

c 3

c 3 0

n

2 t 0-



W

3 c n









- 11

l

l

J








12

I

l









13



Y d






14

- 1



r-1




+l05 VOLTS

l

RECEIVING

I MEG


APPLICATIONS




2 Storage U n i t


16

3 Circuit Element

17



I I A l 0


DELAY

109~ SEC I -1 D R I V E R A 1- I

I 5 U SEC L - -v - - - - - 2-1 DU -


I 5u SEC I D



18

l

I





19










20





21 t

I



DELAY LINE


MULTIFLICANC

FFI

I r L I l

REAC IN

RECIRCULATING DELAY

1


REGISTER CONTENTS I

r

B + I

5 sec


5 0 l I 0 0

0 0 0 0 0 0




22

DISCUSSION




Characteristic I

Resolution






RuggedRess

Compactness

Attenuation

-~ ~~~~


Mercury Line

No


Yes

Good

1 p a r t i n 3000

175 microseconds




60 db


Yes

NO

527 raicrcsecon~s

23

- - i




3

4

5 6



CONSTRUCTIONAL FORM




1 1 i 1

I i

l l


6











7

3




1 r

f



fr =


2lTr p I p







8






9




W c t



I I l

i

l 1

200



10

t -------




-- - --_


--

c 3

c 3 0

n

2 t 0-



W

3 c n









- 11

l

l

J








12

I

l









13



Y d






14

- 1



r-1




+l05 VOLTS

l

RECEIVING

I MEG


APPLICATIONS




2 Storage U n i t


16

3 Circuit Element

17



I I A l 0


DELAY

109~ SEC I -1 D R I V E R A 1- I

I 5 U SEC L - -v - - - - - 2-1 DU -


I 5u SEC I D



18

l

I





19










20





21 t

I



DELAY LINE


MULTIFLICANC

FFI

I r L I l

REAC IN

RECIRCULATING DELAY

1


REGISTER CONTENTS I

r

B + I

5 sec


5 0 l I 0 0

0 0 0 0 0 0




22

DISCUSSION




Characteristic I

Resolution






RuggedRess

Compactness

Attenuation

-~ ~~~~


Mercury Line

No


Yes

Good

1 p a r t i n 3000

175 microseconds




60 db


Yes

NO

527 raicrcsecon~s

23

- - i




3

4

5 6












7

3




1 r

f



fr =


2lTr p I p







8






9




W c t



I I l

i

l 1

200



10

t -------




-- - --_


--

c 3

c 3 0

n

2 t 0-



W

3 c n









- 11

l

l

J








12

I

l









13



Y d






14

- 1



r-1




+l05 VOLTS

l

RECEIVING

I MEG


APPLICATIONS




2 Storage U n i t


16

3 Circuit Element

17



I I A l 0


DELAY

109~ SEC I -1 D R I V E R A 1- I

I 5 U SEC L - -v - - - - - 2-1 DU -


I 5u SEC I D



18

l

I





19










20





21 t

I



DELAY LINE


MULTIFLICANC

FFI

I r L I l

REAC IN

RECIRCULATING DELAY

1


REGISTER CONTENTS I

r

B + I

5 sec


5 0 l I 0 0

0 0 0 0 0 0




22

DISCUSSION




Characteristic I

Resolution






RuggedRess

Compactness

Attenuation

-~ ~~~~


Mercury Line

No


Yes

Good

1 p a r t i n 3000

175 microseconds




60 db


Yes

NO

527 raicrcsecon~s

23

- - i




3

4

5 6


3




1 r

f



fr =


2lTr p I p







8






9




W c t



I I l

i

l 1

200



10

t -------




-- - --_


--

c 3

c 3 0

n

2 t 0-



W

3 c n









- 11

l

l

J








12

I

l









13



Y d






14

- 1



r-1




+l05 VOLTS

l

RECEIVING

I MEG


APPLICATIONS




2 Storage U n i t


16

3 Circuit Element

17



I I A l 0


DELAY

109~ SEC I -1 D R I V E R A 1- I

I 5 U SEC L - -v - - - - - 2-1 DU -


I 5u SEC I D



18

l

I





19










20





21 t

I



DELAY LINE


MULTIFLICANC

FFI

I r L I l

REAC IN

RECIRCULATING DELAY

1


REGISTER CONTENTS I

r

B + I

5 sec


5 0 l I 0 0

0 0 0 0 0 0




22

DISCUSSION




Characteristic I

Resolution






RuggedRess

Compactness

Attenuation

-~ ~~~~


Mercury Line

No


Yes

Good

1 p a r t i n 3000

175 microseconds




60 db


Yes

NO

527 raicrcsecon~s

23

- - i




3

4

5 6







9




W c t



I I l

i

l 1

200



10

t -------




-- - --_


--

c 3

c 3 0

n

2 t 0-



W

3 c n









- 11

l

l

J








12

I

l









13



Y d






14

- 1



r-1




+l05 VOLTS

l

RECEIVING

I MEG


APPLICATIONS




2 Storage U n i t


16

3 Circuit Element

17



I I A l 0


DELAY

109~ SEC I -1 D R I V E R A 1- I

I 5 U SEC L - -v - - - - - 2-1 DU -


I 5u SEC I D



18

l

I





19










20





21 t

I



DELAY LINE


MULTIFLICANC

FFI

I r L I l

REAC IN

RECIRCULATING DELAY

1


REGISTER CONTENTS I

r

B + I

5 sec


5 0 l I 0 0

0 0 0 0 0 0




22

DISCUSSION




Characteristic I

Resolution






RuggedRess

Compactness

Attenuation

-~ ~~~~


Mercury Line

No


Yes

Good

1 p a r t i n 3000

175 microseconds




60 db


Yes

NO

527 raicrcsecon~s

23

- - i




3

4

5 6





W c t



I I l

i

l 1

200



10

t -------




-- - --_


--

c 3

c 3 0

n

2 t 0-



W

3 c n









- 11

l

l

J








12

I

l









13



Y d






14

- 1



r-1




+l05 VOLTS

l

RECEIVING

I MEG


APPLICATIONS




2 Storage U n i t


16

3 Circuit Element

17



I I A l 0


DELAY

109~ SEC I -1 D R I V E R A 1- I

I 5 U SEC L - -v - - - - - 2-1 DU -


I 5u SEC I D



18

l

I





19










20





21 t

I



DELAY LINE


MULTIFLICANC

FFI

I r L I l

REAC IN

RECIRCULATING DELAY

1


REGISTER CONTENTS I

r

B + I

5 sec


5 0 l I 0 0

0 0 0 0 0 0




22

DISCUSSION




Characteristic I

Resolution






RuggedRess

Compactness

Attenuation

-~ ~~~~


Mercury Line

No


Yes

Good

1 p a r t i n 3000

175 microseconds




60 db


Yes

NO

527 raicrcsecon~s

23

- - i




3

4

5 6


t -------




-- - --_


--

c 3

c 3 0

n

2 t 0-



W

3 c n









- 11

l

l

J








12

I

l









13



Y d






14

- 1



r-1




+l05 VOLTS

l

RECEIVING

I MEG


APPLICATIONS




2 Storage U n i t


16

3 Circuit Element

17



I I A l 0


DELAY

109~ SEC I -1 D R I V E R A 1- I

I 5 U SEC L - -v - - - - - 2-1 DU -


I 5u SEC I D



18

l

I





19










20





21 t

I



DELAY LINE


MULTIFLICANC

FFI

I r L I l

REAC IN

RECIRCULATING DELAY

1


REGISTER CONTENTS I

r

B + I

5 sec


5 0 l I 0 0

0 0 0 0 0 0




22

DISCUSSION




Characteristic I

Resolution






RuggedRess

Compactness

Attenuation

-~ ~~~~


Mercury Line

No


Yes

Good

1 p a r t i n 3000

175 microseconds




60 db


Yes

NO

527 raicrcsecon~s

23

- - i




3

4

5 6


J








12

I

l









13



Y d






14

- 1



r-1




+l05 VOLTS

l

RECEIVING

I MEG


APPLICATIONS




2 Storage U n i t


16

3 Circuit Element

17



I I A l 0


DELAY

109~ SEC I -1 D R I V E R A 1- I

I 5 U SEC L - -v - - - - - 2-1 DU -


I 5u SEC I D



18

l

I





19










20





21 t

I



DELAY LINE


MULTIFLICANC

FFI

I r L I l

REAC IN

RECIRCULATING DELAY

1


REGISTER CONTENTS I

r

B + I

5 sec


5 0 l I 0 0

0 0 0 0 0 0




22

DISCUSSION




Characteristic I

Resolution






RuggedRess

Compactness

Attenuation

-~ ~~~~


Mercury Line

No


Yes

Good

1 p a r t i n 3000

175 microseconds




60 db


Yes

NO

527 raicrcsecon~s

23

- - i




3

4

5 6


I

l









13



Y d






14

- 1



r-1




+l05 VOLTS

l

RECEIVING

I MEG


APPLICATIONS




2 Storage U n i t


16

3 Circuit Element

17



I I A l 0


DELAY

109~ SEC I -1 D R I V E R A 1- I

I 5 U SEC L - -v - - - - - 2-1 DU -


I 5u SEC I D



18

l

I





19










20





21 t

I



DELAY LINE


MULTIFLICANC

FFI

I r L I l

REAC IN

RECIRCULATING DELAY

1


REGISTER CONTENTS I

r

B + I

5 sec


5 0 l I 0 0

0 0 0 0 0 0




22

DISCUSSION




Characteristic I

Resolution






RuggedRess

Compactness

Attenuation

-~ ~~~~


Mercury Line

No


Yes

Good

1 p a r t i n 3000

175 microseconds




60 db


Yes

NO

527 raicrcsecon~s

23

- - i




3

4

5 6




Y d






14

- 1



r-1




+l05 VOLTS

l

RECEIVING

I MEG


APPLICATIONS




2 Storage U n i t


16

3 Circuit Element

17



I I A l 0


DELAY

109~ SEC I -1 D R I V E R A 1- I

I 5 U SEC L - -v - - - - - 2-1 DU -


I 5u SEC I D



18

l

I





19










20





21 t

I



DELAY LINE


MULTIFLICANC

FFI

I r L I l

REAC IN

RECIRCULATING DELAY

1


REGISTER CONTENTS I

r

B + I

5 sec


5 0 l I 0 0

0 0 0 0 0 0




22

DISCUSSION




Characteristic I

Resolution






RuggedRess

Compactness

Attenuation

-~ ~~~~


Mercury Line

No


Yes

Good

1 p a r t i n 3000

175 microseconds




60 db


Yes

NO

527 raicrcsecon~s

23

- - i




3

4

5 6


- 1



r-1




+l05 VOLTS

l

RECEIVING

I MEG


APPLICATIONS




2 Storage U n i t


16

3 Circuit Element

17



I I A l 0


DELAY

109~ SEC I -1 D R I V E R A 1- I

I 5 U SEC L - -v - - - - - 2-1 DU -


I 5u SEC I D



18

l

I





19










20





21 t

I



DELAY LINE


MULTIFLICANC

FFI

I r L I l

REAC IN

RECIRCULATING DELAY

1


REGISTER CONTENTS I

r

B + I

5 sec


5 0 l I 0 0

0 0 0 0 0 0




22

DISCUSSION




Characteristic I

Resolution






RuggedRess

Compactness

Attenuation

-~ ~~~~


Mercury Line

No


Yes

Good

1 p a r t i n 3000

175 microseconds




60 db


Yes

NO

527 raicrcsecon~s

23

- - i




3

4

5 6



+l05 VOLTS

l

RECEIVING

I MEG


APPLICATIONS




2 Storage U n i t


16

3 Circuit Element

17



I I A l 0


DELAY

109~ SEC I -1 D R I V E R A 1- I

I 5 U SEC L - -v - - - - - 2-1 DU -


I 5u SEC I D



18

l

I





19










20





21 t

I



DELAY LINE


MULTIFLICANC

FFI

I r L I l

REAC IN

RECIRCULATING DELAY

1


REGISTER CONTENTS I

r

B + I

5 sec


5 0 l I 0 0

0 0 0 0 0 0




22

DISCUSSION




Characteristic I

Resolution






RuggedRess

Compactness

Attenuation

-~ ~~~~


Mercury Line

No


Yes

Good

1 p a r t i n 3000

175 microseconds




60 db


Yes

NO

527 raicrcsecon~s

23

- - i




3

4

5 6


3 Circuit Element

17



I I A l 0


DELAY

109~ SEC I -1 D R I V E R A 1- I

I 5 U SEC L - -v - - - - - 2-1 DU -


I 5u SEC I D



18

l

I





19










20





21 t

I



DELAY LINE


MULTIFLICANC

FFI

I r L I l

REAC IN

RECIRCULATING DELAY

1


REGISTER CONTENTS I

r

B + I

5 sec


5 0 l I 0 0

0 0 0 0 0 0




22

DISCUSSION




Characteristic I

Resolution






RuggedRess

Compactness

Attenuation

-~ ~~~~


Mercury Line

No


Yes

Good

1 p a r t i n 3000

175 microseconds




60 db


Yes

NO

527 raicrcsecon~s

23

- - i




3

4

5 6




I I A l 0


DELAY

109~ SEC I -1 D R I V E R A 1- I

I 5 U SEC L - -v - - - - - 2-1 DU -


I 5u SEC I D



18

l

I





19










20





21 t

I



DELAY LINE


MULTIFLICANC

FFI

I r L I l

REAC IN

RECIRCULATING DELAY

1


REGISTER CONTENTS I

r

B + I

5 sec


5 0 l I 0 0

0 0 0 0 0 0




22

DISCUSSION




Characteristic I

Resolution






RuggedRess

Compactness

Attenuation

-~ ~~~~


Mercury Line

No


Yes

Good

1 p a r t i n 3000

175 microseconds




60 db


Yes

NO

527 raicrcsecon~s

23

- - i




3

4

5 6


I





19










20





21 t

I



DELAY LINE


MULTIFLICANC

FFI

I r L I l

REAC IN

RECIRCULATING DELAY

1


REGISTER CONTENTS I

r

B + I

5 sec


5 0 l I 0 0

0 0 0 0 0 0




22

DISCUSSION




Characteristic I

Resolution






RuggedRess

Compactness

Attenuation

-~ ~~~~


Mercury Line

No


Yes

Good

1 p a r t i n 3000

175 microseconds




60 db


Yes

NO

527 raicrcsecon~s

23

- - i




3

4

5 6











20





21 t

I



DELAY LINE


MULTIFLICANC

FFI

I r L I l

REAC IN

RECIRCULATING DELAY

1


REGISTER CONTENTS I

r

B + I

5 sec


5 0 l I 0 0

0 0 0 0 0 0




22

DISCUSSION




Characteristic I

Resolution






RuggedRess

Compactness

Attenuation

-~ ~~~~


Mercury Line

No


Yes

Good

1 p a r t i n 3000

175 microseconds




60 db


Yes

NO

527 raicrcsecon~s

23

- - i




3

4

5 6






21 t

I



DELAY LINE


MULTIFLICANC

FFI

I r L I l

REAC IN

RECIRCULATING DELAY

1


REGISTER CONTENTS I

r

B + I

5 sec


5 0 l I 0 0

0 0 0 0 0 0




22

DISCUSSION




Characteristic I

Resolution






RuggedRess

Compactness

Attenuation

-~ ~~~~


Mercury Line

No


Yes

Good

1 p a r t i n 3000

175 microseconds




60 db


Yes

NO

527 raicrcsecon~s

23

- - i




3

4

5 6


I



DELAY LINE


MULTIFLICANC

FFI

I r L I l

REAC IN

RECIRCULATING DELAY

1


REGISTER CONTENTS I

r

B + I

5 sec


5 0 l I 0 0

0 0 0 0 0 0




22

DISCUSSION




Characteristic I

Resolution






RuggedRess

Compactness

Attenuation

-~ ~~~~


Mercury Line

No


Yes

Good

1 p a r t i n 3000

175 microseconds




60 db


Yes

NO

527 raicrcsecon~s

23

- - i




3

4

5 6


DISCUSSION




Characteristic I

Resolution






RuggedRess

Compactness

Attenuation

-~ ~~~~


Mercury Line

No


Yes

Good

1 p a r t i n 3000

175 microseconds




60 db


Yes

NO

527 raicrcsecon~s

23

- - i




3

4

5 6





3

4

5 6


Documents

A High-Performance Magnetostriction-Sonic Delay Line