UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

A sampling-type function generator and four-quadrant analog multiplier Hildebrand, Bernard Percy 1956

You don't seem to have a PDF reader installed, try download the pdf

Item Metadata

Download

Media
[if-you-see-this-DO-NOT-CLICK]
UBC_1956_A7 H3 S2.pdf [ 1.93MB ]
Metadata
JSON: 1.0105061.json
JSON-LD: 1.0105061+ld.json
RDF/XML (Pretty): 1.0105061.xml
RDF/JSON: 1.0105061+rdf.json
Turtle: 1.0105061+rdf-turtle.txt
N-Triples: 1.0105061+rdf-ntriples.txt
Original Record: 1.0105061 +original-record.json
Full Text
1.0105061.txt
Citation
1.0105061.ris

Full Text

A SAMPLING-TYPE FUNCTION GENERATOR AND FOUR-QUADRANT ANALOG MULTIPLIER  BERNARD PERCY HILDEBRAND B.A.Sc. U n i v e r s i t y o f B r i t i s h Columbia, 1954  A t h e s i s submitted i n p a r t i a l f u l f i l m e n t of t h e r e q u i r e m e n t s f o r t h e degree o f MASTER OF APPLIED SCIENCE i n t h e Department of E l e c t r i c a l Engineering We a c c e p t t h i s t h e s i s as c o n f o r m i n g t o t h e s t a n d a r d r e q u i r e d from c a n d i d a t e s f o r t h e degree o f MASTER OP APPLIED SCIENCE  Members o f t h e Department o f E l e c t r i c a l Engineering THE UNIVERSITY OF BRITISH COLUMBIA A p r i l , 1956.  ABSTRACT T h i s t h e s i s d e s c r i b e s t h e design. s.nd development o f a sampling-type f u n c t i o n g e n e r a t o r analog m u l t i p l i e r .  and a f o u r - q u a d r a n t  The p r o j e c t i s d i v i d e d i n t o two p a r t s ,  the g e n e r a l arrangement and c i r c u i t r y o f t h e f u n c t i o n generator  and m u l t i p l i e r , and t h e t i m i n g c i r c u i t s w h i c h  a c t u a t e them.  T h i s t h e s i s i s concerned w i t h t h e g e n e r a l  circuitry. The f u n c t i o n s t o be g e n e r a t e d a r e photographed on 35 mm. f i l m and mounted i n s t a n d a r d frames w h i c h a r e t h e n fastened t o the r i m of a r o t a t i n g disk*  An o p t i c a l system  i s used t o s c a n t h e f u n c t i o n s i n a t i m e - s e q u e n t i a l manner. A t i m i n g system s e l e c t s t h e r e q u i r e d a b s c i s s a and a c t u a t e s a c o m b i n a t i o n o f e l e c t r o n i c g a t e s and c l a m p i n g c i r c u i t s w h i c h s t o r e s t h e v o l t a g e , E^, r e p r e s e n t i n g t h e o r d i n a t e , and  the v o l t a g e , E^, r e p r e s e n t i n g t h e maximum o f t h e f u n c t i o n .  These two s t o r e d v o l t a g e s , E^ and E^, a r e a p p l i e d t o s e p a r a t e sweep c i r c u i t s w h i c h produce sweep o u t p u t s o f E ^ C t ) and Ej^T(t) r e s p e c t i v e l y .  A system o f comparator c i r c u i t s and  g a t e s samples t h e E ^ N ( t ) a t t h e i n s t a n t a r e f e r e n c e E, e q u a l s t h e sweep EgjET(t).  voltage,  S i n c e t h e sweeps, N ( t ) a r e  i d e n t i c a l , t h e v a l u e o f EJST(t) a t t h e i n s t a n t o f s a m p l i n g i s EE. T h i s sequence o f o p e r a t i o n s o c c u r s f o r each f u n c t i o n as i t i s scanned.  Each s u c c e s s i v e m u l t i p l i c a t i o n i s s t o r e d  i n i t s own s t o r a g e u n i t . A l l t h e c i r c u i t s a r e d e s i g n e d t o be s e l f - c a l i b r a t i n g t o m i n i m i z e e r r o r due t o d r i f t .  ii  TABLE OP CONTENTS  TaDLe 03? COIl'tjeil'tjS  o o o o o o o o o o o o o o o . o o o o o o o o o o o o o o o o o  TableS  DO o o o • o o o o o o o o o o o o o o o o o o o o o o  o o o o o o o v o t o  LiS"b 01* IllUStr&tXOnS ACkH0Wl6Cig@II16irt  I II III  Principle  o o o o o o o o o o o o o o o o o o o o o o o o o o o o o  IV V  o o o o o o  1  o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o  of Operation  ,  0  6 o o « o o » o o o o o o o o »  3  o o o o o o o o o o o o . o o o o o o o o .  12  o o o o  0  (1)  Scanning U n i t  (2)  Photo-tube A m p l i f i e r  (3)  H o l d i n g System o f Channels 1 & 3 »»«° °»»° < > 15  (4)  H o l d i n g System o f Channel 2 IllVGrij @X*S  (6 ) Gr8L"fc©S (Y)  12  » o o o o « o o o o o o o o o o » o o » » o o o o o o o  eoooo  O O  O O  SW66p CirC"U.X*tS  14  o . a o o o o o o o o . o o o o o o o o a  O O  O A O O  o o o o o o o o o o o o o o  0 0 0 0 0 0 0 0 0 0 0 0 4 0 0 0 0  16 20  oo o o o o o o  21  o o o o * » 0 » o © o o o o o o o o o o d * o o o * o o  24  o o o o o o o o o o o o o o o o o o  ( 8 ) 0 QTIl J) SIX* St"t? OX*  V  X i i  D e t a i l e d C i r c u i t Design  C5)  17  o o o o e  o o o o o o o o o o o o o o o o o o o o o o o o o o o o o  IntrOdUCtXOn  Xi  oo oo o o o o o o  o o o o o o o o o o o o o  o o o o o o o  oooe  oo o o  ooo  2*7  Accuracy Test o f M u l t i p l i e r  o . o o o o o o o o o o o o o o o o  3©  OOriClXlSXOIl  oooo oo oo oo oo o o o o o o  34  A^)JP^HCLl3C  o o o o o o o  oo  oo oo  oo oo  o o o o o o o o o o o o o o o o o o o o  Sl'bllO^I^Q.piiy  o o o o o o o *  oooo  o o o o o o  ooo/>  35"™3^  oo o oo o o o o o o o o o o o o o o o o o o o o  3*7  iii  TABLES  000000000 o o o o o o o o o 00 000a 000000 o o o o o o o o o 000 *oooooe»a  3?Q,"fol@ «L O O O O O O O O O Q O O O O O O  lELbl© 2  00  00 00 00 00 o o o o  33  M S T OP ILLUSTRATIONS Figure  Page  1  Symbols o f computer u n i t s ..„......»....  2  2  C a l i b r a t i o n and f u n c t i o n frames .......»  4  3  F u n c t i o n g e n e r a t o r assembly  6  4  Four quadrant m u l t i p l i e r . . . . . . . . . . . . . . . 9  5  Function storage  6  Rotating function disk  7  Scanning u n i t assembly ......  13  8  Photo—tube a m p l i f i e r  14  9  H o l d i n g system o f channels 1 and 3  o o o o o ©  •...........  . o o o o o o o o o o o o . o o .  11  o o o o . . o . . . . « . o . o .  12  o o o . . . . . . . . . . . . . . . .  15  10  V o l t a g e s t o r a g e and h o l d i n g c i r c u i t ..•. 17  11  Holding c i r c u i t o f channel 2  12  I n v e r t e r o f channel 1  o o . . . . . . . . . . . . . . . .  20  13  Inverter o f channel 2  . o ^ o . . . . . . . . . . . . . .  21  14  Diode gate  o o . o o o . . o e o o o o o o o o « o o . . . . o . o o  22  15  T e s t setup f o r t h e diode gate ..........  23  16  Sweep c i r c u i t o f c h a n n e l 1  ......... •  25  17  Sweep c i r c u i t o f c h a n n e l 2 •...........•  26  18  C i r c u i t diagram o f m u l t i a r comparator  28  19  C i r c u i t t o match t i m e c o n s t a n t s ........  30  20  Test setup f o r t h e m u l t i p l i e r .........«  31  . . . . . . . . .  s  o •  18  V  ACKNOWLEDGEMENT  The a u t h o r w i s h e s t o e x p r e s s h i s a p p r e c i a t i o n f o r t h e a s s i s t a n c e r e c e i v e d f r o m Dr. E . V . Bonn, D r . A.D. Moore and Dr. P. Noakes of t h e Department o f E l e c t r i c a l E n g i n e e r i n g , The U n i v e r s i t y o f B r i t i s h The  Columbia.  author i s i n d e b t e d t o the Defence R e s e a r c h  Board,  Department o f N a t i o n a l Defence. Canada., f o r s p o n s o r i n g t h e r e s e a r c h p r o j e c t under Grant Number DRB C-9931-02(550-GC) The a u t h o r ' s p o s t - g r a d u a t e s t u d i e s were made p o s s i b l e t h r o u g h t h e N a t i o n a l Research C o u n c i l o f Canada's p o s t graduate b u r s a r y g r a n t e d i n 1954.  1. A SAMPLING-TYPE FUNCTION GENERATOR AND FOUR-QUADRANT ANALOG MULTIPLIER I.  Introduction  There i s a d e f i n i t e need f o r an economical  electronic  computer o f s u f f i c i e n t a c c u r a c y f o r s o l v i n g complex e n g i n e e r i n g problems.  U s u a l l y t h e g r e a t e s t expense o f such  a computer l i e s i n t h e f u n c t i o n g e n e r a t o r and i n t h e p r e c i s i o n components r e q u i r e d f o r r e a s o n a b l e  accuracy.  T h i s t h e s i s c o v e r s t h e b a s i c d e s i g n o f a s a m p l i n g type f u n c t i o n g e n e r a t o r and the complete d e s i g n o f a f o u r quadrant  analog m u l t i p l i e r w i t h the exception o f t h e t i m i n g  circuits.  The d e s i g n o f the t i m i n g c i r c u i t s was u n d e r t a k e n  under a s e p a r a t e t h e s i s by J.S. F i o r e n t i n o . The e l e c t r o n i c c i r c u i t r y c o n t a i n s a number o f g a t e s , f l i p - f l o p s , comparators, d.c. a m p l i f i e r s , e t c .  The  a m p l i f i e r s are P h i l b r i c k operation p l u g - i n u n i t s . * I t was  d e c i d e d t h a t a l l o t h e r s t a n d a r d c i r c u i t s such as g a t e s ,  f l i p - f l o p s and comparators would a l s o be b u i l t as p l u g - i n units.  The g e n e r a l c i r c u i t r y i s shown i n b l o c k form f o r  convenience and i s b u i l t up o f t h e s t a n d a r d p l u g - i n u n i t s . F i g u r e 1 shows t h e symbols a s s i g n e d t o t h e s e u n i t s .  See  appendix.  Philbrik operational dc amplifier  Philbrick operational dc amplifier  »> Plip-Plop  Delay Plip-Plop  Triode gate  conducting (closed) non-conducting (open) Diode Gate  Cathode follower Blanking Phantastron  Inverter  -A/WM-  *- Multiar  HI"  Integrator  Pig. 1  Pulse Amplifier Symbols f o r computer u n i t s .  Storage Unit IV)  II  P r i n c i p l e o f Operation  The b a s i c o p e r a t i o n o f t h e f u n c t i o n generator, i s t o g e n e r a t e a r e p e t i t i v e waveform r e p r e s e n t i n g a l l f u n c t i o n s t o be generated and then o b t a i n t h e r e q u i r e d o r d i n a t e  values  by s a m p l i n g t h e waveform. The s i m p l e s t method o f g e n e r a t i n g t h e r e q u i r e d waveform i s by means o f f i l m and an o p t i c a l , s c a n n i n g T h i s i s t h e method used i n the present  system.  i n v e s t i g a t i o n . Each  f u n c t i o n t o be g e n e r a t e d i s photographed on 35 mm. f i l m and mounted i n a s t a n d a r d 35 mm. frame which i s f a s t e n e d t o t h e rim of a rotating disk.  The f u n c t i o n s a r e drawn so t h a t they  a l l have t h e same maximum.  The f i r s t frame on t h e d i s k i s  used f o r a u t o m a t i c c a l i b r a t i o n and c o n t a i n s t h e z e r o l e v e l Figure 2  and t h e maximum l e v e l o f t h e f o l l o w i n g f u n c t i o n s .  shows t h e c a l i b r a t i o n frame and t h e f i r s t f u n c t i o n frame t o g e t h e r w i t h t h e p u l s e sequence w h i c h o p e r a t e s the following circuitryo A narrow beam o f l i g h t f r o m an o p t i c a l system i s passed t h r o u g h the n e g a t i v e s onto a photo-tube. of t h e photo-tube then r e p r e s e n t s  The output  the o r d i n a t e o f a l l t h e  f u n c t i o n s i n a t i m e - s e q u e n t i a l manner. The  l i n e a r i t y o f t h i s method depends on t h e u n i f o r m i t y  of t h e p h o t o - e l e c t r i c e f f e c t o v e r t h e s u r f a c e o f t h e phototube.  T e s t s made on a commercial t y p e 917  t h a t the departure  photo-tube show  from l i n e a r i t y i s about 3#»  This could  be reduced by p l a c i n g a mask i n t h e l i g h t p a t h . By c a r e f u l s h a p i n g o f t h e mask t h e e r r o r c o u l d be made v e r y s m a l l .  Po marker p u l s e P1,P3«P5 - t r i g g e r p u l s e s o b t a i n e d from f u n c t i o n frames P2 d e l a y e d p u l s e d e r i v e d from P I P4 m u l t i a r p u l s e from t i m i n g c i r c u i t s P6 sampling pulse from t i m i n g c i r c u i t s P7 d e l a y e d p u l s e d e r i v e d from P6 P8 m u l t i a r p u l s e from m u l t i p l i e r P9 d e l a y e d p u l s e d e r i v e d from P8  P i g . 2» C a l i b r a t i o n and f u n c t i o n frames on scanning d i s k  a  However, the n o n - l i n e a r  c h a r a c t e r i s t i c o f t h e photo-  tube i s t h e one b i g d i s a d v a n t a g e o f t h e o p t i c a l system.  The  i n p u t i s e s s e n t i a l l y an open l o o p and must be c a l i b r a t e d f o r each photo-tube.  I t s h o u l d be p o s s i b l e t o connect t h e i n p u t  i n t o a c l o s e d l o o p by u s i n g a s e r v o t o p o s i t i o n t h e mask a u t o m a t i c a l l y , s i n c e the i n t e r n a l c i r c u i t r y i s a r r a n g e d t o be s e l f - c a l i b r a t i n g and c a p a b l e o f p r e c i s i o n o p e r a t i o n . The output o f t h e photo-tube i s a m p l i f i e d by a d.c. amplifier.  The z e r o l e v e l v o l t a g e ( E ) i s h e l d and f e d back m  to t h e i n p u t o f t h e a m p l i f i e r by a system o f g a t e s and h o l d i n g circuits. for  T h i s s e t s the z e r o l e v e l and a u t o m a t i c a l l y c o r r e c t s  amplifier d r i f t .  I f the output o f t h e photo-tube  rises  above E , the ouput o f t h e a m p l i f i e r i s p o s i t i v e , and i f i t m  f a l l s below E , t h e output i s n e g a t i v e . m  The b l o c k diagram f o r the f u n c t i o n g e n e r a t o r u n i t i s shown i n F i g u r e " 3 * The s i g n a l coming from t h e photo-tube a m p l i f i e r i s d i r e c t e d i n t o t h r e e channels 1, 2, 3, and t h e t i m i n g c i r c u i t c h a n n e l D.  Channel 3 i s the a u t o m a t i c b i a s c i r c u i t and  o p e r a t e s as d e s c r i b e d below.  When t h e c a l i b r a t i o n frame i s  scanned, p u l s e P I o c c u r s a t the b e g i n n i n g o f t h e frame. T h i s p u l s e makes t r i o d e gate TG2 c o n d u c t i n g and diode g a t e LG 15 non-conducting.  When TG2 c o n d u c t s , t h e feedback l o o p o f t h e  holding c i r c u i t closes.  The s t o r a g e u n i t i s then a b l e t o  charge up t o t h e v o l t a g e - E . A second p u l s e , P 2 , makes m  TG 2 n o n - c o n d u c t i n g , thus b r e a k i n g t h e feed-back l o o p and l e a v i n g t h e s t o r a g e u n i t charged t o - E T h e  same p u l s e opens  Pig.  %  F u n c t i o n g e n e r a t o r assembly  7.  DG 1 5 and f e e d s - E  back t o t h e photo-tube  m  amplifier.  The a m p l i f i e r now h a s an output o f z e r o v o l t s f o r a n i n p u t of E  m  volts.  The c a l i b r a t i o n o c c u r s once i n e v e r y  r e v o l u t i o n o f the f u n c t i o n d i s k .  T h i s s i m p l e method  s o l v e s t h e problem o f d r i f t and z e r o - l e v e l c a l i b r a t i o n . The purpose o f c h a n n e l 1 w i l l become more apparent when t h e m u l t i p l i e r i s d i s c u s s e d .  I t s task i s to store the  maximum p o s i t i v e v a l u e o f t h e f u n c t i o n s and t o g e n e r a t e a sweep w h i c h i s needed f o r t h e m u l t i p l i e r . As t h e c a l i b r a t i n g frame i s scanned by t h e photo-tube, the  s t o r a g e u n i t becomes charged t o - E .  The p u l s e P 3  m  opens t h e second h a l f d f t h e t r i o d e gate TG 1 a l l o w i n g t h e s t o r a g e u n i t t o d i s c h a r g e t o - E ^ i n t h e case when i t s former charge o f - E was l a r g e r t h a n -E^. m  The p u l s e P 4  c l o s e s t h e gate l e a v i n g t h e s t o r a g e u n i t charged t o - E J J . The R ^ i c o m b i n a t i o n produces t he sweep r e q u i r e d by t h e multiplier. ing,  The p u l s e P 7 makes t h e gate DG 7 non-conduct-  thus i n i t i a t i n g t h e sweep, and P 8 r e t u r n s i t t o t h e  ground.. The ouput o f c h a n n e l 1 t h e n goes t o t h e m u l t i p l i e r c i r c u i t and i t s v a l u e i s - E ^ K ^ t ) . Channel 2 i s the f u n c t i o n c i r c u i t .  Gates DG 8, 9, and  1 0 become c o n d u c t i n g when t h e f u n c t i o n frame b e g i n s , t h a t i s a t P5«  A t the d e s i r e d a b s c i s s a , determined by t h e  t i m i n g c i r c u i t , P6 i s generated.  T h i s p u l s e makes t h e above  mentioned g a t e s n o n - c o n d u c t i n g , t h u s l e a v i n g the condenser C  2  charged t o t h e i n v e r t e d o r d i n a t e v o l t a g e - E . F  The  p u l s e P 7 makes DG 1 1 and 1 2 c o n d u c t i n g , t h u s s t a r t i n g a sweep a t B w i t h v a l u e + E . N ( t ) .  T h i s sweep i s i d e n t i c a l t o  8. t h e one I n c h a n n e l 1, as w i l l he shown l a t e r . DG 10, 9,  Since  a u i 8 a i e s t i l l n o n - c o n d u c t i n g t h e sweep a t C i s  i n v e r t e d , i . e . -rE^BXt).  The c i r c u i t diagram o f t h e m u l t i p l i e r i s shown i n F i g u r e 4.  The m u l t i a r comparators  (M) o p e r a t e o n l y i f the  r e f e r e n c e v o l t a g e , E, i s more p o s i t i v e t h a n t h e sweep input.  The o r i g i n a l s t a t e o f DG 16 i s n o n - c o n d u c t i n g and  DG 17 c o n d u c t i n g .  I f E i s negative the inverted p o s i t i v e  v o l t a g e , -E, i s a p p l i e d t o M4.  S i n c e the second i n p u t of  M4 i s a t ground p o t e n t i a l , H4 g e n e r a t e s a p u l s e .  The p u l s e  from M4 o p e r a t e s f l i p - f l o p FF8 w h i c h c l o s e s DG 16 and opens DG 17, t h u s a p p l y i n g t h e n e g a t i v e v o l t a g e , E, t o M3. p u l s e from M4 a l s o opens DG 14 and c l o s e s DG 13.  The  These  g a t e s l e a d t o t h e s t o r a g e c i r c u i t s shown i n F i g u r e 5° The sweep - E ^ t ) from c h a n n e l 1 s t a r t s a t P7 and i s a p p l i e d t o M3.  At t h e i n s t a n t E - E ^ ( t ) a p u l s e P8 I s g e n e r a t e d .  T h i s p u l s e opens DG 11 shown i n F i g u r e 3» thus s t o p p i n g t h e sweep - E ^ N ( t ) , l e a v i n g t h e s t o r a g e c i r c u i t charged t c -E^H(t)o S i n c e t h e sweep i s stopped a t t h e i n s t a n t E = EjgNtt), and s i n c e t h e N(t) of channel 1 i s i d e n t i c a l w i t h t h e N ( t ) o f EEc h a n n e l 2, i t i s o b v i o u s t h a t t h e v a l u e s t o r e d i s - — S . , I f E i s p o s i t i v e , diode gate DG 13 i s open and DG 14 i s c l o s e d .  The v o l t a g e s t o r e d w i l l t h e n be  EE£ . M  E  From the above i t c a n be seen t h a t f o u r - q u a d r a n t m u l t i p l i c a t i o n has been a c h i e v e d .  The p u l s e P9 r e s e t s the g a t e s  DG 12, 13, 14, 16, 17 as shown i n t h e diagram.  E  K2  -W  P9  P(~)-N P(^)-C  M 3  A  Pigo  4«  P(~)  M 4  *8  P o u r Quadrant  F F  Multiplier.  8  P(+)  10. The s t o r a g e system w h i c h i s shown i n F i g u r e 5 c o n s i s t s o f a bank o f s t o r a g e u n i t s o p e r a t e d by a c o u n t e r . PO s e t s the f i r s t f l i p - f l o p t o make t h e f i r s t c h a n n e l open and s e t s a l l t h e o t h e r f l i p - f l o p s r e m a i n i n g channels a r e c l o s e d . r e f e r e n c e marker on t h e disko  A pulse  storage so t h a t t h e  The p u l s e PO comes f r o m a The f u n c t i o n g e n e r a t e d  the f i r s t frame i s s t o r e d i n the f i r s t s t o r a g e u n i t .  from The  p u l s e P9 a t t h e end o f t h e m u l t i p l i c a t i o n s e t s t h e f i r s t s t o r a g e c h a n n e l i n t h e c l o s e d p o s i t i o n and opens the second.  The o p e r a t i o n r e p e a t s u n t i l a l l the f u n c t i o n s have  been p r o c e s s e d and s t o r e d .  12,. Ill The  c i r c u i t s a r e designed t o make use o f s t a n d a r d  components. K2-X  D e t a i l e d C i r c u i t Design.  The d.e. a m p l i f i e r s used a r e P h i l b r i c k model  and K2-W o p e r a t i o n a l a m p l i f i e r s .  These a m p l i f i e r s  have a g a i n o f 30,000 and 15,000 r e s p e c t i v e l y .  The K2-W  output i s + 50 v o l t s a t + 1 ma. and t h e K2-X maximum output i s + 100 v o l t s a t i 2 ma.  The a m p l i f i e r s a r e used  w i t h 100# f e e d back i n p r a c t i c a l l y a l l c a s e s .  This provides  maximum s t a b i l i t y . (l)  Scanning Unit The  s c a n n i n g u n i t c o n s i s t s o f two p a r t s j  a  r o t a t i n g frame h o l d e r o r d i s k and an o p t i c a l system. "The disk consists of a  s i x t e e n - i n c h diameter, one-quarter i n c h  t h i c k , s t e e l d i s k , w i t h an o u t e r r i m o f aluminum t h r e e i n c h e s wide.  The heavy c e n t r e o f t h e d i s k a c t s as a f l y - w h e e l ,  smoothing out any v a r i a t i o n s i n t h e speed o f t h e d r i v i n g motor.  The aluminum r i m c o n t a i n s  f u n c t i o n frames.  the c l i p s t o hold eighteen  F i g u r e 6 shows t h e c o n s t r u c t i o n .  it  F i g u r e 6.  n  Rotating function disk.  aluminum  13. The d i s k i s d r i v e n by a o n e - t e n t h horsepower. 700 rpm, 1 1 0 - v o l t d i r e c t - c u r r e n t shunt motor.  The d r i v e i s  transmitted through a rubber belt.which a l s o helps t o smooth out any v a r i a t i o n s i n t h e speed o f t h e motor. The l i g h t source i s a 6 - v o l t , d i r e c t c u r r e n t , s t r a i g h t , v e r t i c a l f i l a m e n t lamp, which g i v e s an i n t e n s e uniform l i g h t .  vertically  The l i g h t i s * f o c u s e d by c y l i n d r i c a l  lenses  so t h a t t h e f o c a l p o i n t o f t h e narrow beam i s a t t h e f i l m . The type 917 photo-tube i s s i t u a t e d on t h e o p p o s i t e of the d i s k to the l i g h t source.  side  F i g u r e 7 shows t h e complete  m e c h a n i c a l assembly.  r o t a t i n g d i s k and f i l m holder  o  F i g u r e 7.  S c a n n i n g U n i t Assembly.  The output o f t h e photo-tube v a r i e s w i t h t h e amount o f l i g h t i t r e c e i v e s and t h e r e f o r e r e p r e s e n t s  the o r d i n a t e o f  14 the f u n c t i o n s  p a s s i n g t h r o u g h t h e beam o f l i g h t .  o  That i s  the output o f t h e tube i s amplitude modulated by t h e l i g h t beam  0  (2)  Photo-tube A m p l i f i e r . The a m p l i f i e r c o n s i s t s o f the two P h i l b r i c k  K2-X d.c. a m p l i f i e r s i n s e r i e s .  These have two i n p u t s .  The p o s i t i v e i n p u t , . 1 , i s used when i n v e r s i o n i s r e q u i r e d and t h e n e g a t i v e i n p u t . .2, when i n v e r s i o n i s n o t r e q u i r e d . In the present a p p l i c a t i o n , i n v e r s i o n i s n o r m a l l y required  because n e g a t i v e feed-back i s used.  The p o s i t i v e  input i s then used f o r balance c o n t r o l . The c i r c u i t diagram o f t h e photo-tube a m p l i f i e r appears i n F i g u r e 8. R l , R2 R 3 , R7  0  R5, R6  -  1 Megohm  - 470 K i l o h m s  B#, R8 R2 ,—'WWvV-  47 K i l o h m s  Rl  R5-  M W A M - ~  K2-X  F i g u r e 8.  Photo-tube  Amplifier.  15. The ouput o f t h e photo-tube v a r i e s from z e r o t o a p p r o x i m a t e l y 1 v o l t as t h e f u n c t i o n v a r i e s between i t s n e g a t i v e and p o s i t i v e extremes.  The output o f t h e a m p l i f i e r  s h o u l d r e p r e s e n t the f u n c t i o n , t h e r e f o r e a f e e d b a c k system was d e s i g n e d t o g i v e z e r o output f o r z e r o i n p u t l e v e l , E<> m  The output o f each a m p l i f i e r i s f e d back t o t h e i n p u t t o g i v e a g a i n o f 10.  The two i n s e r i e s t h e n produce a  g a i n o f 100. The g a i n o f 100 was chosen so t h a t t h e maximum photo-tube s i g n a l , a p p r o x i m a t e l y 1 v o l t , would n o t o v e r l o a d t h e a m p l i f i e r s which have a maximum output range o f -50 t o + 50 v o l t s . (3)  H o l d i n g System o f Channels 1 and 3. Channels 1 and 3 o p e r a t e p r i n c i p a l l y as v o l t a g e -  clamping c i r c u i t s .  The b l o c k diagram o f t h e h o l d i n g system  i s shown i n F i g u r e 9«  F i g u r e 9«  H o l d i n g system o f Channel 1 and 3»  16. When a v o l t a g e e^ i s a p p l i e d as shown, and t h e t r i o d e gate i s made c o n d u c t i n g , t h e condenser C charges up t o t h i s voltage.  The a m p l i f i e r s a r e connected so as t o p r o v i d e  i n v e r s i o n a t t h e output o f t h e h o l d i n g a m p l i f i e r . That i s , t o o b t a i n n e g a t i v e feed-back between t h e i n p u t o f K2=-W and the  output o f t h e h o l d i n g a m p l i f i e r , t h e p o s i t i v e (+) i n p u t  o f K 2 - W and t h e n e g a t i v e (<=>) i n p u t o f t h e h o l d i n g a m p l i f i e r must be used.  I f t h e g a t e i s made n o n - c o n d u c t i n g  the feed-back l o o p i s broken and the condenser C i s l e f t charged t o =e^  0  Any v a r i a t i o n i n t h e i n p u t no l o n g e r  a f f e c t s the o u t p u t .  I f t h e charge b e g i n s t o l e a k from t h e  condenser, t h e change i n p o t e n t i a l i s f e d back t o t h e i n p u t of t h e h o l d i n g a m p l i f i e r .  T h i s t e n d s t o make t h e ouput  return to i t so r i g i n a l state. The d e t a i l e d c i r c u i t diagram o f t h e h o l d i n g system appears i n F i g u r e 10. (4)  H o l d i n g system o f Channel 2. The h o l d i n g c i r c u i t u s e d i n c h a n n e l 2 must be one  w h i c h f o l l o w s the v a r y i n g f u n c t i o n v e r y r a p i d l y .  I t need  not h o l d t h e f u n c t i o n f o r a s l o n g as t h e h o l d i n g c i r c u i t s i n channels 1 and 3.  E s s e n t i a l l y , a condesner i s charged  t h r o u g h a d.e. a m p l i f i e r .  However, t h e condenser must be  s m a l l i n o r d e r t o charge r a p i d l y .  At f i r s t a P h i l b r i c k  K2-W a m p l i f i e r was used t o charge t h e condenser, b u t t h i s proved t o be t o o slow because o f i t s low c u r r e n t output w h i c h i s l i m i t e d t o one ma.  +300 M a i n C h a s s i s Bus  B  R ! 2  V  O—VWv—•—WW  loOM 0.1#  R^s  4.7M 10$  10Z P o t , - M a l l o r y l o O -~10# 220K 10$ 2.2M 10$ 470K 10$  R^s  1500X110^  68K> 10$ R  i  R,  120K 10# 1 w a t t 2.7M 10#  10% 10$  33K l  13'  15K  A l l resistors are watt unless otherwise noted.  K2-V  -^)—I  S  *-  REPRESENTATION  0 0.5 MFD P o l y s t y r e n e (Low Leakage) 5 50 MMFD 600 VDC _ ^, _ , , „ For bidirectional control (positive 1 10 MMPD 600 TO and n e g a t i v e v o l t a g e s t o r a g e ) b o t h 1 470 MMPD 600 VDC c o n t r o l g r i d s o f TG a r e c o n n e c t e d i n series. F i g u r e 10g VOLTAGE STORAGE AND HOLDING CIRCUIT. 0  m  18. Suppose t h e v a l u e of the s t o r a g e condenser I s microfarads.  I f the condenser i s charged by the  .001 Z2-W  a m p l i f i e r , the time o f c h a r g i n g i s as f o l l o w s s 0 = q/v  A~£_±  =  v  Therefore  t = Cv/i  If  V = 50 v o l t s and i = 1  ma.  —"5  t = .001 x 50 x 10  - 50 m i c r o - s e c o n d s .  S i n c e t h i s t i m e i s too l o n g the c i r c u i t i n F i g u r e was  developed.  I n t h i s c i r c u i t a cathode f o l l o w e r i s  used i n s i d e the feed-back l o o p . capable o f c a r r y i n g 10 ma. up t o 50 ma.  11  S i n c e the 12AU7 tube i s  average c u r r e n t and  c u r r e n t p u l s e s , i t was  as a cathode f o l l o w e r .  found t o be  The b i a s t o the K2-W  supplying satisfactory  amplifier.is  a d j u s t e d so t h a t z e r o i n p u t g i v e s zero output o f the cathode f o l l o w e r .  F i g u r e 11.  H o l d i n g c i r c u i t of Channel 2.  19< Suppose a n e g a t i v e s t e p o f 50 v o l t s i s a p p l i e d a t (a).  The cathode f o l l o w e r i s then made t o conduct v e r y  strongly, Then  say about 50 ma. t = £S = .001 x 10°^ = 1 m i c r o - s e c o n d , i  I f a p o s i t i v e s t e p i s , a p p l i e d t o ( a ) t h e cathode ?  follower  i s c u t o f f and the-'condenser i s charged from  the -300 v o l t source t h r o u g h the 30Z r e s i s t o r , . c o n s t a n t , ^O*,,,  o  f  ^  the v o l t a g e a c r o s s C v o l t a g e be e^„  e  2  c i r c u i  be e  "^  i  s  30 microseconds.  The time Let  and t h e -300 v o l t s u p p l y  2  The c h a r g i n g t i m e o f t h e condenser may be  found as f o l l o w s s 2 ^ 2 e^TpT 1 + pR 06  ( p )  R  2  e  2  =  e  1  = -300 volts  2  50 v o l t s maximum  e ( t ) = e ^ t ) (1 - e" / 2 2) >t  R  C  2  e  t = R C 2  Therefore  2  l  I n 5/6  t = 5.088 x 10 ' = 5 micro-seconds < >  Since the f u n c t i o n involved  w i l l p r o b a b l y n e v e r be a  s t e p t y p e , t h e c h a r g i n g time w i l l be l e s s t h a n 5 m i c r o seconds and may be c o n s i d e r e d t o be n e g l i g i b l e .  20. The d i o d e g a t e s i n t h e c i r c u i t a r e used t o i s o l a t e the condenser and l e a v e i t charged t o t he v o l t a g e r e p r e s e n t i n g the o r d i n a t e a t the i n s t a n t o f s a m p l i n g .  The purpose o f t h e  p a r a l l e l feed-hack i s t o a l l o w t h e a m p l i f i e r t o he used as the i n v e r t e r i n Channel 2 when c h a r g i n g has been completed,, (6)  Inverters, The i n v e r t e r s c o n s i s t o f a K2-W a m p l i f i e r w i t h  100$ feed-back g i v i n g a g a i n o f one. Channel 1 i s shown i n F i g u r e 12.  The i n v e r t e r i n  I  R2  bias F i g u r e 12.  I n v e r t e r o f Channel 1,  As mentioned e a r l i e r , t h e i n v e r t e r i n Channel 2 employs t h e same a m p l i f i e r t h a t i s u s e d t o charge t h e h o l d i n g condenser.  T h i s can b e done because t h e h o l d i n g a m p l i f i e r  i s i n o p e r a t i v e d u r i n g t h e time t h a t t h e i n v e r t e r i s needed,, The c i r c u i t diagram f o r t h e Channel 2 i n v e r t e r i s shown i n F i g u r e 13.  The g a t e s a r e n o n - c o n d u c t i n g and t h e r e f o r e t h e  K2-W a m p l i f i e r and t h e cathode f o l l o w e r a c t as an i n v e r t e r .  21.  input  -WVvW  RloR2-200K  R3 - 400K  output  F i g u r e 13. (7)  I n v e r t e r o f Channel 2.  Gateso Two t y p e s o f g a t e s were i n v e s t i g a t e d ;  the t r i o d e  p  g a t e and t h e s i x - d i o d e b r i d g e - t y p e g a t e  D  The g a t e s must  be b i - d i r e c t i o n a l and i n most c a s e s be c a p a b l e o f p a s s i n g voltages w i t h great accuracy.  That i s  9  the g a i n t h r o u g h  t h e gate s h o u l d be as c l o s e as p o s s i b l e t o u n i t y . A d o u b l e - t r i o d e c a n be used as a b i - d i r e c t i o n a l g a t e , but i t i s e x t r e m e l y d i f f i c u l t , i f n o t i m p o s s i b l e t o o b t a i n 9  a c o n s i s t e n t l y accurate g a i n l e v e l through t h e gate.  The  o n l y c i r c u m s t a n c e s under w h i c h t r i o d e g a t e s c a n b e used a r e i n s i d e a feed-back l o o p , where a c c u r a c y i s n o t n e c e s s a r y . These were used i n t h e h o l d i n g systems o f Channels 1 and 2 as mentioned  previously.  I n most cases diode g a t e s a r e a n e c e s s i t y because a v o l t a g e must be p a s s e d a c c u r a t e l y .  The c i r c u i t diagram o f  -§ R2 -wvvw-  out  •I L £ 6AL5  R4  £ 6AL5  * 6AL5  i 6AL5 in  R l , R2, R3 - 1M R4 - I K  DG  Fig.  14. Diode g a t e  B - 300 v o l t s C - 60 v o l t s K 60 v o l t s  £ 6AL5  23. the d i o d e gate appears i n F i g u r e 14• d e s i g n e d to pass i  50 v o l t s maximum  ?  The gate i s s i n c e t h i s i s the  h i g h e s t v o l t a g e passed by the d.c. a m p l i f i e r s . v o l t a g e s a r e ± 60 v o l t s .  The  control  The t u b e s used are t h r e e 6AL5's.  The a c c u r a c y o f the gate was t e s t e d as shown i n F i g u r e 15. The r e s u l t s a r e g i v e n i n Table 1.  conducting  F i g u r e 15.  T e s t Setup f o r t h e Diode Gates.  24. Table 1. Ein  (volts)  Ein-Eo ( v o l t s )  .3.00 5.00 10.0 20.0 30.0 40.0 50.0 60.0 -60i>0 -50.0 -40.0 -30.0 -20*0 -10.0  % relative error  .01774 .03898 .05255 .07909 .10720 .13425 .16320 .19157 .1608 .12615 .09119 .05690 .02824 .00079  .59# .78# .53# .39# ,35# .33# .33# .32?S .27# .259& .23# .19# .14# .008#  The g r e a t e s t r e l a t i v e e r r o r occurs a t an i n p u t o f 5 volts.  The g a i n a t t h i s p o i n t i s s  G = f a = 5 . 0 0 - .03898 Bin 5.00 (8)  =  ,992  Sweep C i r c u i t s . The sweep c i r c u i t s o f Channel 1 and 2 are d i f f e r e n t ,  but the sweeps are i d e n t i c a l . The sweep c i r c u i t o f Channel 1 i s an RG network w i t h a diode gate from t h e output t o ground. the c i r c u i t .  F i g u r e 16 shows  The h o l d i n g c i r c u i t prevents the i n p u t t o the  sweep from changing as the sweep p r o g r e s s e s . the sweep i s e ( t ) = E ^ l - e " Q  t / / R  l l)„ C  The e q u a t i o n of  25  B  M  Rl • rtwvw*  From holding circuit  R l - 1M C I - .001 m i c r o f a r a d s  F i g u r e 16. Sweep c i r c u i t o f Channel 1* The time c o n s t a n t , R^C^, i s chosen as one m i l l i - s e c o n d because o f the speed o f s c a n n i n g .  The frames a r e e i g h t i n c h e s  from t h e c e n t r e o f t h e d i s k so t h a t a t 700 rpm t h e l i n e a r speed o f t h e frame i s a p p r o x i m a t e l y 560 i n c h e s p e r second. The frame i s about l£ i n c h e s w i d e , t h e r e f o r e t h e t i m e r e q u i r e d f o r one f u n c t i o n t o be scanned i s 2.5 m i l l i - s e c o n d s . The t i m e between frames i s 1.5 m i l l i - s e c o n d s .  I f the f u n c t i o n  i s sampled n e a r t h e end o f t h e frame, t h e r e i s 1.5 m i l l i seconds f o r t h e sweep and comparators t o a c t b e f o r e t h e n e x t function begins.  T h e r e f o r e , t h e sweep t i m e - c o n s t a n t was chosen  t o be one m i l l i - s e c o n d . The gate s t a r t s t h e sweep when i t i s made n o n - c o n d u c t i n g and s t o p s t h e sweep when i t i s made conducting. The sweep c i r c u i t of Channel 2 cannot be a s i m p l e RC network. relatively  The r e a s o n i s t h a t o r d i n a t e v o l t a g e s m a l l condenser.  i s h e l d on a  When t h e sweep s t a r t s , t h e charge  26. on t h e condenser i s d r a i n e d o f f , t h e r e b y r e d u c i n g E^. Hence some means o f c o r r e c t i n g f o r t h e v o l t a g e drop must be f o u n d .  The s o l u t i o n i s t o use a d i r e c t - c u r r e n t  a m p l i f i e r w i t h c a p a c i t a t i v e feed-back.  The c i r u i t  appears  i n F i g u r e 17.  e. =b C2 P5-C P6-N  P5-C P8-N  F i g u r e 17.  Sweep C i r c u i t o f Channel 2.  An a n a l y s i s o f the c i r c u i t w i t h gate DG 11 c o n d u c t i n g and DG 10 and DG 12 n o n - c o n d u c t i n g , g i v e s t h e f o l l o w i n g s  Since E  i s e s s e n t i a l l y zero because o f t h e l a r g e g a i n  27< The c a p a c i t o r  d i s c h a r g e s t h r o u g h Ego  Hence, i f  B i s t h e o r i g i n a l v o l t a g e on C^, e  Kt) -  B  e  "  t  /  E  2  °  2  E P + 1 *2°Z  and  e-]_(p)  Therefore  . (p) = -  = - ^ _  2  (  ) '22  T a k i n g t h e i n v e r s e L a p l a c e Transforms  0 Ct) = «E  °3  ( ! _ e-VVfe)  I f 0, = C, 2 3, e ( t ) = - E ( l - e 2°^2 ) R  2  which i s t h e same a s t h e sweep used i n Channel 1 except f o r the s i g n .  was determined by t h e r e q u i r e m e n t s  h o l d i n g c i r c u i t and was s e t a t .001 m i c r o f a r a d .  of t h e In a  p r e c e d i n g paragraph i t was found t h a t t h e sweep t i m e c o n s t a n t was one m i l l i - s e c o n d . T h i s r e q u i r e s t h a t R2 must be 1 megohm i n b o t h sweeps. (8)  Comparator. Comparators o f the m u l t i a r type were chosen  because o f t h e i r i n h e r e n t s i m p l i c i t y and a c c u r a c y .  The  c i r c u i t diagram appears i n F i g u r e 18. The n e g a t i v e r e f e r e n c e v o l t a g e on t h e p l a t e s -of V I keeps the diode f r o m conducting.  The tube V2 i s n o r m a l l y  s t r o n g l y and V3 i s c l o s e t o c u t o f f .  conducting When t h e  176 AW2F or 134 BW2F  381  F i  R l - 100Z 4 R2 - 4o7M I R3.R8 - 53K 1 R4,R9 - 56Z 1 W R5 - 100K R6 - 33K R7 - 1M C1,G3 -'.001 >ufd 02,04 - . l > u f d 05 -.01y*fd  g » 18. C i r c u i t d i a g r a m o f m u l t i a r comparator  v  29*  f a l l i n g sweep r e a c h e s e q u a l i t y w i t h the r e f e r e n c e v o l t a g e V I c o n d u c t s , thus c o m p l e t i n g t h e r e g e r a t i v e l o o p .  9  The  r e g e n e r a t i o n d r i v e s t h e g r i d o f V2 t o c u t - o f f v e r y r a p i d l y and as a r e s u l t we get a l a r g e p o s i t i v e p u l s e a t t h e p l a t e o f V2.  The tube V3 i s used t o i n v e r t t h e p u i s e ^ a l t h o u g h a  p u l s e t r a n s f o r m e r c o u l d a l s o be used f o r p u l s e i n v e r s i o n . The charge on C I d i s c h a r g e s t h r o u g h R2 and makes V2 conducting again.  T h i s a g a i n c l o s e s the r e g e n e r a t i v e l o o p  and causes another p u l s e .  A t r a i n of pulses occurs  until  the sweep r e t u r n s t o a l e s s n e g a t i v e v a l u e t h a n t h e reference voltage.  I n a c t u a l p r a c t i c e the pulse i s a p p l i e d  t o a f l i p - f l o p w h i c h t u r n s on t h e gate DG- 7, t h u s the sweep and r e t u r n i n g i t t o ground. i n i t i a l p u l s e i s generated DG 7  stopping  T h e r e f o r e o n l y the  s i n c e V I c u t s o f f as soon as  conducts. The r i s e time o f the p u l s e i s o f the o r d e r o f 1 t o 2  microseconds and o c c u r s a g a i n as soon as the sweep v o l t a g e i s equal t o the reference voltage. 230  volts.  The p u l s e h e i g h t i s  30. 17  Accuracy Test of M u l t i p l i e r .  The c i r c u i t as a whole was not tested because no precision components or power supplies were available. However, a test procedure i s desirable f o r future t e s t i n g . The test set-up i s shown i n Figure 20. Aa was shown e a r l i e r the equation of the sweep i n channel 1 i s e ^ t ) = B (1 - e -  t / R  l°l)  The equation of the sweep i n channel 2 i s  < i - e-*/*2*2)  e (t) - • U 2  !  3  I f the sweeps are to be equal, EgGg must equal R C 1  1  and Og equal C j • RgCg was matched to R^Pl  a  s  i  s  s  n  o  w  n  i n Figure 19 <  01 Rl  r—-WVVVV-Cvv3lvvuL  / V ) iooo cps  oscilloscope  R2  bias Figure 19.  C i r c u i t used to match Time Constants.  32.  was a d j u s t e d u n t i l t h e o s c i l l o s c o p e showed no 1000 c y c l e o u t p u t .  Therefore  = R 2° C  T  h  e  K 2  2  ™^  amplifiers introduce l i t t l e e r r o r since t h e i r gains are so l a r g e . I t would he extremely d i f f i c u l t t o match C  2  T h e r e f o r e a method t o overcome t h i s was d e v i s e d . input t o the  R C 2  t o C^. The  network must be p o s i t i v e i n o r d e r t o  2  produce a n e g a t i v e sweep.  T h e r e f o r e , an i n v e r t e r i s  i n t r o d u c e d as shown i n F i g u r e 20. The i n p u t t o t h e R C r sweep i s t h e n E — . Hence t h e output o f t h e sweep i s l 2  2  0  r  ~  E  ^ ^ ( l °3  l-e-  t / R  2°2).  r  If  r C 2  2  = r ^ ,  t h e sweep w i l l be - E ( l -  w h i c h i s the same as the  R^C-L  sweep.  The  e~ '*2 Z) X  G  r C , r^C^ 2  2  time c o n s t a n t s were matched i n t h e same way a s i s shown i n Figure 19. The m u l t i p l i c a t i o n m u l t i a r i s KL, and M2 i s t h e peak detecting multiar.  The p u l s e g e n e r a t o r produces a p u l s e P I  w h i c h o p e r a t e s the g a t e s as shown i n F i g u r e 20, t h e r e b y i n i t i a t i n g b o t h sweeps.  The n e g a t i v e r e f e r e n c e v o l t a g e o f  KL i s s e t a t the d e s i r e d l e v e l o f m u l t i p l i c a t i o n , E^. When the R - ^ l  s w e e  P reaches e q u a l i t y w i t h E.^, KL produces a  p u l s e w h i c h s t o p s the sweeps. Some way o f measuring t h e v a l u e o f t h e  R C 2  2  sweep had  t o be found, s i n c e no s t o r a g e c i r c u i t was a v a i l a b l e . second m u l t i a r , M2, i s i n t r o d u c e d . a n d  A  i t s reference voltage  33. i s r a i s e d from a l a r g e n e g a t i v e v a l u e u n t i l i t generates a p u l s e which i s seen on the scope. e q u a l t o the peak o f t h e sweep.  At t h i s p o i n t E^ i s  The v o l t a g e s Eg and E^ are  t h e n compared on a s i m p l e b r i d g e as shown i n F i g u r e 2 0 and the v o l t a g e d i f f e r e n c e i s measured. absolutely accurate E  1  = Eg.  I f the m u l t i p l i e r i s  The r e s u l t s o f a t y p i c a l s e t  of r e a d i n g s a r e shown below. Table 2 . l  E  *2~*1  (Approaching from below t h e peak)  E  2 °  E  1  (Approaching from above t h e peak)  5  5.06  5.07  10  10.25  10o26  15  15.25  20  2 0 . 3 5  2 0 . 4 0  25  2 5 . 4 7  2 5 . 5 3  15.29  The above t e s t i s d e s i g n e d t o measure t h e a c c u r a c y o f the m u l t i p l i e r .  The way i n w h i c h t h e m u t l i p l i e r has been s e t  up i n t h i s case i n t r o d u c e s more e r r o r t h a n would the a c t u a l multiplier.  I n ihe example g i v e n above t h e f l i p - f l o p i s  l o a d e d by t h r e e g a t e s i n s t e a d o f one and, i n additions, the RgCg sweep i s stopped by making DG 1 2 c o n d u c t i n g i n s t e a d o f s t o p p i n g i t by making DG 1 1 non-conducting.  The d i o d e g a t e s  have a d e l a y o f 1 0 micro-seconds when made c o n d u c t i n g , but o n l y 1 t o 2 micro-seconds when made n o n - c o n d u c t i n g . T h e r e f o r e . the r e a d i n g s above do not i n d i c a t e t h e a c c u r a c y w h i c h i s o b t a i n a b l e , but they do show t h a t the t e s t i n g method i s satisfactory.  34 7  The p r o t o t y p e  Conclusion.  s c a n n i n g system t h a t was b u i l t  i n d i c a t e d t h a t the i d e a i s p r a c t i c a b l e . refinements analog  has  Further  w i l l be made as work p r o g r e s s e s  on  the  computer.  The m u l t i p l i e r and f u n c t i o n g e n e r a t o r  c o u l d not  f u l l y t e s t e d because the tuning c i r c u i t r y was  not  be  completed,  and p r e c i s i o n r e s i s t o r s and cmdensers were n o t a v a i l a b l e f o r the sweep and i n v e r s i o n c i r c u i t s .  Another f a c t o r  was t h e u n a v a i l a b i l i t y of w e l l r e g u l a t e d power s u p p l i e s . T h e . t e s t s on the m u l t i p l i e r d i d i n d i c a t e t h a t good a c c u r a c y can be  obtained.  (5) + 300  IN/5  HEATERS  A  6 »1 E  2  E  5  R  4  B  E  5 6  *7 E  8  • 150K  ( 3 ) - 300 6.3V  10$ t  .0 e 9  150K  10#  1 watt  0 O  470K  * watt  0 o  1.0M  10$ 10$ 10$ 10$ 10$ 10$  • 180K 0  s 68KI  2.2K  ft82K o  watt * watt * watt * watt  *  R  9  ^0  i 220K : 10.0M  10$  R11 . 1.5 M 1096 R 4.7M 10$ 12°  £ £ £ i  watt watt watt watt  > IN  +  K2-X  OUT  SYMBOL  15 MMPD 0.005 MPD O5 8 7.5 MMPD  APPENDIX:^  MODEL K2-X OPERATIONAL AMPLIFIER George A. P h i l b r i c k R e s e a r c h e s , I n c . (GAP/R)  \J1  Rl R2  .22M R7 R8 - .22M  RIO NE2  R8 *R6  ±02  7  H  IN  8 H  6.3V  1 3 4 + -300 GND IN VDC (REP)  P h i l b r i c k Model K2-W  R - 10K R l - 1M  5#  -  R9  C3  2  5%  R9 - •27M 5% RIO ,68M Rll 4.7M Rll 01 7.5 C2 500  01  :E2  _  NE2  HK  5%  .22M 5# R3 - 1M 2.2M R4 ..47M 5% R5 R6 10K  12AX7  /\—i\  - .22M  —  7.5  5  6 OUT  +300 VDC  Operational Amplifier  R  +300 VDC OUT  R e s i s t i v e method o f b i a s  Base Connections General S p e c i f i c a t i o n s GAIN: 15,000 DC, open-loop POWER REQUIREMENTS:  INPUT IMPEDANCE: Above 100 Megohms OUTPUT IMPEDANCE: Less t h a n 1 K open-loop below 1 ohm f u l l y f e d back DRIFT RATE: 5 mv p e r day, r e f e r r e d to the input  VOLTAGE RANGE: -50 VDC t o +50 VDC,at ouput & 4.5 ma a t +300 VDC both i n p u t s 4.5 ma a t -300 VDC INPUT CURRENT: 0.6 Amperes a t 6.3V L e s s t h a n 0.1 TUBE COMPLEMENT Microamp f o r 2 12AX7 e i t h e r input OUTPUT CURRENT: -1 ma t o +1 ma over f u l l v o l t a g e range. Appendix  37. Bibliography F i o r e n t i n o , • J.S., - " T i m i n g and C o i n c i d e n c e C i r c u i t r y f o r a Time-Sharing Analog F u n c t i o n G e n e r a t o r " M . A . S c T h e s i s . U n i v e r s i t y o f B r i t i s h Columbia, 1956*. M i l l m a n and P u c k e t t - " A c c u r a t e L i n e a r B i - d i r e c t i o n a l Diode Gates" - P r o c e e d i n g s o f the I.R.E., January 1955, pp. 29-37. Freeman and Parsons 7 "A Time-Sharing Analog M u l t i p l i e r " T r a n s a c t i o n s o f the I.R.E., P r o f e s s i o n a l Group on E l e c t r o n i c Computers, March 1954. K o r n and K o r n - " E l e c t r o n i c A n a l o g Computers", McGraw H i l l , 1952. W i l l i a m s and Moody - "Ranging C i r c u i t s , L i n e a r TimeBase Generators:and A s s o c i a t e d C i r c u i t s " I n s t i t u t e of E l e c t r i c a l Engineers Journal. Volume I I I A , Radio L o c a t i o n , 1946, pp.1188-1198.  

Cite

Citation Scheme:

    

Usage Statistics

Country Views Downloads
China 14 10
United States 8 1
France 4 0
Russia 3 0
Japan 2 0
Germany 2 6
Poland 1 0
Canada 1 0
Czech Republic 1 0
City Views Downloads
Unknown 11 6
Shenzhen 7 8
Beijing 7 2
Ashburn 3 1
University Park 2 0
Mountain View 2 0
Tokyo 2 0
Łódź 1 0
Saint Petersburg 1 0

{[{ mDataHeader[type] }]} {[{ month[type] }]} {[{ tData[type] }]}
Download Stats

Share

Embed

Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                        
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            src="{[{embed.src}]}"
                            data-item="{[{embed.item}]}"
                            data-collection="{[{embed.collection}]}"
                            data-metadata="{[{embed.showMetadata}]}"
                            data-width="{[{embed.width}]}"
                            async >
                            </script>
                            </div>
                        
                    
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:
http://iiif.library.ubc.ca/presentation/dsp.831.1-0105061/manifest

Comment

Related Items