29631AA(Model725).pdf part of Keithley 29631AA(Model725) 29631AA(Model725).pdf, Keithley 725 29631AA(Model725).pdf text manual preview

Text preview for : 29631AA(Model725).pdf part of Keithley 29631AA(Model725) Keithley 725 29631AA(Model725).pdf

Back to : 29631AA(Model725).pdf | Home

INSTRUCTION MANUAL
Programmable Current Source
Model 725

.
-
WARRANTY
We warrant each of our products to be free from defects in material
and workmanship. Our obligation under this warranty is to repair
or replace any instrument or part thereof which, within a year after
shipment, proves defective upon examination. We will pay local
domestic surface freight costs.
To exercise this warranty, write or call your local Keithley repre-
sentative, or contact Keithley headquarters in Cleveland, Ohio.
You will be given prompt assistance and shipping instructions.

REPAIRS AND
CALI BRATION
Keithley Instruments maintains a complete repair and calibration
service as well as a standards laboratory in Cleveland, Ohio.

A Keithley service facility at our Munich, Germany office is
available for our customers throughout Europe. Service in the
United Kingdom can be handled at our office in Reading. Addition-
ally, Keithley representatives in most countries maintain service
and calibration facilities.

To insure prompt repair or recalibration service, .please contact
your local field representative or Keithley headquarters directly
before returning the instrument. Estimates for repairs, normal
recalibrations and calibrations traceable to the National Bureau of
Standards are available upon request.

KEITHLEY
The measurement engineers.

Keithley Instruments, Inc., 28775 Aurora Road, Cleveland, Ohio 441 39. (216) 248-0400
European Headquarters: Heiglhofstrasse 5, 0-8000 Munchen 70 West Germany, (089)7144065
United Kingdom: 1 Boulton Road, Reading, Berkshire. (0734) 861287
France: 44 Rue Anatole France, F-91121 Palaiseau (01) 014-22-06
I N S T R U C T I O N MANUAL

M o d e l 725

Cur rent Sou r c e

COPYRIGHT 1 9 7 8 , KEITHLEY INSTRUMENTS, INC.
F I R S T PRINTING, A P R I L 1 9 7 8 , CLEVELANDy OHIO U. S . A.
DOCUMENT NO. 2 9 6 3 1 , R E V I S I O N CODE A A
INSTRUCTION MANUAL
Programmable Current Source
Model 725

WARN I NG

I f c u r r e n t i s programmed t o 0 and u n i t i s i n o p e r a t e , a COMPLIANCE VOLTAGE up t o 125
v o l t s may be p r e s e n t a t t h e o u t p u t t e r m i n a l s . For maximum o p e r a t o r s a f e t y t h e Model 7 2 5
C u r r e n t Source s h o u l d always b e s e t t o STANDBY mode when no c u r r e n t o u t p u t i s needed.
The u n i t s h o u l d a l s o b e s e t t o STANDBY p r i o r t o c h a n g i n g r a n g e o r p o l a r i t y . This w i l l
e n s u r e t h a t no t r a n s i e n t c u r r e n t s w i l l b e g e n e r a t e d .

WARN I NG

T h i s i n s t r u m e n t i s n o t a p p r o v e d f o r use i n "hazardous l o c a t i o n s " as d e f i n e d i n t h e
N a t i o n a l E l e c t r i c a l Code, C l a s s e s 1 , 1 1 , and I l l .

Class'l: Those l o c a t i o n s i n w h i c h f l a m m a b l e gases o r v a p o r s a r e o r may be p r e s e n t i n
the a i r i n q u a n t i t i e s s u f f i c i e n t t o produce e x p l o s i v e o r i g n i t a b l e m i x t u r e s .
Class 1 1 : Those l o c a t i o n s t h a t a r e hazardous because o f t h e p r e s e n c e o f c o m b u s t i b l e
dust.
Class I l l : Those l o c a t i o n s t h a t a r e hazardous because o f t h e p r e s e n c e o f e a s i l y i g n i t a b l e ~

fibers or flyings.
INSTRUCTION MANUAL
Programmable Current Source
Model 725

CONTENTS

Sect i o n Page

CONTENTS .................... . . . . . . . . . . . . . . . ...
iv
I I I
ILLUSTRATIONS
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1 . GENERAL D E S C R I P T I O N
1-1. GENERAL 1-1
1-2. WARRANTY INFORMATION
1-3. CHANGE NOTICE
......................... 1-1
1-1
2. OPERATION .................................. 2-1
2-1.
2-2.
2-3.
GENERAL
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-111
CONTROLS
I NDI CATORS 2-
2-

2-4. C O N N E C T I O N S . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
2-5. REMOTE PROGRAMMING AND CONTROL 2-6
2-6. MEASUREMENT CONSIDERATIONS
2-7. PRELIMINARY PROCEDURES
...................... 2-8
2-9
.......................
2-8. OPERATING C H A R A C T E R I S T I C S
3. C I R C U I T D E S C R I P T I O N
2-11
3- 1
3-1. G E N E R A L . ,
3-2. THEORY OF OPERATION
.............................. 3-1
3- 1
.
3-3. C I R C U I T R Y
3-4. S W I T C H I N G
............................... 3-1
3-3
r
..........
4. A C C E S S O R I E S . . . . . . . . . . . . . . . . . . . . . . .
4-1. GENERAL
4-1
4- 1
5. MAINTENANCE
5-1. GENERAL
................................. 5-1
5- 1
..........................
5-2. S E R V I C I N G SCHEDULE
5-3. PARTS REPLACEMENT
5-1
5- 1
..............................
5-4. C A L I B R A T I O N
5-5. TROUBLESHOOTING
5-1
5- 1
6. C A L I B R A T I O N
6-1. GENERAL
................................. 6-1
6- 1
6-2. T E S T EQUIPMENT ............................
6-3. C A L I B R A T I O N PROCEDURES
6-1
6- 1
7. REPLACEABLE PARTS
7-1. GENERAL
.............................. 7-1
7- 1
7-2. ORDERING INFORMATION
7-3. FACTORY S E R V I C E
......................... 7-1
7- 1
...................
7-4. CROSS REFERENCE OF MANUFACTURERS
7-5. COMPONENT LAYOUTS
7-1
7- 1
7-6. SCHEMATICS .............................. 7-1

AA iii
INSTRUCTION MANUAL
Programmable Current Source
Model 725

I LLUSTRAT IONS

F i g u r e No. Title Page

1-1 . . ..
Model 725 Programmable C u r r e n t Source...... 1-1
2- 1
2- 1
2-2 ...... ..
Model 725 F r o n t Panel
Model 725 Rear Panel .. ..... 2-2

...................
2-3 Schematic o f O u t p u t Connections 2-3
2-4 T r i a x i a l Connector Schematic 2-3
2-10
2-5
2-6 ..........................
R e s i s t i v e Load
F l o a t i n g Supply 2-1 1

...................
2-7 Capac i t i ve Load 2-12
2-8 Voltage L i m i t C h a r a c t e r i s t i c s 2-12
3- 1
4- 1
6- 1
Model 725 B l o c k Diagram
.............. . . ..
Model 1004 Rack Mounting K i t
-
3- 1
4- 1
6-0
6-2
Chassis
AccuracyCheck ..................... . . . . .
Top View

R e g u l a t i o n Check
6-5
6-6
6-3
6-4 .............
C u r r e n t Model Vs. V o l t a g e Mode Waveforms 6-6
7- 1
7-2
Component Layout, PC-22%
Component Layout, PC-438
-
.... .......... .... 7-10
7-1 1
7-3
7-4
Schematic Diagram
Schematic Diagram - ...........
Model 725 A m p l i f i e r
Model 725 Power Supply
7-12
7-13
INSTRUCTION MANUAL GENERAL DESCRIPTION
Programmable Current Source
Model 725

r
SECTION 1 . GENERAL DESCRIPTION.

1-1. GENERAL. The Model 7 2 5 i s a c o m p l e t e l y programmable c u r r e n t s o u r c e . Ranges a r e
programmed b y a BCD code. The m a g n i t u d e o f t h e c u r r e n t ( a s a % of f u l l s c a l e ) i s pro-
grammed b y use o f a Kepco S N - 3 D i g i t a l - t o - A n a l o g C o n v e r t e r o r e q u i v a l e n t . Specifications
f o r t h e Model 7 2 5 a r e g i v e n i n T a b l e 1 - 1 .

1-2. WARRANTY INFORMATION. The w a r r a n t y i s s t a t e d on t h e i n s i d e f r o n t c o v e r o f t h e
manual.

1-3. CHANGE NOTICE. Improvements o r changes t o t h e i n s t r u m e n t n o t i n c o r p o r a t e d i n t o t h e
manual w i l l b e e x p l a i n e d on a Change N o t i c e Sheet a t t a c h e d t o t h e i n s i d e back c o v e r .

IMPORTANT
The A symbol can b e f o u n d i n v a r i o u s p l a c e s i n t h i s I n s t r u c t i o n Manual. Carefully
r e a d t h e a s s o c i a t e d CAUTION s t a t e m e n t s w i t h r e g a r d t o p r o p e r use and h a n d l i n g o f
the instrument. Damage t o t h e i n s t r u m e n t may o c c u r i f t h e s e p r e c a u t i o n s a r e i g n o r e d .

Thet symbol can b e f o u n d i n v a r i o u s p l a c e s i n t h e I n s t r u c t i o n Manual. T h i s
symbol i n d i c a t e s t h o s e a r e a s o n t h e i n s t r u m e n t w h i c h a r e p o t e n t i a l shock h a z a r d s .
C a r e f u l l y r e a d t h e a s s o c i a t e d W A R N I N G s t a t e m e n t s w i t h r e g a r d t o p r o p e r use and
h a n d l i n g o f t h e i n s t r u m e n t . S e r i o u s p e r s o n a l i n j u r y may r e s u l t i f t h e s e p r e c a u t i o n s
a r e ignored.

FIGURE 1-1. Model 7 2 5 Programmable C u r r e n t Source.

AA 1-1
GENERAL DESCRIPTION INSTRUCTION MANUAL
Programmable Current Source
Model 725

TABLE 1 - 1 .
SPECIFICATIONS
Model 7 2 5 P r o g r a m m a b l e C u r r e n t S o u r c e

GENERAL: The Model 725 p r o v i d e s c o n s t a n t PROGRAMMING:
c u r r e n t under program c o n t r o l .
Functions: Range, p o l a r i t y , s e l e c t i o n o f
Range, p o l a r i t y , o p e r a t e / s t a n d b y
1 o f 4 c o m p l i a n c e l i m i t s , and
and s e l e c t i o n o f compliance l i m i l
operate/standby are a l l d i r -
a r e a l l d i r e c t l y programmable.
e c t l y programmable. Magnitude
M a g n i t u d e i s programmed b y u s e o f
i s programmed b y a 0-IOV s i g -
a Kepco SN-3 D i g i t a l t o A n a l o g
n a l f o r 0-100% o f f u l l r a n g e .
C o n v e r t e r or e q u i v a l e n t .
Compatible Logic: TTL o r DTL. Maximum i n p u t
OUTPUT: (when u s e d w i t h Kepco Model SN-3) l o a d , 10 TTL l o a d s , e x c e p t
DC C u r r e n t : IOOnA t o IOOmA f u l l s c a l e i n o p e r a t e / s t a n d b y where d r i v i n g
seven decade ranges. c i r c u i t m u s t s i n k 60mA.
Voltage: F o u r d i g i t a l l y s e l e c t a b l e comp- L o g i c Power: An e x t e r n a l 5 V ( t 0 . 2 5 V ) @
l i a n c e l i m i t s a r e v a r i a b l e be- 250mA T T L - c o m p a t i b l e l o g i c
tween 12 v o l t s and 90 v o l t s . With supply i s required.
no c o m p l i a n c e l i m i t programmed, ISOLATION: 1090hms; d i g i t a l l o w t o o u t p u t
constant current i s maintained t o
low.
a t l e a s t 100 v o l t s .
ENVIRONMENT: 20" t o 30