Text preview for : 227D(Model227_252C2271).pdf part of Keithley 227D(Model227 252C2271) Keithley 227 227D(Model227_252C2271).pdf



Back to : 227D(Model227_252C2271).p | Home

Test Instrumentation Group
Keithley Instruments, Inc.
28755 Aurora Road
Cleveland,Ohio 44139-1891
(216)X3-0400 . Fax: (216)498-2704
1-800-552-1115




INSTRUCTION MANUAL

MODEL 227


CURRENTSOURCE
(AND MODEL 2271 PROGRAMMING OPTION)
INSTRUCTIONMAMlAL
Model 227


(and Model 2271 Programing Optionj




OCOPYEICHT 1976, KEITHLEY INSTRUMENTS,
INC.
FOURTHPRINTING, JAN. 1978, CLE"!%LAND,
OHIO, U.S.A.
MODEL227




WARNING
EXTREME CARESHOULD TAILFNTO AVOID
BE
CONTACT WITR RIGH VOLTAGES WREN MAKING
CONNECTIONS EXTh?2NAL
n, TERMIIULS OR
WREN SERVICING TRE MODEL227 WITX TOP
AND BOTT(3.lCOVERSRZMOVEV.
RecommendedProcedures for User Safety:



2. Make certain third-wire ground pin an line power card ls connected fo earth ground.
This will ensure that the Model 227 chassis is at ground potential.

3. Before making connections anywhere on the front or rear panels, remove power to
Model 227 by detaching the line power cord, or by setting the power switch to OFF,
or by setting the OUTPUTSELECTOR switch to "SHORT" or "OPEN". Also, remove all
external power Sources which may be connected between LO and CASE.

4. If the Model 227 LO terminal is to be floated above CASE, make certain that the
metal link is removed between front panel LO and CASE terminals.
5. Make certain cable connections are well insulated and that no bare wires are ex-
posed. Use connectors with fully enclosed and insulated virinS.
6. During calibration with top and/or bottom covers removed, extreme care must be
taken to avoid contact with exposed circuitry. Use insulated tools and gloves for
maximm safety. Various test points and adjustment circuitry my be up to 300
volts potential.




iii
0975
CONTENTS MODEL227



CONTENTS



SECTION PAGE

SPECIFICATIONS __-__-_----_-_____________________ vi

1. GE- I&?,,mTION __-----_________-____________ 1

2. INITIAI. PREPARATION
__--------___------_--- 2
3. ,,PE&Q-ING INS'fRUCTIONS--________-__-______----- 8
4. *CcESSlJRIES _----__---_-__-_____---------------- 24
5. THEORY OPEP\ATION
OF __--________________----------- 25
6. MAINTEN)JCE ---_--___---__-_____---------------- 27
7. REPmCE&,LE PARTS__-______--___-___-____I___ 39
SYNDICS --__--------_____------------------------ 60




iv 0975
MODEL227



ILLUSTRATIONS



Fig. No. Title Page

1 FrQ"f panel. ____________-__-__--______I_____________----- 1
2 Rear Panel Showing Line Switches. --------------------------- 2
3 RecommendedMounting and Ventilation. ------------------------ 3
4 LQc*tiQ" of *ir Filter. ------------------------------------- 3
5 Voltage Levels Present at Front and Rear Panel Terminals. ------ 5
6 Front Panel Terminals and Controls. ---------------__-_--------- 7
7 Rear p**e1 Terminals. -------------------------------------- 7
8a.b.c Output Selector Switch Positions. ------------------------------ 9
9 Voltage Output Versus % Rotation for Compliance Control. ------- 10
10 Connections as a Current Source with Resistive Load. ---------- 11
11 Connectians es a Current Sink wirh Resistive Load. ------------ 11
12 Connections as a Current Source with Capacitive Load. ---------- 13
13 Connecrfo"s as a Currenr Source with Inductive Load. ---------- 13
14a,b Power Limits when used as a Current Sink. --------------------- 14
15 Typical Output Impedance Versus Frequency for lOOOvA Range. ---- 15
16 Output Noise Versus Compliance Voltage. --------------------- 16
17 Output Noise Versus RC Time Conetant of External Load. ------- 16
18 Connections for Floating Operation. --------------------------- 17
19 Frequency Response for Voltage Programming. ------------------- 18
20 Use of Voltage Program Inpur to Modulate Current. -------------- 18
21 Rear panel Remote Progrenrming Connector. -------------------- 20
22 Compliance Progranrming up to 5OV. ---------------------------- 21
23 Compliance Programming up to 3OOV. ---------------------------- 21
24 Resistance Programming of Current. --------------------------- 22
25 Preferred Cabling Te.=,,"iques. __-______________--------------- 23
26 Model 1008 Single Rack Mounting Kit. ------------------------ 24
27 Overall Block Diagram of Model 227. ---------------------------- 26
28 Simplified Diagram of Current Source. ------------------------- 27
29 Test Set-up for Model 22712271 Calibration. ------------------- 36
30 Location of Adjustments with Top Cover Removed. --------------- 38
31 Location of Adjustments with Bottom Cover Removed. ------------- 38
32 Chassis Assembly. ---------_______________________________----- 41
33 Compo"e"t Layout, PC-330. ------------____-____________________ 53
34 component Layout, PC-331. ----------------------------------- 55
35 Component Layout, PC-342. ------------_-______________________ 56
36 Case Outlines, Integrated Circuits. ---------_--_-----_----- 57
37 Case Outlines, Integrated Circuits. ------------------------- 58
38 Case Ourlines, Transistors. __-_-------__-------____________ 59




0975
SPECIFICATIONS MODELZL,



SPECIFICATIONS



Calibrated et 25'C " 3*C

AS A DC CONSTANT CURRSNT SOURCE GENERAL
OUTPUT: STABILITY: C(O.O05% of Betting + 0.005% of =ange)/Y
current : ?l microampere (1000 microamperes full Short-tefm stability up to 30 days is masked by thi
range) to tlOO0 milliamperes in four decade temperature coefficient.
ranges; 3-digit in-line readout; 11% overrange LOADR!.?GULATION: t0.005% of range from no load to
to 1110. full load.
Voltage Compliance: *300 volts on 100 milliampere LINE REGULATION: +O.OOS% range for 10% change in
of
range and lauer. f50 volts on 1000 milliampere line voltage.
range. Compliance limit continuously adjustable NOISE: Wideband noise less than (0.03% of range + 2
from appraximately 3 volts t0 full voltage cam- millivolts) ~llls above 5 Hz.
plialXe.
Floating: 1500 volts maximum off chassis ground.
RESOLUTION: 0.005% af range, 3-digit readout. ENVIRONMENT:
ACCURACY: ?(0.5% of Betting + 0.12% of range). operating: O'C to 50