HP 7414A Service manual

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OPERATING AND SERVICE MANUAL
THERMAL-TIP
RECORDER
7414A
HEWLETT i:I PACKARD

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",MANUAL CHANGES
MODEL 7414A
THERMAL-TIP RECORDER
(MANUAL TITLE)
MANUAL SE RIA LS PRE FI XED _----"1"-"1'-'4""'5~A~ _
MANUAL PRINTED MARCH, 1972
MAKE ALL CHANGES IN THIS MANUAL ACCORDING TO THE ERRATA BELOW. ALSO CHECK THE FOLLOWING TABLE FOR
YOUR INSTRUMENT SERIAL PREFIX (FIRST THREE DIGITS OF AN EIGHT DIGIT SERIAL NUMBER) AND MAKE ANY LISTED
CHANGE(S) IN THE MANUAL.
SERIAL PREFIX
MAKE MANUAL CHANGES
SERIAL PREFIX MAKE MANUAL CHANGES
ALL INSTRUMENTS
ERRATA
1 ?O?A
f"'l-lANr.E 1
1207A
CHANGE 2
ERRATA
Page 5-4, Paragraph 5-15,
Step g:
Page 5-5, D, 3, Step c:
Page 5-10, Step a(4):
Page 5-23, Paragraph 5-47,
Step g:
Page 5-25, Figure 5-14:
Page 6-6, Table 6-1:
Page 6-12, Table 6-1:
Page 6-14, Table 6-1:
Page 6-16, Table 6-1:
Change reference to Paragraph 5-57 to Paragraph 5-59.
Change Figure 6-15 reference to Figure 5-4.
Should read " ... by levering from front of top bar ... "
Change step to read "Remove snap ring holding sprocket
to drive roller shaft using snap ring pliers. "
C-ring 0510-1017 shown has been changed to snap-ring
0510-1012, which must be removed with snap-ring pliers.
Add on A3MP1, 7124-1605, Label 59-61 (Hz).
Change A3J6, receptacle to 1251-2995, and A3J5 to 9100-3198.
Change A9T1 to 07754-60470.
After A10MP5, add attaching part 0510-1012; Ring, retaining.
A10A1MP26 was changed in error; see Change 1.
Add to Option 008, 7124-1604, Label 49-51 (Hz).
March, 1972
DATE
PUB. 100-1
07414-91999
MANUAL PART NUMBER
A
SUPPLEMENT

CHANGE 1:
CHANGE 2:
MANUAL CHANGES,
MODEL 7414A (Cont'd)
Page 6-14, Table 6-1:
On A10A1MP26, Add 07754-00880 Spring, Solenoid Adjustment;
Delete (1) 07754-00840 Spacer and (3) 07754-00860 Shim.
Page 6-13, Table 6-1:
Delete A10W1, Cable, interlock.
Page 6-27, Figure 6-12:
Delete INTERLOCK ASSEMBLY at bottom center of schematic;
Substitute a black jumper across the pins on the Transfer Board A3A1.
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0-18937-4
0-18930-6
March, 1972
- 2 - A
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~MANUAL CHANGES
MODEL 7414A
THERMAL-TIP RECORDER
(MANUAL TITLE)
MAN UA L SE RIA LS PR EFI XED -=1=1c...:.
4
.L.5.:..:A:....- _
MANUAL PRINTED MARCH, 1972
MAKE ALL CHANGES IN THIS MANUAL ACCORDING TO THE ERRATA BELOW. ALSO CHECK THE FOLLOWING TABLE FOR
YOUR INSTRUMENT SERIAL PREFIX (FIRST THREE DIGITS OF AN EIGHT DIGIT SERIAL NUMBER) AND MAKE ANY LISTED
CHANGE IS) IN THE MANUAL.
SERIAL PREFIX
ALL INSTRUMENTS
!'.!. NEW OR REVISED ITEM
.6 ERRATA
MAKE MANUAL CHANGES
ERRATA
SERIAL PREFIX
MAKE MANUAL CHANGES
Page 5-22, Figure 5-12: On Speed Control Connections, Pin 3 connects to
ORANGE wire and Pin 4 connects to YELLOW wire.
Page 5-28, Figure 5-18: In lower right corner, specification for SHAFT END
PLAY of gearbox should be 0.007 inch (0.018 rmn).
April, 1972
DATE
PUB. 100-1
07414-91999
MANUAL PART NUMBER
B
SUPPLEMENT

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07414·1
HEWLETT ~ PACKARD
MODEL
7414A
THERMAL-TIP
RECORDER
SERIALS PREFIXED: 1145A
This manual applies directly to HP Model 7414A
Thermal Tip Recorders having serial numbers pre-
fIxed 1145A.
OTHER PREFIXES:
For instruments having prefixes lower than 1145A,
refer to Appendix I, Backdating Supplement. For
higher prefixes,
see the manual change sheets pro-
vided.
OPERATING AND SERVICE MANUAL
0741 4-91999
Copright 1972
Hewlett-Packard
Medical Electronics Division
175 Wyman Street
Waltham, Massachusetts 02154
PRINTED, MARCH 1972
/

Table of Contents
TABLE OF CONTENTS
Model 7414A
Paragraph
Page Paragraph Page
SECTION I, GENERAL INFORMATION 1-1
4-35. Paper Feed 4-9
I-I.
Introduction 1-1 4-37. Recorder Power Supply and
1-3. Four-Channel Recorder
1-1 Regulator Circuits 4-9
1-9. Applications and Specifications
1-1
4-39. Recorder
DC Power Supplies 4-9
1-13. Accessories
1-1
4-41. Regulator/Oscillator .4-11
4-49. Marker Circuits .4-11
SECTION II, INSTALLATION 2-1
4-54. 440 Hz Oscillator
.4-12
2-1. Initial Inspection
2-1
4-57. 2400
Hz Oscillator .4-12
2-3. Mechanical Check 2-1
2-5. Performance Tests 2-1 SECTION V, MAINTENANCE
5-1
2-7. Damage Claims 2-1
5-1. Introduction
5-1
2-9. Storage
2-1
5-3. Test Equipment and Lubricants
5-1
l"
2-11. Installation 2-1
5-5. Performance Checks
5-1
2-13. Preamplifier Installation 2-1
5-8. Variable Line Voltage
5-2
2-15. Power Connections 2-1
5-10. Preventive Maintenance 5-2
2-18 Signal Connections
2-1
5-12. Operational Checks and Inspection 5-2
2-22. Tape System Connections 2-2 5-16. Cleaning 5-9
2-24. Remote Control and Marker Connections 2-2 5-18. Lubrication
5-9
5-20. Electrical Checks
.5-10
SECTION III, OPERATION 3-1 5-22. Adjustments and Minor Repairs
.5-10
3-1. Introduction
3-1 5-24. Paper Drive Adjustments
.5-10
3-3. Control Locations 3-1
5-29. Stylus Adjustments
.5-12
3-5. System Operation
3-1
5-38. Corrective Maintenance .5-18
5-40. Galvanometer Removal
SECTION IV, PRINCIPLES OF OPERATION
4-1
and Replacement .5-19
4-1. Introduction
4-1 5-43. Drive Unit Removal and Replacement .5-21
4-4. Preamplifier Power Supply Circuits
4-1
5-46. Paper Table Disassembly for Drive
4-7. Recorder Signal Circuits
4-1
Roller Replacement
.5-23
4-11. Stylus Linkage
4-1
5-48. Gearbox Removal and Overhaul
.5-23
4-13. Galvanometer Position Feedback
4-1 5-55. Solenoid Adjustment
.5-34
4-17. Galvanometer Damping 4-2 5-58. Marker Assembly Maintenance ·5-34 I
4-20. Heat Control Circuit 4-2
4-22. Power Control Circuits 4-2 SECTION
VI, RECPLACEABLE PARTS 6-1
4-26. Chart Drive 4-7 6-1. Introduction 6-1
4-28. Chart Motor 4-7 6-4. Reference Designations 6-1
4-30. Speed Control 4-7 6-9. Ordering Information 6-2
LIST OF ILLUSTRATIONS
Figure Page Figure
Page
I-I.
Model 7414A Recording System 2-5. Tape System Connections Using Control
and Optional Configurations 1-0 Sections 4681A and 4682A 2-6
1-2. 8800 Series Preamplifiers
1-3
2-6. Remote Control and Marker Connections 2-7
2-7. Option 001 Rack Mounting Kit
2-8
2-1. Recorder Access for Receiving Inspection 2-2
2-2. Recorder Rear Panel Connections and Fuse 3-1. 7414A Recording System, Control
Locations.
2-3 Locations 3-2
2-3. Recorder and Mobile Cart Power 3-2. Paper Loading Procedure 3-3
Connections 2-4
2-4. 7414A System
Input Cable Preparation 2-5 4-1. Model 7754A Recorder, Block Diagram 4-0
07414-1

Model 7414A
Table of Contents
LIST OF ILLUSTRATIONS (continued)
Figure
Page
Figure
Page
.6-22
.6-23
.6-24
.6-25
.5-32
.5-33
.5-33
.5-34
.6-3
Model 7754A Recorder
(End Itern)
Unit Housing
Al (07754-60270), Parts
Location Diagram
..... .6-19
Control Panel A2
(07754-60240) Subassemblies,
Parts Location Diagram .6-19
Control Panel A2 Schematic Diagram .6-20
6-4.
6-1.
6-2.
6-3.
5-22. Overriding Clutch Lubrication
(Secondary Shaft)
5-23. Gearbox Shaft
End Play Adjustment
5-24. Gearbox
Input Chain Tension
Adjustment
.....
5-25. Marker Assembly Adjustment and
Removal .
6-5. Control Switch Board A2A1(07754-60120),
Component Location
Diagram. . . . . 6-21
6-6. Heat
Potentiometer Board A2A2 (07754-60130),
Component Location Diagram . .. .6-21
6-7. Preamplifier Power Supply Board A2A3
(07754-60140)
Component Location
6-8. Power Supply A3 (07754-60050)
Subassemblies, Attachments
6-9. Power Supply A3, Parts Location Diagram
6-10. Power Supply A3, Schematic Diagram
(Less A3A1) .
6-11. Transfer Board
A3Al (07754-60150),
Component Location Diagram ... 6-26
6-12. Transfer Board
A3Al, Schematic Diagram .. 6-27
6-13. Driver Amplifier A4, A5, A6, A7 (07754-60170)
Component Location Diagram. . . . . 6-28
6-14. Driver Amplifier A4, A5, A6, A7;
Schematic Diagram 6-29
6-15. Regulator/Oscillator A8
(60 Hz, 07754-60180),
or A9 (50 Hz, 07754-60181), Component
Location Diagram and Schematic. . . . 6-30
6-16. Drive Unit
AI0 (07754-60250) Subassemblies,
Parts Location Diagram 6-31
6-17. Gearbox
AI0Al (07754-60040), Parts Location
Diagrams . . . . . . . . . . . . . 6-32
6-18. Galvanometer
All, A12, A13, A14
(07754-60070), Parts Location Diagram .6-33
6-19. Marker A15, A16
(07754-60350), Parts Location
Diagram . . . . . . . .
.. .6-34
6-20. Oscillator,
2400 Hz A17 (868-500ACI3) .6-34
6-21. Oscillator,
440 Hz A18 (868-500ACI4) .6-35
6-22. Accessories, A19 (Reference) .... .6-35
·5-13
·5-14
·5-15
4-3
4-6
4-7
4-8
4-9
4-4
4-5
4-5
·5-12
·5-3
·
5-11
·5-16
·5-18
·5-31
.4-10
4-12
·4-12
.5-19
.5-20
.5-21
.5-22
.5-24
.5-25
.5-26
.5-27
.5-28
.5-28
.5-29
.5-29
5-1. Test and Adjustment Points
5-2. Test Cable, Plug and Fixtures
5-3. Driver Amplifier and Regulator/
Oscillator Test
....
~2. Preamplifier Power Supply Circuits,
Simplified Diagram
4-3. Recorder Signal Circuits, Simplified
Diagram .
~4. Galvanometer Position Feedback
Circuit .
4-5. Galvanometer Damping
4-6. Recorder Power
Control Circuits,
Simplified Diagram
4-7. Chart Drive Gears
4-8. Gearbox Power Flow
4-9. Paper Feed Path
4-10. Recorder Power Supply and Regulator
Circuits, Simplified Circuit
4-11.
440 Hz Oscillator Circuit
4-12. 2400 Hz Oscillator Circuit
5-4. Regulator/Oscillator Board Test
Points ........
5-5. Driver Amplifier Board Test Points
5-6. Recorder Lubrication Points
5-7. Paper Brake Felt Cover Removal and
Replacement
....
5-8. Stylus Adjustments . . . .
5-9. Channel Time Synchronization
Adjustment
....
5-10. Stylus Removal and Replacement
5-11. Stylus Lapping Procedure
5-12. Drive Unit Removal .....
5-13. Paper Table Removal
....
5-14. Drive Roller and Table Link Removal
(Part 1) .
5-15. Drive Roller
and Table Link Removal
(Part 2)
5-16. Gearbox Removal .
5-1 7. Drive Chain Removal .
5-18. Gearbox Inspection and Solenoid Adjustment
5-19. Gearbox Cover Removal
5-20. Gearbox
Shaft Removal
5-21. Spring Clutch Lubrication
(Primary Shaft)
LIST OF TABLES
Table
1-1. Model 7424A Recording System
Specifications
(7754A Recorder)
1-2. Model
7414A Recording System,
Equipment Options
5-1. Recommended
Test Equipment
5-2. Lubricants and Solvents Required
Page
1-2
1-3
5-1
5-2
Table
5-3. Electrical Performance Checks and
Adjustments
54. Paper Drive Troubleshooting
6-1. Replaceable Parts
6-2. Code List
of Manufacturers
Page
. 54
. .5-15
.6-3
.6-18
07414-1
jj

Section I
General Information
1-0
Model 7414A
MODEL 7414A RECORDER IN
BENCHTOPENCLOSURE
MOBI LE CART OPTION 054
Figure 1-1. Model 7414A Recording System and Optional Configurations
07414-1

Model 7414A
SECTION I
GENERAL
INFORMATION
Section I
General Information
1-1. INTRODUCTION.
1-2. This manual contains installation, operating, and main-
tenance instructions for
your Hewlett-Packard Model
7414A Recording System, which has four channels, and
produces four recorded traces with heated styli on heat-
sensitive chart paper Permapaper.® Other manuals, for use
with the 8800-Series Preamplifiers, and for
other equip-
ment ordered with the 7414A System are provided sepa-
rately since avariety
of preamplifiers, scopes, tape re-
corders, computer terminals and control units may be used
with the recording system.
1-3. FOUR-CHANNEL RECORDER.
1-4. The Model 7414A Recorder (Figure 1-1) at the core
of the system, is supplied mounted in a benchtop enclosure.
It is optionally available mounted in amobile cart, or
unenclosed, for mounting in an existing
equipment rack.
1-5. The Recorder houses
up to four Hewlett-Packard 8800
Series Preamplifiers and supplies them with operating
power and signal connections. The preamplifiers, selected
for each channel and ordered separately, are installed and
tested with the recorder
at the factory. It is easy to change
the function
of any channel by loosening two front panel
thumbscrews and replacing the preamplifier with adifferent
model.
1-6. The Model
7414A Recording System records signals
monitored from devices, processes, or transducers. To
monitor asignal, connect the signal cable to the input
connector for the assigned channel on the recorder rear
panel. The rear panel inputs are connected
to signal condi-
tioning preamplifiers
mounted in the recorder. Each pre-
amplifier
output is applied to apower amplifier that drives
one recording stylus.
From the preamplifier output on, all
four channels are identical.
For ease of maintenance, all
electrical adjustments are accessible from the front or top
of the recorder, and most assemblies can be removed with
the recorder
mounted in the enclosure, mobile cart, or
equipment rack.
1-7. The recorder uses Z-fold chart paper for convenient
access to any
part of the recording. The folded paper
permits rapid scanning
of the record to assess response
trends. All pages are numbered to allow insertion in a
notebook, or the complete record may be filed in the
original flat
box (pages are 8 x 12 inches, 20 x 30 cm,
approximately). Anew pack
of chart paper can be loaded
quickly, in less
than ten seconds, to minimize loss of
recording continuity.
07414-1
1-8. The recorder may be remotely controlled to mark
events, start, or go on standby. Two event markers are
provided; one permits the user to indicate the start and
finish
of an event, the second provides time interval
marking in minutes
or seconds.
1-9. Applications and Specifications.
1-10. Awide selection of transducers and Hewlett-Packard
preamplifiers are available for research, laboratory, and
industrial applications. The following list gives some typical
applications where data can be measured, monitored, and
recorded using the recorder and Hewlett-Packard preampli-
fiers:
Engine Testing
Aircraft, Missile, and Space Flight Analysis
Seismographic Studies
Environmental Pollution Monitoring
Telemetry Systems
Production Control
Relative Displacement and Velocity Monitoring
1-11. Hewlett-Packard will be glad
to cooperate in the
selection
of transducers and preamplifiers for any particular
measurement, and to send you information
as additional
instruments are developed
to provide your recording system
with
other capabilities. For help in expanding your system,
contact the field engineer
at any Hewlett-Packard Sales/
Service Office listed in the
back of this manual.
1-12. Table
1-1 gives the specifications for the Model
7754A Recorder, a
part of the Model 7414A Thermal Tip
Recording System, and Table
1-2 lists the recorder options
available. Preamplifier specifications will be found in the
separate preamplifier manuals. Preamplifier frequency
response and rise time
must be modified by the frequency
response and rise time specifications given for the recorder.
Recording quality
is improved by the recorder's low level of
hysteresis distortion. Minor waveform details are not
obscured by recorder-contributed distortion.
1-13. 8800 Series Preamplifiers (7414A System).
1-14. The 7414A Recording System is factory assembled
for use with the solid-state
8800 Series Preamplifiers
(Figure 1-2). They plug in interchangeably from the front
of the recorder. Signal connections are made at the rear,
but signals can be monitored from the front of the
preamplifiers. The general characteristics
of each preampli-
fier are given in the following paragraphs.
For complete
information see the preamplifier instruction manual.
1-1

Section I
General Information
Table 1-1. Model 7414A Recording System Specifications (7754A Recorder)
Model 7414A
1-2
SENSITIVITY: ±2.5 volts (±0.5 volts) full scale.
(Adjustable.)
FREQUENCY RESPONSE: Flat within ±0.5 dB
(±6%), dc to 50 Hz, reference 50 div. at 10 Hz; down
less than 3 dB at 100 Hz, reference 10 div. at 10 Hz.
POWER RESPONSE: At 50 Hz: More than 50 divi-
sions (full scale). At 100 Hz: More than 10 divisions.
CHART SPEEDS: 0.25,0.5,1.0,2.5,10,25,50, and
100 mm/sec. Speed Regulation:
±1 %. Paper Weave:
Less than 0.5 mm. (Speeds selected via panel push-
buttons.)
INPUT IMPEDANCE: Loading at preamplifier out-
put is 50 kilohms, min.
NOISE: Not discernible with recorder input open or
shorted.
GAIN STABILITY: (One hour warmup). Tempera-
ture: 0.25 div/25°C, from 20°C to 40°C. Line Volt-
age: 0.25 divisions from 103 to 127 vac.
ZERO DRIFT: (One hour warmup, input shorted).
Temperature: 0.25 div/25°C, from 20°C to 40°C.
Line Voltage: 0.25 divisions from 103
to 127 vac.
OUTPUT LINEARITY: Error less than ±0.25 divi-
sions at any scale point, including hysteresis (after
calibration at center scale and at +20 divisions).
With 8808A Log-Audio Preamplifier, error
less than
0.5 division at any scale point, including hysteresis
(after calibration for zero error at upper and lower
scale ends).
RISE TIME: 5milliseconds over any 20 divisions
(10% to 90%), overshoot adjusted for
4% or less.
LIMITING: Stylus limit 1.5 mm over channel edge
(adjustable).
MARKERS: Event: Local or remote control (mono-
polar), located on right side, between channels 3and
4. Timed: 1minute or 1second interval (monopolar),
located on left side, between channels 1and 2.
HYSTER ES IS: Less than ±0.15 divisions (see line-
arity).
DAMPING: Galvanometer damping set to about 4%
overshoot.
CHART PAPER: Four 40 mm wide channels, each
with 50 divisions; time lines every 1mm; heat
sensitive Z-fold Permapaper ®with green grid lines is
available in packs of 500 sheets, each sheet 12 inches
(30 cm) long, and numbered for footage and index-
ing.
Green grid lines and black stylus trace make recording
suitable for reproduction.
PAPER LOADING: No threading required. Loading
in 10 seconds.
PAPE R TAKE UP: On shelf of recorder, or in drawer
provided with cart installations.
TRACE WIDTH: 0.020 inches (0.5 mm) nominal;
depends upon heat control setting.
REMOTE OPERATION: Rear panel connector J8:
Remote operation
of chart drive, event marker,
optional extra marker. Connector also supplies ±12,
±20, and -24 vdc.
FRONT PANEL CONTROLS: Power, Chart Drive,
Chart Speed selection, Time Marker, Event Marker,
Channel Heat controls.
OTHER CONTROLS: Each Channel: Position, Gain,
Damping, High Limit, Low Limit,
440 Hz Oscillator
Amplitude.
POWER REQUIRED: 115/230 volts ac, (±10%), 60
Hz (50 Hz optional), 300 watts. Warmup time, ap-
proximately 15 seconds.
DIMENSIONS: Height: 10.5 inches (29 cm). Width:
19.0 inches (48.3 cm), for standard rack. Depth:
22.75 inches (57.3 cm). Projection: 2.5 inches (6.3
cm) from rack front.
Bench Top Enclosure: Height: 11.87 inches (30.2
cm). Width: 20.25 inches (51 cm). Depth: 24 inches
(60.5 cm). Paper Takeup Tray projects 10.5 inches
(26.4 cm) from front; hangs down 5.5 inches (13.8
cm).
Mobile Cart (Option 054): Height: 41 inches (105
cm). Width: 23 inches (59 cm). Depth:
31 inches (79
cm).
WEIGHT: Recorder: 76 Ibs (34.4 kg). Bench Top
Enclosure:
94 Ibs (42.5 kg); with paper takeup shelf
95.5 Ibs (43.3 kg); with Mobile Cart: 1911bs (81 kg).
ENVIRONMENT: Maximum ambient temperature
(free air circulation): 40°C (104°F). No free air
cir~ulation: 25°C (77°F). Location: Free from dust,
explosive vapors, corrosive vapors, and extreme cold.
07414-1
I

Model 7414A
Option
001
008
012
015
054
Part
Number
7414A
07754-60600
07754-60350
Section I
General Information
Table 1-2. Model 7414A Recording System, Equipment Options
Description
Four Channel Thermal Tip Recording System, 60 Hz, 115/230V ac; mint gray front
panels, jade green knobs, 440
Hz Oscillator for 8803A High Gain Preamplifier, and
2400
Hz Oscillator for 8805A Carrier Preamplifier; moss gray Bench Top Enclosure
07754-60261.
Rack mounting kit (Figure 2-7), with paper take-up tray and panel.
For 115/230V ac, 50
Hz operation.
Less one channel; right channel No. 4
is deleted, event marker installed between
channels 2and 3, extra marker cannot be installed with this option.
Extra monopolar marker installed between channels 2and 3; this marker cannot be
installed with Option 012.
Mounted in 1064B Mobile Cart; moss gray, with paper take-up drawer, blank panel.
Note: For acomplete System, order up to four 8800 Series Preamplifiers.
Figure 1-2. 8800 Series Preamplifiers
07414-1
1-3

Section I
General Information
1-15. MODEL 8801A
LOW GAIN DC PREAMPLIFIER.-
With amaximum sensitivity of 5mV/div, the 8801A
provides stable and precise amplification from dc to the
limit
of the recorder's capability, or up to 10kHz when
used with an oscilloscope or other indicator. The 8801A
features calibrated zero suppression with limits
of ±10 and
±100 volts.
1-16. MODEL 8802A MEDIUM GAIN DC PRE-
AMPLIFIER. -The 8802A has again
that is five times
greater than the 8801A and zero suppression to
±2 and ±20
volts. Except for the common-mode tolerance, which
is
smaller by afactor of five on the high sensitivity positions
of the RANGE control, the choice between the 8801A and
8802A depends directly
on signal input requirements.
1-17. MODEL 8803A
LOW LEVEL PREAMPLIFIER. -
With amaximum sensitivity
of 1IlV/div, corresponding to a
gain
of 100,000, the 8803A accommodates amuch wider
rqnge of signal amplitude (within abandwidth of dc to 100
Hz) than the 8801A and 8802A. The 8803A features a
fully-guarded input circuit, with afloating input and
common-mode rejection
as high as 160 dB at dc (120 dB at
60
Hz). In addition to ahigh rejection ratio, the input
circuit will tolerate acommon-mode voltage
as high as ±300
Vdc at any position
of the RANGE control. Calibrated zero
suppression
is provided in three maximum ranges: ±1, ±10,
and ±I00 volts with resolution to
10-
3.
1-18. MODELS 8805A/B CARRIER AMPLIFIER. -The
8805s measure any physical variable
that can be coupled to
asuitable transducer, i.e., strain
gage bridge, resistance or
reactance transducer, or differential transformer. Apartial
listing
of physical variables includes: strain, pressure, force,
velocity, flow and acceleration. A2400
Hz oscillator in the
recording system provides an excitation voltage which
is
amplified by abuffer amplifier in the 8805 to apower level
appropriate for exciting the external transducer, eliminating
the need for an external excitation circuit. The excitation
voltage, 5Vrms at 2400 Hz, can drive aload resistance
greater than 100 ohms; the amplifier will operate with
sources having
an internal impedance up to 5000 ohms at
the signal input terminals. Calibrated zero suppression
permits analyzing small signals when large static loads are
present on the transducer. Acalibration factor control
allows attenuation and zero suppression to be calibrated in
terms
of transducer load units.
1-19. MODEL 8806B PHASE-SENSITIVE DEMODU-
LATOR. -The 8806B provides adc
output proportional
1-4
Model 7414A
to the rms value
of an input signal component that is in
phase,
or 1800 out of phase with respect to an external ac
reference voltage. For flexibility, the phase-reference volt-
age can be shifted to any phase angle by three plug-in
calibrated phase shifters, available for frequencies
of 60,
400,
or 5000 Hz. Afourth plug-in phase shifter covers six
frequency bands from 50
Hz to 40 kHz and provides for
continuous phase shifting from 00to 3600•Other features
include transformer isolation for
both the signal and refer-
ence voltage circuits, and amaximum calibrated sensitivity
of 0.5 mV rms/div, corresponding to again of 200 (rms ac
to dc).
1-20. MODEL 8807A
AC TO DC CONVERTER. -The
8807Aprovides adc voltage
output proportional to the
average value
of afull-wave rectified ac input signal. Range
sensitivity
is calibrated in terms of rms, for sinusoidal
waveforms. The
input circuit is transformer coupled, float-
ing, and guarded for high common-mode rejection, allowing
measurements over awide range
of input signal conditions:
3mV to 500 Vrms, from 50
Hz to 100 kHz. Calibrated
zero suppression and variable scale expansion permit clear
analysis
of small excursions in large input signals.
1-21. MODEL 8808A LOG LEVEL PREAMPLIFIER. -
The 8808A contains compression and full-wave detection
circuits
that provide an output proportional to the log} 0 of
the ac input signal amplitude, expressed in decibels, where
zero decibels
is taken as a 1 volt rms sine-wave input
voltage. The unit provides for 50
dB and 100 dB ranges,
with full-span outputs corresponding to ±2.5 volts or 0to
+5 volts. Input signals from 3 mv to 300 Vrms may be
recorded without changing ranges; avoltage ratio
of
100,000 (100 dB).
1-22. MODEL 8809A SIGNAL COUPLER. -The 8809A
is alow cost, solid state preamplifier with selectable high or
low
input impedance and aGAIN control. It is used for
simple signal coupling
to an HP direct writing recorder, in
single and multichannel systems.
1-23. Accessories.
1-24. For alist of recorder accessories, refer to Table 6-1,
Assembly A19, Accessories. Order accessories by their
individual part numbers. For other system accessories, refer
to the separate equipment manuals provided with the
recording system.
07414-1
I

Model 7414A
2-1. INITIAL INSPECTION.
SECTION II
INSTALLATION
2-11. INSTALLATION.
Section II
Installation
I I
I
2-2. Initial inspection consists of acheck for physical
damage incurred during shipping, and the completion of all
performance tests. See Figure 2-1 for Recorder inspection
particulars.
2-3. Mechanical Check.
24. If damage to the shipping carton is evident, notify the
HP Sales/Service Office and unpack the equipment in the
presence of the carrier's agent. Upon unpacking, inspect the
instrument for mechanical damage such as scratches, dents,
broken knobs, or other defects. Also check the cushioning
maieri'! ls for signs of severe stress during handling.
2-5. Performance Tests.
2-6. The electrical and mechanical performance of the
Model 7414A Thermal Tip Recording System may be
verified upon receipt, using performance tests described in
Section V, Maintenance. An 8800-Series Preamplifier must
be in place for these tests.
2-7. Damage Claims.
2-8. If the instrument is damaged in transit, notify the
carrier and the nearest Hewlett-Packard Sales/Service Office
immediately. For your convenience, alist of these offices is
located in the rear of this manual. Keep the shipping carton
and packaging material for the carrier's inspection. The
Sales/Service Office will arrange for repair or replacement
of the System without waiting for claim settlements from
the carrier.
2-9. STORAGE.
2-10. If the Recording System is to be stored for aperiod
of time, wrap the front panels in protective padding and
seal the equipment in a moisture-proof covering. Repackage
the System in a container similar to the original factory
carton. If the System is installed in aBench Top Enclosure,
leave it mounted in the enclosure. If it is installed in a
Mobile Cart or equipment rack, remove it from the cart or
rack to facilitate moistureproof packaging. If long-term
storage is anticipated, pull the paper table out at the Cart
drawer and unlatch it. This will prevent aflat spot from
developing on the drive roller from the spring-loaded
pressu re rolle r.
07414-1
2-12. Recording Systems installed in the Bench Top Enclo-
sure do not require installation instructions. For access to
the Recorder, loosen knobs at the front of the case and
raise the top cover (see Figure 2-1). If the Recorder is
installed in aMobile Cart, release the four front-panel
shipping screws to slide the Recorder out for receiving
inspection and performance checks (see Figure 2-1). If the
Recorder is installed in an existing equipment rack, the rack
slides must be installed before mounting the Recorder
(Option 001).
2-13. Preamplifier Installation.
2-14. The Recording System is shipped with all preampli-
fiers installed. To change apreamplifier, perform the
following steps.
a. Switch off Recorder power.
b. Loosen the top and bottom front panel screws and
pull the preamplifier straight ou t.
c. Insert the replacement preamplifier into the channel
guide, push firmly to mate connectors, and tighten screws
at the top and bottom of the front panel.
2-15. Power Connections.
2-16. Check that the power line voltage and frequency is
the same as that shown on the Recorder nameplate, located
on a shelf at the left side of the rear panel (see Figure 2-2).
Note locations of the fuses.
2-17. When making power connections, push the POWER
button on the front panel so that it protrudes and a
Z-shaped line appears. Otherwise, the recorder will start
when the power cord is plugged in. Refer to Figure 2-3 and
perform the following steps for Mobile Cart power connec-
tions.
a. Connect a ground wire (as shown) to agood earth
ground, such as acold water pipe.
b. Check that the paper take-up drawer is grounded with
a strap, and that the recorder chassis is grounded to the
cart.
c. Plug the power cord connector into the recorder
POWER INPUT jack, and into the line receptacle built into
the cart.
d. Connect the cart power cord to a3-wire line outlet,
completing the power connections.
2-1

Section n
Installation
REMOVE 2 SCREWS
FOR ACCESS TO
RETAINING SCREWS
Model 7414A
TYPICAL
RETAINING
SCREWS
Press front slide locks to slide recorder back into cart or
cabinet.
WARNING: DO NOT ACTUATE REAR SLIDE LOCKS
UNLESS RECORDER IS SUPPORTED FOR REMOVAL.
Press rear slide locks to slide recorder completely out of
retaining slides.
I
2-2
Figure 2-1. Recorder Access for Receiving Inspection
07414·1

Model 7414A
AUXILIARY SIGNAL DRIVER AMPLIFIERS
r------===~======----------" I~-====:::::c=====------..
Section II
Installation
J24
SIGNAL
INPUT
F3----~r- ......
F4
F5
FUSE COMPLEMENT
Reference
Designator
J23 J22
Service
J21 J19 J18
J8
POWER
OUT/REMOTE
J16 J15
S4
F1
i-+;-'-F2
J5 POWER IN
Value and
Type
F1
F2
F3
F4
F5
F6 (not shown)
AC Power, 115V Service
AC Power, 230V Service
Recorder, 115V Service
Recorder, 230V Service
+20V dc
-20V dc
-24V dc
2400
Hz Oscillator (Option 004) -20V dc
supply -
See Figure 6-7.
6A
3AT
2.5AT
1.25AT
3AT
3AT
3AT
100mAT
Figure 2-2. Recorder Rear Panel Connections and Fuse Locations
07414- i
2-3

Figure 2-3. Recorder and Mobile Cart Power Connections
Section II
Installation
CART POWER CORD
TO
WALL OUTLET
POWER
OUTLETS
BARE COLD WATER PIPE
OR OTHER EARTH GROUND
RECORDER POWER
CORD
MOBILE CART
GROUNDING WIRE
DRAWER GROUNDING
STRAP
Model 7414A
,
2-18. Signal Connections.
2-19.
For signal connection information relative to the
individual preamplifiers, refer to the preamplifier instruc-
tion manuals. Also refer to Figure 2-4 for adescription
of
signal cable preparation for the 8800-Series Preamplifiers.
2-20. Tape System Connections.
2-21.
If an instrumentation tape recorder is to be used with
the Recording System, the addition
ofa 4681A or a 4682A
2-4
Control Section
is recommended. Connections for the
Recorder and
the Control Sections are shown in Figure 2-5.
2-22. Remote Control and Marker Connections.
2-23. Aremote
control and marker plug is supplied with
the Recorder
as an accessory. To make remote control
connections for operating the Recorder and the Event
Marker, make the cable connections shown in Figure 2-6,
using the HP parts noted in the illustration.
07414-1
1

II
IIModel 7414A Section II
Installation
SIGNAL CONNECTOR PREPARATION
I II
a. Slide the prepared end of the cable into the cable clamp and through the
connector shell. Also slide the end of the cable through the guard shield
extension, for guarded input circuits.
For non-guarded input circuits,
remove and store the guard shield extension.
b. Wire the connector according to the diagram below, according to
preamplifier to be used. For guarded input circuits, slide the guard shield
extension
into place after soldering the signal leads to terminals Aand B.
c. Press the connector block carefully into the connector shell.
d. Insert the retaining ring.
e. Tighten the cable screws.
f. Check with an ohmmeter to determine that the cable shields are not
shorted to
the connector shell or to each other.
Connector HP 1251-1895
GUARD
~ CABLE SHIELD
I CLAMP ~
~
, ETAINER
~ RING
~~.~. INSULATOR
\%i ,BLOCK
'" GUARD SHIELD
EXTENSION
SHELL
SIG+ ......... ~---.
1/4 1/4 1/4 1/4 SHIELD
~
t CONNECTION
Double- ---
Shield Cable lq
HP 8120-0800 cO~'i:~~~I:;: 3/4 ~ 1-1/4 ~
,-, -
SIG - -+--+-L-.l..--~
SIG - -++-----,
SIG+
PREAMPLIFIER
MODEL
8803A
8806B *
8807A **
GUARDED CABLE PREPARATION
Single-
Shield Cable
HP 81 20-0718
NOTES:
!I
I II
*1. Connect Ref voltage to pins Aand B on
auxiliary connector of the power supply. **
1. AC output available on pin C of aux iliary connector
of the power supply.
2. DC input (8807A, Opt 02) available on pins A and B
of auxiliary connector of the power supply.
2
SIG - -;'--H-'---~
S IG + .....:....~----.
Double-
Shield Cable
HP 8120-0800
1/4 1/4 1/4
~M~,~IELO
~NECTION
1--
1-1/4
SIG -......... +-----,
SIG+
PREAMPLIFIER
MODEL
8801A
8802A
8808A
8809A
"NOTE:
NON-GUARDED CABLE PREPARATION
Single-
Shield Cable
HP 8120-0718
II
I
I!
Single conductor sh ielded cable can be used
by connecting center conductor to pin Aand
shield to pin B.
CARRIER PREAMPLIFIER CABLE PREPARATION
II
PREAMPLIFIER
MODEL
8805A
8805B
HP Transducers having 5-pin AN connectors (pin
pattern 0 ) use I nput Adapter 14060B for sig-
nal input connections. For other signal sources,
connect the input signals as shown. The transducer
output leads and transducer excitation leads must
be twisted and enclosed in braided shielding.
II
Figure 24. 7414A System Input Cable Preparation
I
I
II
07414-1
2-5

Section III
Operation
345
Model 7414A
6
II
II
II
1. RECORDER POWER SWITCH: Press to apply
power; press to remove power. Back-lighted with
power applied.
2.8800-SERIES PREAMPLIFIERS: Refer to the
individual instruction manuals for control infor-
mation.
3. MODE CONTROL BUTTONS: Pressing the
STDBY button holds the styli of all channels at
chart center during Recorder operation. The
REMOTE button transfers control of the Recorder
"run mode" to a remote location. The RUN
button starts the chart drive, applies heat to the
styli and signals to the recording circuits.
4.
SPEED MM/SEC CONTROL BUTTONS: Nine
speed
selection buttons select standard chart
speeds from 0.25 to 100 mm/second. Button
remains depressed to indicate selected chart speed.
5.
TIMER BUTTONS: The OFF button-turns off the
interval timing marker. The SEC button selects
timing marks at 1-second intervals. The MIN
button selects timing marks at 1-minute intervals.
The EVENT MARKER button applies a marker
pulse when pressed, to mark events in the process
being
recorded.
6. STYLUS HEAT CONTROLS: Individual controls
adjust the heat at each stylus tip, and thereby the
trace width. More stylus heat is generally required
for high-frequency signals than low-frequency
signals. Once adjusted, stylus heat is automatically
regulated to compensate for changes in chart paper
speed.
7. PAPER
TAKEUP DRAWER (CART): The takeup
drawer pulls out to receive used chart paper. For
Bench Top Enclosure models, a paper takeup shelf
is provided. Install as shown in Figure 3-2.
II
II
II
Ij
II
3-2
Figure 3-1. 7414A Recording System, Control Locations
07414-1
II
II

Model 7414A Section III
Operation
1. UNWRAP PAPER and remove cardboard. Make sure highest odd
number is on top of pack. 2.
PULL PAPER TABLE OUT AT BdTTOM.
3. LOWER IT SLOWLY. It must be fully horizontal.
4. SLIDE PAPER PACK INTO FEED TRAY while compressing paper,
and
pulling top sheet out.
6. CLOSE PAPER TABLE, pulling down slightly on paper. Press table
in
firmly so it locks in place.
Note that tab on takeup tray
catches
in hole on case lip.
9. IF RECORDER IS IN A CART OR A CABINET, PULL OUT
PAPER TAKEUP DRAWER. Odd-numbered sheet should be first
into drawer.
8.
IF RECORDER IS IN ACASE, IN TALL TAKEUP TRAY. Note
that an odd-numb red sheet should b first onto tray.
Figure 3-2. Paper Loading Procedure
07414-1
3-3