HP SCR-1P Series Service manual

DC POWER SUPPLY
SCR-lP SERIES, MODEL 6443B
SERIAL NUMBER PREFIX 6G
OPERATING AND SERVICE MANUAL
HEWLETT
PACKARD HARRISON
DIVISION

DC POWER SUPPLY
SCR -l P SERIES, MODEL 6443B
SERIAL NUMBER PREFIX 6G
June, 1966
~ Stock No. 06443-90001

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Sectio n
I
II
III
TABLE OF CONTENTS
GENERAL INFORMATION •
1-1. Description. • •
1-2 • General • . • .
1-4. Overload Protection
1- 7. Cooling • • • • •
Title
1-9 • Monitoring • . • . • • • .
1-11. Output Terminals
1-13. Instrument Identification
INSTALLATION . . . .
2-1. Initial Inspection
. . . .
2-2. General
. . . .
2-4.
Mechanical Check • . .
2-6.
Electrical Check. .
2 -8.
Installation Data
. . . .
2-9.
General . . . .
2-11.
Location
. . .
2-13. Power Requirements
2-15.
Power Cable
. . . .
2-18. Repackaging for Shipment.
OPERATING INSTRUCTIONS. .
3-1. Controls and Indicators
. .
. .
. .
. .
.
. .
. .
. .
. .
. .
3-3. Operation ..•.•• ••
3-4. General . . • . • . . . .
3-6. Normal • • • • .
3-10 . Connecting Load.
3-14. Remote Sensing • • • • • .
3-17 . Remote Programming
3-26. Parallel • • • . . . . .
3
-30. Series . • • • • •
3- 35 . Auto-Tracking . • •
3-38. Operating Considerations.
3-39. Pulse Loading . • • . .
3-41. Output Capacitance . .
3-44. Negative Voltage Loading
3-46. Negative Current Loading ..
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Page
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. 1-1
. 1-1
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. 1-1
. . . 1-2
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2-1
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2-1
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2-1
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. 2 -1
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. . 2- 2
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2-2
. 2-2
. 3 -1
.. 3- 1
• 3 -1
. 3-1
. 3-1
. 3-2
. .. 3-2
• . • 3-3
. 3-5
. 3-5
. • . . . . 3-6
• 3-7
. 3-7
. . . . . 3-7
. 3- 7
. . . . 3-7

Section
IV
v
TABLE OF CONTENTS (cont.}
Title Page
PRINCIPLES OF OPERATION . . . . . . . . . . .4-1
4-1.
Block Diagram Description . . .
.4-1
4-9.
Circuit Description • . . . . . . . . . . . .4-2
4-1 0.
AC Input.
. . . . . . . . . .
.4-2
4-12.
DC Output • . . . . . . . . ..
4-2
4-14.
Voltage Input • . . . . . . . .4-2
4-20.
Current Input . . . . . . . .4-3
4-24.
Ga ting Circuit
. . . .
.4-4
4-27.
Turn-On Circuit.
. . . . . . . . .
.4-4
4-29. SCR Regulator Control • . . . . . .4 -4
4-37. SCR Regulator
. . . . . . . . . . . . . . . . . .
.4-6
4-42.
Bias and Reference Circuit . .
.4-6
MAINTENANCE . • . • . • . . .
5-1
5-1. General . ........... . . 5-1
5-3. Measurement Techniques . • • • • •• 5-1
5-7. Performance Check • • . . . • • • . • • .
.•• 5-2
.5-2 5-8. General . . . . . . . . . . .
5-10. Rated Outpu t and Meter Accuracy • . •• 5-2
5-13. Line Regulation . . . . . . • • . • . • • . . 5-3
.5-4
5-16 • Load Regula ti on. . . . . . . . • •
5-19. Ripple and Noise • . . . . ...
5-21. Transient Recovery Time ...•.•.
5-23. Additional Specification Check
5-24. Temperature Coefficient .
5-2 7. Output Stability. . •
. . . . . . . 5-4
. . . . . . . . 5-5
. 5-6
. . 5-6
.5-6
5-30. Remote Programming . . . . . . . . . . . . .
5-7
5-33. Output Impedance . .
5-35. Output Inductance.
5-3 7. Cover Removal .
5-3 9 • Troubleshooting . . •
5-40. General . • . • •
5-42. Trouble Analysis
5-49. Repair and Replacement • . • • •
5-51. Adjustments and Calibrations.
5-52. General • • • • • . . • • •
5-54. Meter Zero. • • • .
5-56. Voltmeter Tracking. . . • . .
.5-9
. . . . . . 5-9
• • . . . • 5-10
.5-10
. • 5-10
• • 5-10
• • • • . • 5-12
.5-14
. . . . . . . 5-14
. • 5-14
. ..• 5-14
5-58., Ammeter Tracking . • • • • • . • • .
.•. 5-14
.. 5-15
. • 5-15
. • • . • 5-15
5-60. Constant Voltage Programming Cu.rrent
5-62. Zero Voltage Output . • • • • • • • • • • .
5-64. Constant Current Programming Current •
ii
/

Section
VI
5-66.
5-68.
5-70.
5-72.
TABLE OF CONTENTS (cont.)
Title
Zero Current Output . . . . . . .
Bias and Reference Line Regulation
Line Imbalance . • • . . . . .
Constant Current Load Regula tion .
REPLACEABLE PARTS . . • . .
6
-1. Introduction • • • • .
6
-4. Ordering Information.
iii
Pa ge
. . . 5-16
. . 5-16
.5-17
. 5-18
. .6-1
.6 -1
.6-1

-

-
Table 1-1.
INPUT:
RATED OUTPUT:
LINE REGULATION:
LOAD REGULATION:
RIPPLE AND NOISE:
OPERATING TEMPERATURE RANGE:
STORAGE TEMPERATURE RANGE:
TEMPERATURE
COEFFICIENT:
OUTPUT STABILITY:
(after 30-minute warm-up)
REMOTE PROGRAMMING:
TYPICAL OUTPUT IMPEDANCE:
OUTPUT INDUCTANCE:
Specifications
_ 105-125 vac, 57 to 63 cps, single phase,
6. 5 amperes, 400 watts max.
Constant Voltage: 0 to 120 vdc.
Constant Current: 0 to 2. 5 amperes de
Constant Voltage: Less than 60 mv for
10 5-12 5 vac input change.
Constant Current: Less than 25 ma for
105-I25 vac input change.
Constant Voltage: Less than 120 mv for
0 to 2. 5 ampere load change.
Constant Current: Less than 25 ma for
0 to 12 0 vdc load change.
240 mvrms
Constant Voltage: 0. 05% plus 30 mv
per degree centigrade.
Constant Current: 8 ma per degree
centigrade.
Constant Voltage: O.I5% plus 90 mv
for 8 hours at constant temperature.
Constant Current: 25 ma for 8 hours
at constant temperature.
Constant Voltage: 300 ohms per volt ±.I%
Constant Current: I 00 ohms per ampere
Less than O. I ohm from de to o. 5 cps
Less than 2. 0 ohm from 0. 5 cps to IOO cps
Less than •5 ohm from 100 cps to Ike
Less than 4. 0 ohm from Ike to IOO kc
2. 0 microhenry

Table 1-1. Specifications (cont.)
TRANSIENT RECOVERY TIME:
SIZE AND WEIGHT:
FINISH:
!' ¥
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~
CJ
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(f\~ \IC)l_flGI: ------:1..
4' ·® -e
In constant voltage operation, less than
300 milliseconds is required for output
voltage recovery to within 600 millivolts
of the nominal output voltage following a
load change equal to one half the maximum
current rat,ing of the power supply.
Nominal output voltage is defined as the
mean between the no-load and full-load
voltages. The transient amplitude is' less
than 4. 0 volt per ampere for any load
change between 20% and 100% of rated
output current. (Excluding the initial spike
of approximately 100 microseconds dura-
tion which is significant only for load rise
times faster than 0 .2 ampere per micro-
second.)
Heioht Width
3-1/2 in. 19 in.
Depth
17-1/2 in.
Weight
31 lb.
Light gray front panel with dark gray case.
CJ
~
•
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)- '"' '
+ -
~CUM0-1~
... .
-e •
Figure 1-1. Model 64438 DC Power Supply

SECTION I
GENERAL INFORMATION
l::l. DESCRIPTION
1-2. GENERAL
1-3. The H-Lab Model 6443'A DC Power Supply (fig. 1- 1) is a completely solid-
state, compact, well - regulated, constant voltage/constant current de power supply
suitable for either bench or relay rack operation. A three-wire five-foot power cord
is provided . The output is continuously variable between 0 and 12..Qvdc, and be-
tween 0 and 2. . 5amperes. Detailed specifications are given in table 1-1.
1-4.
OVERLOAD PROTECTION
1-5. A crossover feature protects both power supply and load in constant voltage
operation. Automatic crossover circuitry switches the power supply from constant
voltage to constant current operation if the output current exceeds a preset limit.
This crossover circuitry also protects the load from overvoltage during constant
current operation by automatically switching the power supply into constant voltage
operation . The user can adjust the crossover point via the front panel controls
(para. 3-8 and 3-9) •
1-6. The power supply is protected from reverse voltage (positive voltage applied
to negative terminal) by a diode that shunts current across the output terminals
when this condition exists . The ac input is fused. A double-pole on/off switch
opens both power leads in the off position.
1-7. COOLING
1-8. Convection cooling is used. No fan is required . The power supply has no
moving parts (except meter movement).
1-9. MONITORING
1-10. Two front-panel meters are provided for monitoring output voltage and current.
The voltmeter has .a 0 tol 2·D volt range and the ammeter has a 0 to 3 ampere range.
Each meter has a 2% accuracy at full scale.
1-11 • OUTPUT TERMINALS
1-12. Output power is available via a terminal strip on the rear panel. The rear
panel terminal strip also enables the power supply to be connected for different
modes of operation (para. 3-3). The output terminals are isolated from the chassis
1-1