
Theory of Operation
Detailed Circuit Description
4
4-23
Control and Switching Section
4-38.
Refer to page 2 of the Current Amplifier schematic. Relays K201 through 209, Q214
through 216, and U209 through 210 configure the Current Amplifier circuitry for the
following six modes:
•
Current Standby
Current Amplifier input is active through K201. Current Amplifier output is
disconnected from instrument output terminals but is routed through the sense path
through K202.
•
Operate1
Input is connected to BOOST IN and MCOM. Output is connected to front or rear
output terminals. FET switches Q211 and Q213 are off, enabling the error amplifier
circuitry. Operate1 is the active mode for delivering up to 11A (ac or dc) to a UUT.
•
Operate2
The Current Amplifier is configured as in standby mode, except K201 is off. 5700A
current source is routed to the 5725A current output terminals through K205.
Operate2 is the active mode for delivering 2.2A or less to the 5725A terminals
unless the 5725A 11A current range has been explicitly enabled from the 5700A
front panel or by remote command.
•
Calibrate1 (Shunt Calibration)
Input is shorted. Error amplifiers are disabled with Q211 and Q213. Output is routed
directly to current return path through K207, bypassing sense circuits. 5700A current
source is routed through K206 to the 5725A current sense path. Procedures
performed during Calibrate1 determine the value of R272. This is one of the factors
in the dc gain and the only factor in the ac gain of the Current Amplifier.
•
Calibrate2 (Offset Calibration)
The amplifier is configured as in Calibrate1, except with its output routed by K208
to the 5700A. Procedures performed during Calibrate2 determine the dc offset of the
Current Amplifier.
•
Calibrate3 (Gain Calibration)
Input is connected to BOOST IN, B-FEEDBACK, and MCOM as in Operate1, but
Output is routed through the current sense path through K202. Output is not
connected to output terminals. Procedures performed during Calibrate3 determine
the gain of the error amplifier, the other factor in the dc gain of the Current
Amplifier.
Power Supply Section
4-39.
Refer to page 3 of the Current Amplifier schematic. The unregulated, high-current
supply is made from K208 through 209, F201 through 202, CR206, and C218 through
C221.
The regulated
±
20V supplies are composed of RT201 through 202, U205, U206, CR212
through 215, C222, C223, and associated components. Thermistors RT201 and RT202
are PTC thermistors for current limiting and transformer protection.
Summary of Contents for 5725A
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Page 6: ...5725A Instruction Manual iv...
Page 8: ...5725A Instruction Manual vi...
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Page 46: ...5725A Instruction Manual 3 2...
Page 62: ...5725A Instruction Manual 4 4 Figure 4 1 5725A Overall Block Diagram...
Page 78: ...5725A Instruction Manual 4 20 aq20f eps Figure 4 3 Current Amplifier Assembly Block Diagram...
Page 96: ...5725A Instruction Manual 4 38...
Page 98: ...5725A Instruction Manual 5 2...
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Page 118: ...5725A Instruction Manual 7 2...
Page 126: ...5725A Instruction Manual 7 10...
Page 128: ...5725A Instruction Manual 8 2...
Page 132: ...5725A Instruction Manual 8 6 aq24f tif Figure 8 1 Final Assembly...
Page 133: ...List of Replaceable Parts 8 8 7 aq25f tif Figure 8 1 Final Assembly cont...
Page 134: ...5725A Instruction Manual 8 8 aq26f tif Figure 8 1 Final Assembly cont...
Page 135: ...List of Replaceable Parts 8 8 9 aq27f tif Figure 8 1 Final Assembly cont...
Page 136: ...5725A Instruction Manual 8 10 aq28f tif Figure 8 1 Final Assembly cont...
Page 137: ...List of Replaceable Parts 8 8 11 aq29f tif Figure 8 1 Final Assembly cont...
Page 138: ...5725A Instruction Manual 8 12 aq30f tif Figure 8 1 Final Assembly cont...
Page 139: ...List of Replaceable Parts 8 8 13 aq31f tif Figure 8 1 Final Assembly cont...
Page 141: ...List of Replaceable Parts 8 8 15 5725A 1611 aq36f eps Figure 8 2 A1 Interconnect PCA...
Page 145: ...List of Replaceable Parts 8 8 19 5725A 1650 aq37f eps Figure 8 3 A2 Current Amplifier PCA...
Page 149: ...List of Replaceable Parts 8 8 23 5725A 1661 aq38f eps Figure 8 4 A3 High Voltage Amplifier PCA...
Page 153: ...List of Replaceable Parts 8 8 27 5725A 1631 aq39f eps Figure 8 5 A4 Power Supply PCA...
Page 155: ...List of Replaceable Parts 8 8 29 5725A 1650 aq40f eps Figure 8 6 A5 Digital PCA...
Page 159: ...List of Replaceable Parts 8 8 33 5725A 1601 aq41f eps Figure 8 7 A6 High Voltage Sense PCA...
Page 161: ...List of Replaceable Parts 8 8 35 aq32f tif Figure 8 8 A12 Transformer Enclosure Assembly...
Page 162: ...5725A Instruction Manual 8 36 aq33f tif Figure 8 8 A12 Transformer Enclosure Assembly cont...
Page 163: ...List of Replaceable Parts 8 8 37 aq34f tif Figure 8 8 A12 Transformer Enclosure Assembly cont...
Page 164: ...5725A Instruction Manual 8 38 aq35f tif Figure 8 8 A12 Transformer Enclosure Assembly cont...
Page 166: ...5725A Instruction Manual 8 40...
Page 168: ...5725A Instruction Manual 9 2...
Page 169: ...Schematic Diagrams 9 3 9 Figure 9 1 A1 Interconnect PCA 5725A 1611 aq48f eps...
Page 170: ...5725A Instruction Manual 9 4 Figure 9 1 A1 Interconnect PCA cont...
Page 171: ...Schematic Diagrams 9 5 9 Figure 9 1 A1 Interconnect PCA cont...
Page 172: ...5725A Instruction Manual 9 6 Figure 9 2 A2 Current Amplifier PCA 5725A 1650 aq52f eps...
Page 173: ...Schematic Diagrams 9 7 9 Figure 9 2 A2 Current Amplifier PCA cont...
Page 174: ...5725A Instruction Manual 9 8 Figure 9 2 A2 Current Amplifier PCA cont...
Page 175: ...Schematic Diagrams 9 9 9 Figure 9 2 A2 Current Amplifier PCA cont...
Page 176: ...5725A Instruction Manual 9 10 Figure 9 3 A3 High Voltage Amplifier PCA 5725A 1661 aq56f eps...
Page 177: ...Schematic Diagrams 9 11 9 Figure 9 3 A3 High Voltage Amplifier PCA cont...
Page 178: ...5725A Instruction Manual 9 12 Figure 9 3 A3 High Voltage Amplifier PCA cont...
Page 179: ...Schematic Diagrams 9 13 9 Figure 9 4 A4 Power Supply PCA 5725A 1631 aq59f eps...
Page 180: ...5725A Instruction Manual 9 14 Figure 9 4 A4 Power Supply PCA cont...
Page 181: ...Schematic Diagrams 9 15 9 Figure 9 4 A4 Power Supply PCA cont...
Page 183: ...Schematic Diagrams 9 17 9 Figure 9 5 A5 Digital PCA cont...
Page 185: ...Schematic Diagrams 9 19 9 Figure 9 6 A6 High Voltage Sense PCA cont...
Page 186: ...5725A Instruction Manual 9 20 Figure 9 6 A6 High Voltage Sense PCA cont...
Page 187: ...Schematic Diagrams 9 21 9 Figure 9 6 A6 High Voltage Sense PCA cont...
Page 188: ...5725A Instruction Manual 9 22 Figure 9 6 A6 High Voltage Sense PCA cont...
Page 189: ...Schematic Diagrams 9 9 23 aq45f eps Figure 9 7 A12 Transformer Enclosure Assembly...
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