SERVICE MANUAL AUTORANGING DC POWER SUPPLY AGILENT MODELS 6023A and 6028A Agilent Part No. 5964-8283 FOR INSTRUMENTS WITH SERIAL NUMBERS Agilent Model 6023A; Serials US36490101 and above Agilent Model 6028A; Serials US36520101 and above For instruments with higher serial numbers, a change page may be included. Microfiche Part No.
CERTIFICATION Agilent Technologies certifies that this product met its published specifications at time of shipment from the factory. Agilent Technologies further certifies that its calibration measurements are traceable to the United States National Institute of Standards and Technology, to the extent allowed by the Institute’s calibration facility, and to the calibration facilities of other International Standards Organization members.
SAFETY SUMMARY The following general safety precautions must be observed during all phases of operation, service and repair of this instrument. Failure to comply with these precautions or with specific warnings elsewhere in this manual violates safety standards of design, manufacture, and intended use of the instrument. Agilent Technologies, Inc. assumes no liability for the customer's failure to comply with these requirements. BEFORE APPLYING POWER.
SAFETY SYMBOL DEFINITIONS Symbol Description Symbol Description Direct current Terminal for Line conductor on permanently installed equipment Alternating current Caution, risk of electric shock Both direct and alternating current Caution, hot surface Three-phase alternating current Caution (refer to accompanying documents) Earth (ground) terminal In position of a bi-stable push control Protective earth (ground) terminal Out position of a bi-stable push control Frame or chassis terminal On (
TABLE OF CONTENTS Introduction ............................................................................................................................................................................ 7 Scope .................................................................................................................................................................................... 7 Calibration and Verification ........................................................................................
Overvoltage Protection (OVP) Circuit............................................................................................................................ 49 Power-Limit Comparator ................................................................................................................................................ 49 Control-Voltage Comparator ..........................................................................................................................................
1 Introduction Scope This manual contains information for troubleshooting the Agilent 6023A or 6028A 200W Autoranging Power Supply to the component level. Wherever applicable, the service instructions given in this manual refer to pertinent information provided in the Operation Manual. Both manuals cover Agilent Models 6023A/28A; differences between models are described as required. The following information is contained in this manual.
Manual Revisions Agilent Technologies instruments are identified by a 10-digit serial number. The format is described as follows: first two letters indicate the country of manufacture. The next four digits are a code that identify either the date of manufacture or of a significant design change. The last four digits are a sequential number assigned to each instrument. Item Description US The first two letters indicates the country of manufacture, where US = USA; MY = Malaysia.
2 Calibration and Verification Introduction This section provides test and calibration procedures. The operation-verification tests comprise a short procedure to verify that the unit is performing properly, without testing all specified parameters. After troubleshooting and repair of a defective power supply you can usually verify proper operation with the turn-on checkout procedure in the Operating Manual.
Table 2-1. Test Equipment Required TYPE Oscilloscope REQUIRED CHARACTERISTICS Sensitivity: 1 mV Bandwidth: 20MHz & 100MHz Input: differential, 50Ω & 10MΩ USE P,T RECOMMENDED MODEL Agilent 1740A RMS Voltmeter True rms, 10MHz bandwidth Sensitivity: 1 mV Accuracy: 5% P Agilent 3400B Logic Pulser 4.5 to 5.5Vdc @ 35mA T Agilent 546A Multimeter Resolution: 100nV Accuracy: 0.
Table 2-1. Test Equipment Required (continued) TYPE Switch DC Power Supply REQUIRED CHARACTERISTICS SPST, 30A @ 20V Voltage range: 0-60Vdc Current range: 0-3Adc USE P T,P Variable Voltage Transformer (autotransformer) Range greater than -13% to +6% of nominal input AC voltage 1KVA P,A P = performance testing A = calibration adjustments RECOMMENDED MODEL Agilent 6296A T = troubleshooting * Resistors may be substituted for test where an electronic load is not available.
Table 2-2. Calibration Procedure TEST Meter F/S Adjust. TESTED VARIABLE Meter Ref. Voltage TEST POINTS A2J3 pin 6 ( + ) M(-) TEST SEQUENCE AND ADJUSTMENTS a. b. Resistance Programming F/S Adjust. Prog. Voltage VP ( + ) P(-) a. b. c. V-MON Zero Adjust. V-MON VM ( + ) M(-) a. b. c. d. Common Mode Adjust. Residual Output Voltage VM( + ) VM ( + ) M(-) a. b. c. d. I-MON Zero Adjust. I-MON IM ( + ) M (-) I-MON F/S Adjust. I-MON IM ( + ) M(-) e. f. a. b. c. a. b. c. d.
Table 2-2. Calibration Procedure (continued) TEST Power Limit Adjust. TESTED VARIABLE V(OUT) I(OUT) TEST POINTS TEST SEQUENCE AND ADJUSTMENTS a. Perform I-MON F/S Adjust before proceeding. b. Connect the unit to the ac power line via the external variable auto-transformer which is set to nominal line voltage. c. Connect a 0.25Ω, 250W (6023A), 2.3Ω, 250W (6028A) resistor across the unit's output and turn on ac power. d. Set voltage control to 9V (6023A) 9V≥ 3V (6028A) and current control to 30.
Table 2-3. Guide to Recalibration After Repair Printed Circuit Board A1 Main Board A1 Main Board A4 Power Mesh A4 Power Mesh A2 Control Board A2 Control Board A2 Control Board A2 Control Board A2 Control Board A2 Control Board 1. 2. 3. Block Name Constant Voltage (CV) Circuit Constant Voltage (CV) Circuit Constant Current (CC) Circuit Power Limit Comparator Bias Power Supplies Circuit Within Block All Except Current Source Current Source Ref.
The substitution of the load resistor requires adding a load switch to open and short the load in the CC or CV load regulation tests. The load transient recovery time test procedure cannot be performed using load resistors. An electronic load is considerably easier to use than a load resistor.
Figure 2-3. Basic Test Setup d. e. f. g. Reduce the resistance of the load to draw an output current of: 29Adc (6023A) 10Adc (6028A) Check that the unit's CV LED remains lighted. Record the output voltage at the digital voltmeter. Open-circuit the load. When the reading settles, record the output voltage again. Check that the two recorded readings differ no more than: ± 0.0027Vdc (6023A) ± 0.0090Vdc (6028A) Source Effect (Line Regulation).
f. g. h. Record the output voltage at the digital voltmeter. Adjust autotransformer to the maximum for your line voltage. When the reading settles record the output voltage again. Check that the two recorded readings differ no more than: ± 0.0030Vdc (6023A) ± 0.0080Vdc (6028A) PARD (Ripple And Noise). Periodic and random deviations (PARD) in the unit's output-ripple and noise-combine to produce a residual ac voltage superimposed on the dc output voltage.
the unit's output voltage. To reduce common-mode noise pickup, set up the oscilloscope for a differential, two-channel voltage measurement. To reduce normal-mode noise pickup, use twisted, 1 meter or shorter, 50Ω coaxial cables with shields connected to the oscilloscope case and to each other at the other ends. Proceed as follows: a. b. c. d. e. f. Connect the test equipment as shown in Figure 2-5. Operate the load in constant resistance mode (Amps/Volt) and set resistance to maximum.
6023A 6028A Figure 2-6. 20KHz Noise, CV Peak-to-Peak PARD Load Transient Recovery Time. Specified for CV operation only; load transient recovery time is the time for the output voltage to return to within a specified band around its set voltage following a step change in load. Proceed as follows: a. b. c. d. e. f. g. Connect the test equipment as shown in Figure 2-3. Operate the load in constant-current mode and set for minimum current.
6023A 6028A Figure 2-7. Load Transient Recovery Waveform Temperature Coefficient. (6023A) Temperature coefficient (TC) is the change in output voltage for each °C change in ambient temperature with constant ac line voltage, constant output voltage setting and constant load resistance. Measure temperature coefficient by placing the unit in an oven, varying the temperature over a range within the unit's operating temperature range, and measuring the change in output voltage.
Constant Current (CC) Tests CC Setup. Constant-current tests are analogous to constant-voltage tests, with the unit's output short circuited and the voltage set to full output to assure CC operation. Follow the general setup instructions. Load Effect (Load Regulation). Constant current load effect is the change in dc output current (Io) resulting from a load-resistance change from short-circuit to full-load, or full-load to short-circuit.
0.25Ω (6023A) 2.0Ω (6028A) load resistor that is capable of safely dissipating 250 watts. Proceed as follows: a. Connect the test equipment as shown in Figure 2-8. b. Switch the unit's power on and turn the output voltage all the way up. c. Turn up output current to: 29.0Vdc (6023A) 10Vdc (6028A) Check that the unit's CC LED remains lighted. d. Check that the rms noise current measured by the current probe and rms voltmeter is no more than: 15mA rms (6023A). 5mA rms (6028A) Figure 2-8.
3 Troubleshooting Maintenance described herein is performed with power supplied to the instrument, and protective covers removed. Such maintenance should be performed only by service-trained personnel who are aware of the hazards involved (for example, fire and electrical shock). Where maintenance can be performed without power applied, the power should be removed.
Table 3-1. Control Board Test Connector, A2J7 PIN NO. SIGNAL NAME Vdc Digital-Circuits Bias & Reference Voltages 1 +5V 22 + 20V(5V UNREG) 14 2.5V ref 6 0.5V ref 5.0 20.0 2.50 0.50 Analog-Circuits Bias Voltages 2 + 15V 21 - 15V 15.0 -15.
Electrostatic Protection The following caution outlines important precautions which should be observed when working with static sensitive components in the power supply. This instrument uses components which can be damaged by static charge. Most semiconductors can suffer serious performance degradation as a result of static charges, even though complete failure may not occur. The following precautions should be observed when handling static-sensitive devices. a. b. c. d. e. f.
To avoid the possibility of personal injury, remove the power supply from operation before opening the cabinet. Turn off ac power and disconnect the line cord, load, and remote sense leads before attempting any repair or replacement. When replacing any heatsink-mounted components except thermostat, smear a thin coating of heatsink compound between the component and heatsink. If a mica insulator is used, smear a thin coating of heatsink compound on both sides of the mica insulator.
A4 Power Mesh Board Removal After removing the inside cover, remove the A4 power mesh board by lifting, using the large aluminum heatsink as a handle. Two connectors hold the A4 board at its bottom edge. When installing the A4 power mesh board, lower it vertically into its connectors and press in place. A3 Front-Panel Board Removal Remove the A3 front-panel board by first removing the entire front-panel assembly. You do not need to remove the top cover. Follow this procedure: a.
Table 3-1 gives the signals for each of the test points on the control board test connector. This connector is provided in service kit P/N 06033-60005. The measurements given here include bias and reference voltages as well as power supply status signals and waveform information. Table 3-2 provides troubleshooting information based on the status of the PWM-ON and PWM-OFF signals which drive the PFETs. This table is used for no-output failures.
Main Troubleshooting Setup Figure 3-1 shows the troubleshooting setup for troubleshooting all of the unit except the front-panel and initial no output failures (See page 31). The external power supply provides the unit's internal bus voltage. The ac mains cord connects to the unit's A1T3 bias transformer via an isolation transformer, thereby energizing the bias supplies, but it does not connect to the input rectifier and filter because that would create the bus voltage.
As a convenience in implementing the troubleshooting setup, prepare cord sets as shown in Figure 3-2. This facilitates connecting the unit's input power receptacle to the external supply and connecting the bias transformer to the ac mains. Figure 3-2. Modified Mains Cord Set For Troubleshooting With the mains cord unplugged proceed as follows: a. Remove the top cover and the inside cover as described on page 26. Set switch S4 (front-left corner of the A1 main board) in TEST position.
d. e. With the LINE switch off, connect an external dc supply to the outside prongs of the unit’s power receptacle. Ignore polarity as the unit’s input rectifying diodes steer the dc power to the correct nodes. Complete the setup of Figure 3-1 by attaching an ac mains cord to test points TP1 (L, black wire) and TP2 (N, white wire) and connect the green ground wire to the unit's case ground terminal or a suitably grounded cabinet screw.
Table 3-2.
Troubleshooting Bias Supplies +5V on A2 Control Board. The PWM A2U6 includes a clock generator (45KHz set by A2R53 and A2C26), and a current limit (2Adc set by 0.15Vdc across A2R50). It turns off each output pulse using the difference between the voltage at voltage divider A2R46-A2R47 and the 2.5Vdc set by voltage regulator A2U5. Circuit Included. + 5Vdc bias supply circuitry from connector pin A2P1-15 through jumper A2W3 on A2 control board. Setup. The Main Troubleshooting Setup, page 29.
Table 3 5.
Input: NODE ( + ) A2U4 (IN), A2C16 (-) MEASUREMENT ≈ -24Vdc SOURCE A1U1, AlC1 ( + ) N0DE ( - ) A2U4 (OUT) A2VR2 (anode) A2VR2 (cath.) MEASUREMENT 1.25Vdc 11.7Vdc 2.05Vdc Outputs: NODE ( + ) A2U4 (ADJ) A2VR2 (cath.) A2R33, A2R34 To check if load on -15V is shorted, remove jumper A2W3. Refer to Down Programmer, page 39, for the + 8.9V bias supply, and refer to OVP Circuit, page 39, for the +2.5V bias supply. Power Section Blocks This section contains the blocks referenced in Tables 3-2 and 3-5.
A2U18-13 A2U18-12 A2U18-15 A2U17-8 A2U17-11 DROPOUT A2Q5 (col) (RELAY ENABLE) cycle power cycle power cycle power cycle power cycle power cycle power five 100ms pulses then hi two 200ms pulses then hi transition lo to hi at 800 msec transition lo to hi at 1.0 sec transition lo to hi at 1.1 sec transistion 5.0 to 0.3Vdc at 1.0s Troubleshooting PWM & Clock The inputs to inhibit Gate A2U19A and PWM gate A2U19B are the keys to PWM troubleshooting.
+ OUT + OUT + OUT 40 40 40 10 2 2 short A2J3-4 to A2J3-8 3.8Vdc (OVERRANGE) 2.0Vdc (CV) 0.0Vdc Troubleshooting DC-To-DC Converter Parallel NOR gates A4U2A, A4U2B and A4U1A act as drivers and switch on FETs A4Q3 and A4Q4 through pulse transformer A4T1. NOR gate A4U1B turns off the PFETs through pulse transformer A4T2 and transistors A4Q1 and A4Q2. Circuits Included. On-Pulse Driver, Off-Pulse Driver, PFET Switches and Drivers on A4 power mesh board. Setup. The Main Troubleshooting Setup, page 29.
Troubleshooting CV Circuit V-MON, the output of CV Monitor Amp A2U7, is 1/4 the voltage between + S and - S. CV Error Amp A2U8 compares V-MON to CV PROGRAM. Innerloop Amp A2U10A stabilizes the CV loop with IVS input from A2U10C. The measurements below verify that the operational amplifier circuits provide expected positive and negative dc voltage excursion when the CV loop is open and the power mesh shut down. Circuits Included. Constant Voltage (CV) Circuit and buffer amplifier A2U10C. Setup.
If the failure symptoms include output current oscillation, check if the differentiator circuit is at fault by removing resistor A2R16 (3.3M ohm ). If oscillations stop, the differentiator is probably at fault. Troubleshooting Down Programmer The down programmer decreases the output when either MASTER ENABLE is low or CV ERROR is more negative than about - 6Vdc. Comparator A4U3B triggers down programming when the voltage at A4U3B-5 is less than about 3Vdc.
Figure 3-3.
Outputs: NODE ( - ) = A2J7-4 NODE ( + ) A2U9 (OUT) A2U14-10 A2U14-11 A2J3-13 A2J3-13 A2J3-13 A2J3-13 Note SET VOLTAGE (Vdc) EXTERNAL INTERNAL 10 10 20 10 10 SETUP cycle power MEASUREMENT 2.5Vdc 1.0Vdc 1.5Vdc hi lo lo hi Connecting a test probe to either input of either comparator in the OV Flip flop (pins A2U14-1, 6, 7, 8, 9, 14 or A2U11-13) may cause the flip flop to change states and cause the probed input to be low.
4 Principles of Operation Autoranging Power Autoranging allows the unit to be compact and light weight and yet to deliver a range of output voltage current combinations which otherwise would require the use of more than one supply or a higher rated-power supply. Autoranging is a name for circuitry which automatically makes full power available at all but low rated output voltages and currents.
Figure 4-2.
Control signals flow from right to left with separate circuits for constant-voltage, constant-current and power-limit control. These three control circuits jointly provide the Autoranging characteristic of Figure 4-lB. AC Turn-on Circuits limit inrush current to the input filter and assure transient free turn-on. Internal Bias Supplies provide five bias and two reference voltages to the unit's circuits and provide input signals to the AC Turn-on Circuits. The unit is a flyback switching power supply.
Figure 4-3.
The unit checks that the + 5Vdc bias voltage and the ac mains voltage are within acceptable limits as part of its turn on sequence. When + 5Vdc comes up, the Bias Voltage Detector resets the Overvoltage-Protection circuit, enables the On Pulse Driver for the PFET switches, and with the AC Surge-Dropout Detector starts the 1-Second-Delay circuit. After one second, relay A1K1 bypasses the Inrush-Current Limiting resistor. After 0.
Figure 4-4. PFET Control Signals Timing Diagram Constant-Voltage (CV) Circuit The Constant-Voltage Circuit compares the output voltage to the user-set CV PROGRAM Voltage to produce the CV CONTROL Voltage. Two comparison amplifier loops accomplish the comparison. In the outerloop, CV Error Amplifier A2U8 compares V-MON, a buffered fraction of the sensed output voltage OVS, to the program voltage from the CV Programming Switches to create the CV ERROR Voltage.
Constant-Current (CC) Circuit The Constant-Current Circuit compares the output current to the user-set CC PROGRAM Voltage to produce the CC CONTROL Voltage. As with the CV Circuit, two comparison amplifier loops accomplish the comparison. OCS is the voltage across Current-Monitoring resistor A1R3, and it senses the output current for the outer loop which is the unit's output current.
A2CR24. The A2R113-A2R114 voltage divider sets the maximum CP voltage to + 1.5Vdc and assures that the diode with the lower control voltage will be forward biased when its control voltage is less than + 1.5Vdc. As an illustration of CV-CC selection, suppose the unit is in CV operation and diode A2CR24 is forward biased by a low CV CONTRL Voltage: Then CV sets CP to less than + 1.5Vdc. CV keeps diode A2CR19 reverse biased and prevents CC control until the CC CONTROL Voltage is even lower.
by inhibiting the PWM through the DROPOUT signal from the l-Second-Delay Circuit. Mains Detect signal, which is fullwave-rectified ac from the + 5Vdc secondary of the bias-supplies transformer, senses the ac mains voltage. The Dropout Detector, including comparators A2U20A and A2U20C, operates by enabling a capacitor-timing ramp when Mains-Detect ceases. Comparator A2U20D monitors the amplitude of Mains-Detect to provide ac surge voltage detection.
5 Replaceable Parts Introduction This chapter contains information for ordering replacement parts. Table 5-3 lists parts in alpha-numeric order by reference designators and provides the following information: a. b. c. d. Reference Designators. Refer to Table 5-1. Agilent Model in which the particular part is used. Agilent Part Number. Description. Refer to Table 5-2 for abbreviations. Parts not identified by reference designator are listed at the end of Table 5-3 under Mechanical and/or Miscellaneous.
Ordering Information To order a replacement part, address order or inquiry to your local Agilent Technolgies sales office. Specify the following information for each part: Model, complete serial number, and any option or special modification (J) numbers of the instrument; Agilent part number; circuit reference designator; and description. To order a part not listed in Table 5-3, give a complete description of the part, its function, and its location. Table 5-2.
Table 5-3. A1 Main Board Parts List Ref. Desig.
Table 5-3. A1 Main Board Parts List (continued) Ref. Desig. R8 R9 R10 R11 R12 R14 R15 R15 R17,18 R19 R20,21 R22.
Table 5-4. A2 Control Board Parts List Ref. Desig.
Table 5-4. A2 Control Board Parts List (continued) Ref. Desig.
Table 5-4. A2 Control Board Parts List (continued) Ref. Desig.
Table 5-4. A2 Control Board Parts List (continued) Ref. Desig.
Table 5-4. A2 Control Board Parts List (continued) Ref. Desig.
Table 5-4. A2 Control Board Parts List (continued) Ref. Desig.
Table 5-5. A3 Front-Panel Board Parts List Ref. Desig.
Table 5-5. A3 Front-Panel Board Parts List Ref. Desig.
Table 5-6. A4 Power Mesh Parts List Ref. Desig.
Table 5-6. A4 Power Mesh Parts List (continued) Ref. Desig.
Table 5-7. Other Replacement Assemblies Ref. Desig.
Table 5-7. Other Replacement Assemblies (continued) Ref. Desig.
6 Component Location and Circuit Diagrams This chapter contains component location diagrams, schematics, and other drawings useful for maintenance of the power supply. Included in this section are: a. b. c. Component location illustrations (Figures 6-1 through 6-5), showing the physical location and reference designators of almost all electrical parts. (Components located on the rear panel are easily identified.) Notes (Table 6-1) that apply to all schematic diagrams.
Table 6-1. Schematic Diagram Notes 1. denotes front-panel marking. 2. denotes rear-panel marking. 3. Complete reference designator consists of component reference designator prefixed with assembly number (e.g.: A2R14). 4. Resistor values are in ohms. Unless otherwise noted, resistors are either 1/4W, 5% or 1/8W, 1%. Parts list provides power rating and tolerance for all resistors. 5. Unless otherwise noted, capacitor values are in microfarads. 6. Square p.c.
Table 6-1.
Figure 6-1.
Figure 6-2.
Figure 6-3.
Figure 6-4.
Figure 6-5.
A System Option 002 General Information This option facilitates the operation of the power supply in an automated system. Four major circuit blocks provide: 1 ) remote analog programming of the supply's output by three different control methods; 2) signals indicating the power supply modes and conditions; 3) two different digital methods of remote control; and 4) the outputs of three bias supplies for use with external circuitry.
Table A-1. Specifications, Option 002 Remote Programming Resistance Programming: 0 to 4K ohm provides 0 to maximum rated voltage or current output. Accuracy: @25°C CV: 0.5% + 12mV (6023A) CC: 1.0% + 110mA (6023A) 0.5% + 70mV (6028A) 1.0% + 500mA (6028A) Voltage Programming: 0 to 5V provides 0 to maximum rated voltage or current output. Accuracy: @25°C CV: 0.25% + 12mV (6023A) CC: 0.30% + 110mA (6023A) 0.33% + 70mV (6028A) 0.
Table A-1. Specifications, Option 002 (continued) Voltage Range: +4.75V to 16V Current Drain: 20mA maximum Status Indicator output: Open collector output: Maximum Output Voltage (logic high): + 16V Logic Low output: + 0.4V maximum at 8mA Remote Control (Trip, Reset, Inhibit) Control Isolator Bias Input Voltage Range: +4.75V to 16V Remote Control Inputs ( Remote Trip , Remote Reset ) Remote Inhibit . On State (logic low): Minimum forward current required (If): 1.6mA Isolator forward voltage (Vf) at 1.
Table A-1. Specifications, Option 002 (continued) Pulse Timing Low Bias or AC DROPOUT will go false after 5V supply stabilizes. Bias Supplies DC Output Ratings: (25°C ± 5) No Load to Full Load 104V to 127V line. + 5V ± 3% at 100mA +15V ± 3% at 75mA -15V ± 4% at 75mA Short Circuit Output Current: +5V + 15V -15V 125mA ± 6% 103mA ± 6% 103mA ± 6% PARD (Typical): + 5V + 15V -15V 25mV pk-pk Same Same 1.
Installation When installing the board, perform the following steps: a. Remove the top and inner cover of the power supply as discussed in Section 3 under Repair and Replacement. b. Remove the plate next to the barrier strip on the rear panel of the supply by unscrewing the 2 M3 screws. c. Insert the already prepared 002 board in the slot closest to the right side (looking from the front-panel) of the supply. d. Use the two M3 screws to connect the rear end of the 002 board to the rear panel of the supply.
Figure A-1. Mating Connector Assembly Operation The following paragraphs provide the operating instructions necessary to interface a 002-equipped power supply into an automated system. A brief description of some circuits is also provided.
Figure A-2. 002 Option Rear Panel Connector J3 and Switches A1 and A2. Local/Remote Programming When switching to local/ control, remember to set Front-Panel Voltage and Current Control to safe levels. Local Programming (Figure A-3). The supply can be switched back and forth between remote and local programming while initially checking out a remote programming circuit. For proper operation of local programming, the user must supply the bias voltage (CONTROL ISOLATOR BIAS).
Figure A-3. Accessing Local Programming While In Remote Programming Mode If solid state circuitry is used, connect the Control Isolator Bias to a driver capable of sinking 10mA of current, then connect the driver's output to both of the LOC/REM terminals. Refer to Figure A-3. Either method will enable relays K1 (CV) and K2 (CC) to switch regulation to the front-panel VOLTAGE and CURRENT controls.
Figure A-4. Calculating Value of Series Dropping Resistor Remote Resistance Programming Check switches A1 and A2 on the rear panel, they must be in their correct positions for CV and CC resistance/voltage programming (See Figure A-2). A resistance variable from 0 to 4K ohms can be used to program the output voltage or current from 0 to full scale. To program the output voltage, connect the variable resistance between J3-25 (CV RES/VOLT PROG.) and J3-22 (E COM.).
Figure A-5. Remote Resistance Programming Figure A-6.
Current Programming (Figure A-7). Check switches A1 and A2 on the rear panel, they must be in the correct positions for CV and CC current programming (See Figure A-2). A current sink variable from 0 to 2mA, can be used to program the output voltage or current from 0 to full scale (See Figure A-7). The following paragraph provides a brief circuit description, refer to schematic diagram. Figure A-7.
Output impedance is l0K ohm: the monitoring device input impedance should be at least 1M ohm to limit error to 1% + basic accuracy; 10M ohm to limit error to 0.1% + basic accuracy. The I. MON signal from the mainframe is also brought out through the 002 Option board. A 0 to full scale current-monitor output is available between pins J3-3 (I. MON) and J3-1 (D COMMON). Output impedance is l0K ohms: the monitoring device input impedance should be at least 1M ohm to limit error to 1% + basic accuracy.
Remote Trip. A negative-going edge applied to terminal J3-30 ( REMOTE TRIP ) will shut down the power supply, reducing the output voltage to near zero. For minimum pulse duration and timing considerations with respect to REMOTE RESET , See Table A-1. The following paragraph provides a brief circuit description (See schematic diagram and Figure A-8). A negative going edge at REMOTE TRIP coupled through opto-isolator (U9) causes one-shot U13B to set the TRIP/RESET latch (U5A) low.
Figure A-8. Remote Control Power-On Preset This open collector output line J3-6, provides a logic low pulse ( Power - On - Preset ) to the user that can be used to initialize or delay a system's operation until + 5V Reg. supply has stabilized. The pulse is generated after primary power is turned on and also after resumption of power following momentary ac dropout or conditions in which line voltage drops below approximately 70% of the nominal. See Table Al for Power - On - Preset signal specifications.
on, it causes J3-6 ( Power - On - Preset ) to be low thus, if used, can initialize or delay a customer's system operation. AC Dropout Buffer Circuit This circuit couples, inverts and isolates the DROPOUT signal (received from the A2 Control Board) of status output terminal J3-19 ( DROPOUT ). The dropout signal indicates loss of primary power, momentary AC dropout, or "brownout" conditions where the AC line voltage drops below approximately 70% normal.
If it is necessary to have all the supplies come up simultaneously after a system shutdown, follow this procedure: a. First bring the REMOTE INHIBIT line low. b. Provide a negative-going pulse to the REMOTE RESET . c. After at least one second, return REMOTE INHIBIT to a high level. Figure A-10. System Shutdown Using Bias Supply Output Figure A-10 shows a second method of system shutdown.
Troubleshooting Before attempting to troubleshoot the 002 Option Board, ensure that the fault is with the option itself and not with the main power supply. This can be accomplished by removing the top cover, inside cover and disconnecting the two ribbon cables from the A2 Control board and checking the operation of the main supply. Otherwise troubleshoot the option board as described in the following paragraphs. Removal of the Option Board.
Figure A-11. Troubleshooting Current Programming of CV Mode Figure A-12. Troubleshooting Current Programming of CC Mode Troubleshooting Status Indicators. The test set-up shown in Figure A-13 can be used to check each of the six status indicators. This set-up will temporarily defeat the isolation of the status lines. Before attempting to troubleshoot a status indicator, check for + 5V Bias for proper operation of the opto-couplers.
Figure A-13. Troubleshooting Status Indicators To check CV Mode proceed as follows: a. Using test set-up, Figure A-13, connect to end of 2KΩ resistor to J3-36. b. Turn on power supply. c. Using "Display Setting'' set voltage and current or power supply for 1 volt and 1 amp. d. DVM should read between 0 and 0.4Vdc. e. Turn off power supply and short to output terminals. f. Turn on power supply. g. DVM should read approximately 5Vdc. To check CC Mode proceed as follows: a.
c. d. e. f. a. Turn on power supply. DVM should read approximately 5Vdc. Set voltage and current controls of power supply to maximum. Decrease resistance of electronic load until "UNREGULATED" LED on front-panel lights. DVM should now read between 0 and 0.4Vdc. To check LOW BIAS or AC Dropout proceed as follows: a. Using test set-up, Figure A-13, connect top end of 2KΩ resistor to J3-19. b. Substitute an oscilloscope in place of DVM. Set vertical deflection for 1 volt/div on the DC input. c.
Table A-3. Replacement Parts REF. DESIG. A7 C1,2 C3 C4 C5 C6 C7 C8,9 C10 C11 C12,13 C14 C15 C16 C17,18 C19 C20-22 CR1-4 CR5-10 CR11-14 CR15 CR16,17 CR18,19 CR20 CR21,22 CR23 CR24,25 CR26-29 CR30 K1,2 L1-3 Q1,2 R1-3 R4 R5 R6 R7 R8,9 R10 R11 R12 R13 R14 R15,16 R17 R18 R19 R20,21 MODEL NO. All All All All All All All All All All All All All All All All All All All All All All All All All All All All All All All All All All All All All All All All All All All All All All All All PART NO.
Table A-3. Replacement Parts REF. DESIG. R22 R23 R24 R25,26 R27 R28 R29,30 R31 R32 R33 R34 R35 R36 R37 R38 R39 R40 R41 R42 R43 R44 R45 R46 R47 R48 R49 R50,51 R52,53 R54 R55 R56 R57 S1 U1-3 U4 U5 U6 U6 U7 U7 U8-10 U11 U12 U13 U14 U15 U15 U16 U16 U17,18 100 MODEL NO. All All All All All All All All All All All All All All All All All All All All All All All All All All All All All All All All All All All All 6023A 6028A 6023A 6028A All All All All All 6023A 6028A 6023A 6028A All PART NO.
Table A-3. Replacement Parts REF. DESIG. U19 U19 U20 U20 VR1-8 VR9 VR10 VR11 VR12 VR13 VR14 VR15 VR16 VR17 Z1 A7J3 W1 W2 W3,4 W5,6 MODEL NO. 6023A 6028A 6023A 6028A All All All All All All All All All All All PART NO. 1826-0393 5060-2942 1826-0607 5060-2946 1902-0556 1902-3185 1902-0556 1902-3256 1902-0779 1902-3180 1902-3110 1902-0575 1902-0556 1902-3256 1810-0276 Mechanical DESCRIPTION IC Voltage Reg. IC Voltage Reg. heatsink assy. IC Voltage Reg. IC Voltage Reg. heatsink assy.
Definitions High = more positive Low = less positive Indicator and Qualifier Symbols OR function Polarity indicator, shown outside logic symbol. Any marked input or output is active low; any unmarked input or output is active high. (Dynamic indicator) Any market input is edge-triggered, ie, active during transition between states. any unmarked input is level sensitive. (Schmitt trigger) indicates that hysteresis exists in device.
SCHEMATIC NOTES 1. ALL RESISTORS ARE IN OHMS, ± 5%, 1/4W, UNLESS OTHERWISE INDICATED. 2. ALL CAPACITORS ARE IN MICROFARADS, UNLESS OTHERWISE INDICATED. 3. WHITE SILKSCREENED DOTS ON P. C. BOARDS INDICATE ONE OF THE FOLLOWING: A. PIN 1 OF AN I. C. (EXCEPT FOR U18 SEE NOTE 4 ). B. POSITIVE END OF A POLARIZED CAPACITOR. C. CATHODE OF A DIODE OR THE EMITTER OF A TRANSISTOR. 4. PIN LOCATIONS FOR SEMICONDUCTORS ARE SHOWN BELOW: 5.
1. 2. 3. 4. Schematic Notes W1 in normally open position. W3 & W4 jumpered Relays K1, K2 normally closed S1A and S1B are located at the rear panel Figure A-15.
Figure A-16.
B Backdating Manual backdating describes changes that must be made to this manual for power supplies whose serial numbers are lower than those listed in the title page to this manual. Look in the following table and located your Agilent Model. Then look at each serial number listed for this group. If the serial number of your power supply is prior to any of the serial number(s) listed, perform the change indicated in the Change column. Note that several changes can apply to your supply.
6023A In the parts list for the Chassis Mechanical change the following: FROM TO Cover-top 06023-00020 06023-00002 Cover bottom 06023-00022 06023-00003 Trim top 5041-8803 5040-7203 Trim sides 5001-0540 5001-0440 Front Frame 5021-8417 5021-5817 Feet 5041-8801 5040-7201 Strap Handle Assy 5062-3703 5060-9803 Strap Retain Rear 5041-8820 5041-6820 Strap Retain Front 5041-8819 5041-6819 CHANGE 6 6023A In the parts list for the Appendix A delete resistor R57 .
