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A-1

APPENDIX

SERVICE  INFORMATION

Figure A-1. Block Diagram

PRINCIPLES OF OPERATION 

Throughout this discussion, refer to both the block diagram of Figure A-1
and the schematic diagram at the rear of the manual. The input AC line
voltage is stepped down by the power transformer and applied to the recti-
fier and filter. The rectifier-filter converts the AC input to raw DC which is
fed to the positive output terminal via parallel series regulator(Q1 and Q3)
and current sampling resistor(R2). The regulator, part of the feedback loop,
is made to alter its conduction to maintain a constant output voltage or cur-
rent.  The  voltage  developed  across  the  current  sampling  resistor  is  the
input  to  the  constant  current  error  amplifier.  The  constant  voltage  error
amplifier obtains its input by sampling the output voltage of the supply. 

Any  changes  in  output  voltage  or  current  are  detected,  amplified  by  the
error amplifier and driver and applied to the series regulator in the correct
phase and amplitude to counteract the change in output voltage or current. 

Two error amplifiers are included in a CV/CC supply, one for control-
ling output voltage, the other for controlling output current. Since the
constant  voltage  amplifier  tends  to  achieve  zero  output  impedance
and alters the output current whenever the load resistance changes,
while the constant  current amplifier causes  the output impedance to
be  infinite  and  changes  the  output  voltage  in  response  to  any  load
resistance change, it is obvious that the two amplifiers can not oper-
ate simultaneously. For any given value of load resistance, the power
supply must act either as a constant voltage source or as a constant

current source - it can not be both; transfer between these two modes
is accomplished at a value of load resistance equal to the ratio of the
output voltage control setting to the output current control setting. 

The  reference  and  bias  circuit  provides  stable  reference  voltages  which
are used by the constant voltage/current error amplifier circuits for compar-
ison purpose. The digital meter circuit provides an indication of output volt-
age and current for constant voltage or constant current operating modes. 

The display power circuit provides voltage which is used by A/D con-
verter and LED drive. 

Diode CR3 is connected across the output terminals in reverse polar-
ity. It protects the output electrolytic capacitor and the series regulator
transistor from the effects of s reverse voltage applied across the out-
put terminals. 

PERFORMANCE TEST 

The following provides the test procedure in high current range for verifying
the unit's compliance with the specifications and characteristics of Table in
page 1-3. The same test procedure may be applied to low current range. 

Test Equipment Required 

The following Table lists the equipment required to perform the tests
and  adjustments.  You can separately  identify the equipment for per-
formance tests, or calibration in the USE column of the Table.

Summary of Contents for E361 A Series

Page 1: ...ent E3611A Agilent E3612A Manual Part No 5959 5304 April 2000 Edition 5 0 1 233 41 50604 7 86 943 896 01 2 3 45 3 86 77 896 3 6 0 7 8 3 4 9 4 5 9 0 9 04 896 4 2 01 4 9 4 0 7 8 2 0 04 2 0 8 6 2 A B 24 4 947 6 8 0 C 6 C 04 6 8 04 8 0 86 943 896 D E D F D G D G D G D G D G D G D H D H D H D H D H D I D I D I 1 1 ...

Page 2: ... avoid injuries always disconnect power dis charge circuits and remove external voltage sources before touching components SAFETY SYMBOLS Instruction manual symbol the product will be marked with this symbol when it is necessary for the user to refer to the instruction manual Indicate earth ground terminal The WARNING sign denotes a hazard It calls attention to a proce dure practice or the like wh...

Page 3: ...rift for 8 hours after an initial warm up of 30 min utes Constant Current Less than 0 1 plus 10 mA total drift for 8 hours after an initial warm up of 30 min utes METER ACCURACY 0 5 2 counts at 25 C 5 C OVERLOAD PROTECTION A continuously acting constant current circuit protects the power supply for all overloads including a direct short placed across the terminals The constant voltage circuit limi...

Page 4: ...lude e brief description of the problem The Turn On Checkout Procedure in this manual can be used as an incoming inspection check to verify that the sup ply is operational See the appendix for tests that verify the supply s specifications Location And Cooling Figure 1 shows the outline shape and dimensions of the unit It is shipped ready for bench operation after connection to an ac power source T...

Page 5: ...current operation proceed as follows a Turn CURRENT control fully counter clockwise to ensure that output decreases to 0 A and than turn on power sup ply b Adjust VOLTAGE control no load connected for maxi mum output voltage allowable voltage limit as deter mined by load conditions During actual operation if a load change causes the voltage limit to be exceeded the power supply will automatically ...

Page 6: ...t duration during constant voltage operation Any capacitance added externally will improve the pulse current capability but will decrease the safety provided by the current limiting circuit A high current pulse may damage load components before the average output current is Iarge enough to cause the current limiting circuit to operate Reverse Current Loading Active loads connected to the power sup...

Page 7: ...mpedance to be infinite and changes the output voltage in response to any load resistance change it is obvious that the two amplifiers can not oper ate simultaneously For any given value of load resistance the power supply must act either as a constant voltage source or as a constant current source it can not be both transfer between these two modes is accomplished at a value of load resistance eq...

Page 8: ... Off mode f When the reading settles record the output voltage again Check that the two recorded readings differ no more than 0 01 of output voltage plus 2 mV Figure A 2 Basic Test Setup Source Effect Line Regulation Definition Source effect is the change in dc output voltage when the ac input voltage changes from a minimum to maximum value 10 of nominal voltage Test Parameter Measured Variable Ou...

Page 9: ... output voltage to the full rated value d Set the electronic load to transient operation mode between one half of unit s full rated value and unit s full rated value at a 1 KHz rate with 50 duty cycle e Set the oscilloscope for ac coupling internal sync and lock on either the positive or negative load transient f Adjust the oscilloscope to display transients as in Figure A 3 g Check that the pulse...

Page 10: ...urn the unit s power on and turn VOLTAGE control fully clock wise c Turn up output current to the full rated value Check that the AMPS display reads full rated values and CC indicator remains lighted Reduce CURRENT control if not lighted d Record the voltage across Rs and convert it to current through dividing by Rs e Operate the electronic load in short input short mode f When the reading settles...

Page 11: ...ak voltage across Rs and convert it to cur rent through dividing by Rs Check that the peak to peak noise current is no more than 1 mA Figure A 6 RMS Measurement Test setup CALIBRATION PROCEDURE To calibrate ammeter and full scale current connect test equipments as shown in Figure A 7 Figure A 7 Calibration in High Current Range Calibration in High Current Range a Turn VOLTAGE and CURRENT control f...

Page 12: ...AC120 0E 7 7 2 3 B 8 8 30 AC120 0E 7 7 C34 3 B 8 8 30 AC120 0E 8 7 7 2 B 3 B 8 8 30 AC120 0E 7 7 2 3 B 8 88 30 AC120 0E 7 7 C34 3 B 8 8 30 AC120 0E 8 7 7 2 B 3 B 8 30 AC120 0E 7 7 2 3 B 8 30 AC120 0E 7 7 7B 77 F C A6 1 7 7 8 0 5 0A CC CC 4 C 7 7 8 C 92A 0 0 03 7 7 7B 77 C A6 1 7 7 8 7 3 0 C2 4 0 6 7 7 8 8 B C90 95 F 7 7 8 92AA 9320 9 2 0 7 7 C34D2 B 1 1 C 8 A34 7 7 2 1 8BB 1 C 8 7 7 8 5 3 C A 4 9 ...

Page 13: ... 2 0 4 5 7 6 7 5 5 0 649 80 2 8 0 4 5 6 7 0 649 80 2 8 0 6 5 649 0 2 8 0 4 5 6 5 649 2 8 0 4 5 6 5 649 58 2 8 0 4 5 6 0 A 46 64 B C 4 5 7 6 0 649 58 2 8 0 4 5 6 0 649 58 2 8 0 6 7 5 649 02 6 7 0 649 6 2 0 4 5 6 5 649 8 2 8 0 4 5 6 5 5 649 08 2 8 0 4 5 6 5 649 8 0 2 8 0 4 5 6 5 0 649 0 2 8 0 4 5 6 5 0 649 5 2 8 0 4 5 6 07 5 5 649 85 02 0 4 5 6 07 5 649 8 02 0 4 5 6 07 5 5 649 2 6 5 0 649 5 2 8 0 6 ...

Page 14: ...4 2 D 8 22 C 022 2343 5 0 5 2 4 E F 7D 9 7 2343 5 6 2 4 3 E F 7D 9 2343 5 2 2 4 E F 7D 9 2343 2 2 DC C D9A 2343 2 3 4 7 89A 2343 4 352 G 97 G 2343 5 5 3 B G 97 9 2343 5 5 3 B G 97 9 2343 5 2 5 2 3 B G 97 9 2343 3 1 2 8 22 C 022 2343 5 2 B89A89C 76 A 2343 5 2 2 B89A89C 76B 2343 5 2 B89A89C 76C 9 2343 4 352 9 B 2343 2 44 9D7 0 AB 2343 5 5 5 0 1234 34 2343 5 5 5 0 1233 34 2343 5 2 5 2 5 0 1235 34 234...

Page 15: ...566 641 4 0 4 6 4 0 24 4 0 561 4 0 79 4 0 56 367 47 8 4 8 6 8 562 0 5 0 5 0 5 56936A 2 4 0 516 4 0 51131 6 47 4 0 517 6A 6 8 6 8 B13 CD05 8 D 0 9 8 8 5 5 8 8 5 5 8 5 5 E 8 0 0 F 0 DG 40HI JKLMI NO KLL PNQRNSIST EQKUVIW KUI XHNYS ZS THI K NJI PNQRNSIST JKLMI TK LI4 4 LL UIXZXTNUX KUI 4 3 3 KSW NHQX3 MSLIXX NTHIUYZXI XRIPZOZIW4 64 LL PKRKPZTNUX KUI QZPUNOKUKWX3 MSLIXX NTHIUYZXI XRIPZOZIW4 14D D 0 XY...

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Page 17: ... initial purchase are included in Agilent s product price only if Customer pays Agilent international prices defined as destination local currency price or U S or Geneva Export price If Agilent is unable within a reasonable time to repair or replace any product to condition as warranted the Customer shall be entitled to a refund of the purchase price upon return of the product to Agilent The warra...

Page 18: ...rdingly Conforms with the following product standards The product herewith complies with the requirements of the EMC Directive 89 336 EEC including 93 68 EEC and carries the CE Marking accordingly European Union As detailed in Electromagnetic Compatibility EMC Certificate of Conformance No TCF CC TCF 00 102 based on Technical Construction File TCF No ANJ12 dated 20 12 2000 EMC Assessed by Celestic...

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