Agilent Technologies E3615A, E3614A, E3617A, E3616A service manual Current Monitoring

Page 43

 

 

Figure 6

 

Set the CC switch down, and all others up.

 

Iin = 1/A x Iout

 

 

 

 

Iout = A x Vin

 

 

 

 

Where

Iout is the power supply output current in amps.

 

Iin is the programming current in μamps.

 

A is the gain.

 

 

 

 

 

 

 

Model

 

A (A/μA)

1/A (μV/A)

 

 

 

 

 

 

E3614A

 

0.055

18

 

 

 

 

 

 

E3515A

 

0.0278

35.9

 

 

 

 

 

 

E3616A

 

0.0158

63.4

 

 

 

 

 

 

E3617A

 

0.00928

108

 

 

 

 

 

Programming currents can be increased by adding a resistor across the CC+ and CC-. A 10 volts drop across R1 represents full scale current of the power supply. When a 1 kohm resistor is added across R1, the programming currents are as follows with the programming current in mA.

Model

A (A/mV)

1/A (mA/A)

Parallel resistor required for a

1 amp/mamp value of A (kohm)

 

 

 

 

 

 

 

E3614A

0.594

1.69

1.7

 

 

 

 

E3515A

0.297

3.37

3.45

 

 

 

 

E3616A

0.168

5.95

6.28

 

 

 

 

E3617A

0.0989

1.01

11.2

 

 

 

 

Current Monitoring

Current of the power supply can be monitored across the internal current monitoring resistor. One side of the resistor is at the +output and A3; the other side of the resistor is at A1. The table below shows the resistor value and conversion factors. To obtain the current divide the measured voltage by the resistor value or multiply the amps/V times the voltage measured.

 

Model

Resistor

amps/V

 

 

value (Ω)

 

 

 

 

 

 

 

E3614A

0.1

10

 

 

 

 

 

 

 

E3515A

0.2

5

 

 

 

 

 

 

 

E3616A

0.6

1.67

 

 

 

 

 

 

 

E3617A

0.89

1.12

 

 

 

 

 

 

 

 

 

 

 

1-10-5

Image 43
Contents April Agilent E361xA 60W Bench Series DC Power SuppliesSafety Summary Operating Instructions General Information Line Fuse Operating Temperature RangeMeter Programming Resolution Temperature CoefficientInitial Inspection InstallationInstallation Data Input Power RequirementsPower Cord TURN-ON Checkout ProcedureOperating Instructions Operation Beyond Rated Output Local Operating ModeConnecting Loads Operating ModesRemote Voltage Sensing Remote Operating ModesRemote Analog Voltage Programming Normal Parallel Operation MULTIPLE-SUPPLY OperationAUTO-PARALLEL Operation Gramming according to the remote-programming instructions Normal Series OperationTotal output voltage to ground must not exceed 240 Vdc AUTO-SERIES Operation= slave output voltage AUTO-TRACKING OperatonLoad Considerations Service Information Test Equipment Required MaintenanceOperation Verification Tests Performance Tests Type Required Characteristics USE Recommended ModelMeasurement Techniques Load Transient Response Time Constant Voltage CV TestsLoad Regulation Load Effect Line Regulation Source EffectPardrms Measurement PARDRipple and NoisePARDPeak-to-Peak Measurement CV Drift Stability Constant Current CC TestsCC Drift Stability Adjustment and Calibration ProcedureRegulating Loop Troubles TroubleshootingOverall Troubleshooting Procedure Reference and Bias CircuitOvervoltage Protection Circuit Troubles Symptom Checks and Probable CausesStep Action Response Probable Cause Step Measure Response Probable Cause Replaceable Parts Table A-10. Replaceable Parts List Table A-10. Replaceable Parts List Contd R28,111 0698-3228 Resistor 49.9K +-1% .125W TF TC=0+-100 RESISTOR-VAR 10K +-10% ALL IC V RGLTR-FXD-POS 4.8/5.2V TO-220 PKG ALL DIODE-GEN PRP 180V 200MA DO-35 ALL Table A-11. Component Value Model Page Page Page Page Manual Supplement T E Constant Voltage ModeProgramming Voltage Common to the Minus Output Alternative Voltage Programming Using ResistorsProgramming Voltage Common to the Minus Output Constant Current with Voltage Programming Constant Current ModeCurrent Monitoring Remote Resistor Programming, Constant Voltage Remote Resistor Programming ConnectionsRemote Resistor Programming, Constant Current Certification Declaration of Conformity