Lightwave Communications LDT-5525 manual Adjustments

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O P E R A T I O N

Introduction to the LDT-5525 Front Panel

Adjustments

C H A P T E R 2

The ADJUST section contains the Adjust knob for entering values, and it contains the ENBL (adjust enable) switch and indicator. In order to make any adjustment, the ENBL indicator must be lit. Pressing the ENBL switch toggles the ENBL indicator on or off.

Display

The display is used to show measurements, output set point, and parameter set points. Whenever a set point is being displayed, the VIEW SET indicator will be lit.

The DISPLAY switch is used to select the measured current (I TE), temperature, resistance, or the set point value. The set point type is determined by the MODE selection. Repeatedly pressing the DISPLAY switch will cycle the display from ITE to temperature to resistance (with thermistor sensors only) to set point and back to ITE, and so on.

When in I TE mode, the set point will be TE current.

When in R mode, the set point will be thermistor resistance in KΩ. R mode is not available if the back panel SENSOR SELECT switch is set to LM335 or AD590. R mode operation may offer improved set point resolution (over T mode), depending on the desired temperature set point.

Note: The resistance set point is NOT maintained if the control mode is changed

(e. g. from R mode to T mode). Also, if the SENSOR SELECT switch is moved from 10 µA to 100 µA while in R mode, the resistance set point will be rounded to match the display resolution.

When in T mode the set point will be temperature in oC.

When the output is off and a measurement is displayed, if the adjust knob is turned the control mode set point will be displayed for three seconds. If the set point is adjusted (by turning the adjust knob) the set point timer will be restarted. Therefore, three seconds after the set point is adjusted the display will return to the last measurement.

Parameters

The LDT-5525 Temperature Controller allows adjustment of the following parameters, I LIMIT (TE current limit), T LIMIT (temperature limit) and GAIN (sensor feedback amplifier gain). In addition, the sensor calibration values may be entered.

The LDT-5525 will limit the I TE output to the I LIMIT value, regardless of the set point or control mode.

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LDT-5525

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Contents User’s Guide Page Table of Contents Appendix a Steinhart-Hart Equation Appendix C AD590 and LM335 Sensor Calibration Iv LDT-5525 List of Figures Vi LDT-5525 General Safety Considerations Safety Information and the ManualSafety Marking Symbols Safety SymbolsWarranty Claims for Shipping Damage When you contact us, please have the following information Comments, Suggestions, and ProblemsXii LDT-5525 Product Overview Introduction and SpecificationsDescription Model Number Available Options and AccessoriesOutput1 SpecificationsUser Calibration General Specifications LDT-5525 Rack Mounting AC Power ConsiderationsOperation Introduction to the LDT-5525 Front Panel Power-Up SequenceAdjustments Sensor CAL Output Back Panel Controls and Connections Sensor Select SwitchBack Panel TEC Connector TEC ConnectorTEC Grounding Considerations Warm-Up and Environmental Considerations General Operating ProceduresTemperature Mode Operation External Safety Switch Operation Resistance Mode OperationBooster Operation General Operating Procedures LDT-5525 Calibration Overview Maintenance and TroubleshootingWarm Up Recommended EquipmentEnvironmental Conditions Thermistor Calibration Calibration AdjustmentsAD590 Sensor Calibration LM335 Sensor Calibration ITE Current Calibration Symptom Causes and Corrective Actions TroubleshootingTemperature, based on C1 and C2 Table A.1 Comparison of Curve Fitting Equations STEINHART-HART EquationThermistor R/T Curves Computer Program REM Print Using H$ I, TI, RI LDT-5525 Thermistor Range Sensing Current Thermistor SelectionTable B.2 10K Thermistor Temperature Range Selecting the Sensing Current Temperature ResolutionSelecting and Using Thermistors Thermistor Range AD590 Sensor AD590 and LM335 Sensor CalibrationFigure C.1 AD590 Nonlinearity LM335 Sensor0607 Two Point Calibration Method One Point Calibration MethodC1n = U + V * C1 and C2n = V * C2 LDT-5525