User’s Guide Temperature Controller LDT-5525 ILX Lightwave Corporation · P. O. Box 6310 · Bozeman, MT, U.S.A. 59771 · U.S. & Canada: 1-800-459-9459 · International Inquiries: 406-556-2481 · Fax 406-586-9405 ilx.custhelp.com · www.ilxlightwave.
TA B L E O F C O N T E N T S TABLE OF CONTENTS Safety Information and the Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .vii General Safety Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .vii Safety Marking Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viii Comments, Suggestions, and Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TA B L E O F C O N T E N T S SENSOR SELECT Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 TEC Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 TEC Grounding Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 General Operating Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Warm-Up and Environmental Considerations . . . . . . . . . . . . .
TA B L E O F C O N T E N T S Appendix C AD590 and LM335 Sensor Calibration AD590 Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 LM335 Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 One Point Calibration Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Two Point Calibration Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TA B L E O F C O N T E N T S iv LDT-5525
LIST OF FIGURES LIST OF FIGURES Figure 2.1 LDT-5525 Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Figure 2.2 LDT-5525 Back Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Figure 2.3 Back Panel TEC Connector . . . . . . . . . . . . . . . . . . . . . . 13 Figure A.1 Thermistor Resistance vs. Temperature . . . . . . . . . . . . . 28 Figure B.1 Thermistor Temperature Range . . . . . . . . . . . . . . . . . . . 34 Figure C.1 AD590 Nonlinearity . . . . . . . . . . . . . .
LIST OF FIGURES vi LDT-5525
SAFETY AND WARRANTY INFORMATION The Safety and Warranty Information section provides details about cautionary symbols used in the manual, safety markings used on the instrument, and information about the Warranty including Customer Service contact information.
SAFETY SYMBOLS SAFETY SYMBOLS This section describes the safety symbols and classifications. Technical specifications including electrical ratings and weight are included within the manual. See the Table of Contents to locate the specifications and other product information. The following classifications are standard across all ILX Lightwave products: • Indoor use only • Ordinary Protection: This product is NOT protected against the harmful ingress of moisture.
WA R R A N T Y WARRANTY ILX LIGHTWAVE CORPORATION warrants this instrument to be free from defects in material and workmanship for a period of one year from date of shipment. During the warranty period, ILX will repair or replace the unit, at our option, without charge. Limitations This warranty does not apply to fuses, lamps, defects caused by abuse, modifications, or to use of the product for which it was not intended.
WA R R A N T Y Claims for Shipping Damage When you receive the instrument, inspect it immediately for any damage or shortages on the packing list. If the instrument is damaged, file a claim with the carrier. The factory will supply you with a quotation for estimated costs of repair. You must negotiate and settle with the carrier for the amount of damage.
WA R R A N T Y Comments, Suggestions, and Problems To ensure that you get the most out of your ILX Lightwave product, we ask that you direct any product operation or service related questions or comments to ILX Lightwave Customer Support. You may contact us in whatever way is most convenient: Phone . . . . . . . . . . . . . . . . . . . . . . . . . . . (800) 459-9459 or (406) 586-1244 Fax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
WA R R A N T Y in a container with at least 3 inches (7.5 cm) of compressible packaging material on all sides.
CHAPTER 1 INTRODUCTION AND SPECIFICATIONS This manual contains operation and maintenance information for the LDT 5525 Temperature Controller. If you want to get started right away, read Chapter 2, which covers Operation, first. Product Overview The LDT-5525 Temperature Controller is a microprocessor-based, precision thermoelectric temperature controller designed for temperature control of laser diodes, detectors and other temperature sensitive devices.
CHAPTER 1 INTRODUCTION AND SPECIFICATIONS Product Overview Available Options and Accessories Options and accessories available for the LDT-5525 Temperature Controller include the following: DESCRIPTION MODEL NUMBER Single Rack mount kit (enables installation into a standard 19” rack) 134 Dual Rack mount kit (enables installation of two LDT-5525 instruments into a standard 19” rack) 135 Temperature Controlled Laser Diode Mount 4407 Temperature Controlled Laser Diode Mount (available with collimati
INTRODUCTION AND SPECIFICATIONS Specifications CHAPTER 1 Specifications Output1 Output Type Bipolar constant current source Control Algorithm Smart Integrator, Hybrid PI Compliance Voltage 6 Volts at 4 Amps Maximum Current Output 2 4 Amps Maximum Output Power 24 Watts, typical Current Limit Control Range 0 to 4.4 Amps Current Limit Accuracy +50 mA Ripple / Noise3 <1 mA Temperature Control Temperature Range4 -99 to 199.
CHAPTER 1 INTRODUCTION AND SPECIFICATIONS Specifications Thermistor Range (10 µA) 0.0 to 450.0 KΩ Thermistor Range (100 µA) 0.0 to 45.0 KΩ Usable Thermistor Range 25 to 450,000 Ω, typical Thermistor Resistance Resolution (10 µA) 0.1 kΩ Thermistor Resistance Resolution (100 µA) 0.01 kΩ Thermistor Resistance Accuracy +0.05% of FS AD590 Reverse Bias 8 Volts LM335 Bias 0.
INTRODUCTION AND SPECIFICATIONS Specifications CHAPTER 1 General Output Connectors TEC I/O: 15-pin, D-sub Analog Output: BNC Size 3.5” x 7.3” x 12” Weight 8.0 pounds Power Requirements 90 - 125 VAC, 105 - 250 VAC (jumper selectable) at 50-60 Hz Ambient Temperature Range 0 to +40 oC operating -40 to +70 oC storage Humidity < 85% relative humidity, non-condensing Warm-Up 1 hour to rated accuracy Our goal is to make the best laser diode instrumentation available anywhere.
CHAPTER 6 LDT-5525 1 INTRODUCTION AND SPECIFICATIONS Specifications
CHAPTER 2 OPERATION This chapter describes how to install, adjust, and operate the LDT-5525 Temperature Controller. It is divided into sections covering installation, familiarization and adjustment, and normal operating procedures. This chapter also gives an overview of the LDT-5525's front panel features, and it presents a guide to quickly familiarize the user with the front panel operations. Installation procedures and considerations are also covered in this chapter.
CHAPTER 2 OPERATION Power-Up Sequence Power-Up Sequence With the LDT-5525 Series Precision Temperature Controller connected to an AC power source, pressing the POWER switch will supply power to the instrument and start the power up sequence. During the power-up sequence, the following takes place. For about two seconds all indicators light up, and all of the 7-segment displays indicate "8". Then all lamps are turned off for two seconds. Then, the sensor switch position is displayed for two seconds.
OPERATION Introduction to the LDT-5525 Front Panel CHAPTER 2 Adjustments 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.
CHAPTER 2 OPERATION Introduction to the LDT-5525 Front Panel The temperature is limited (via the sensor feedback) to the T LIMIT value. If the sensor reads a temperature which is greater than T LIMIT, the I TE output will be shut off. The GAIN value is used to control the sensor feedback gain, and thus the temperature settling time and overshoot. If the GAIN is set too low (1 is the lowest setting) the TE cooler will take longer to reach the temperature set point.
OPERATION Introduction to the LDT-5525 Front Panel CHAPTER 2 Appendix C contains information on sensor calibration constants for AD590 and LM335 sensors. Since these devices are used over their linear range, the constants C1 and C2 are used in this case to determine a linear approximation of the temperature, rather than the Steinhart-Hart non-linear approximation which applies for thermistors.
CHAPTER 2 OPERATION Back Panel Controls and Connections Analog Output An analog output signal is available at the ANALOG OUTPUT connector (BNC) on the front panel. This signal is a voltage between 0 - 5.0 volts which is proportional to the measurement signal. For example, an analog output signal of 2.5 volts (+0.5 volts) would represent a measurement of 50% of full scale. Sensor Select Switch Chassis Ground Post 15-pin Connector (Current Output Sensor Input) Fan AC Power Entry Module Figure 2.
OPERATION Back Panel Controls and Connections CHAPTER 2 Table 2.1 SENSOR SELECT Switch Positions SWITCH POSITION CODE 100 µA -01- 10 µA -02- LM335 -03- AD590 -04- The 10 µA and 100 µA designations are for the current source level; thermistor sensor type is implied. When using a thermistor, the supply current depends on the thermistor operating temperature range and the required temperature resolution. Guidelines for setting this switch are contained in Appendix B.
CHAPTER 2 OPERATION Back Panel Controls and Connections TEC Grounding Considerations The TEC outputs of the LDT-5525 are isolated from chassis ground, allowing either output terminal to be grounded at the user's option. Note: For the TEC connector, if any one terminal pin is grounded, then no other terminal pin should be grounded. Damage to external unit or temperature controller will occur.
OPERATION General Operating Procedures CHAPTER 2 General Operating Procedures The following sections present some guidelines for operation, as well as some common operating procedures. Warm-Up and Environmental Considerations Operate the LDT-5525 Temperature Controller at an ambient temperature in the range of 0 to +40°C. Storage temperatures should be in the range of -40 to +70°C. To achieve rated accuracy, let the LDT-5525 Temperature Controller warm up for about 1 hour before use.
CHAPTER 2 OPERATION General Operating Procedures Resistance Mode Operation You can operate the LDT-5525 Temperature Controller in several modes, constant current (I TE), constant thermistor resistance (R), or constant temperature (T). This example is for constant resistance (R) mode. a Plug the LDT-5525 Temperature Controller into an AC power source supplying the correct voltage and frequency for your unit (refer to the back panel for the correct ratings).
OPERATION General Operating Procedures CHAPTER 2 an external current booster. A switch or control circuit of the user's own design is required. It is left as an option which the user may or may not employ. Booster Operation The LDT-5525 Temperature Controller may be used to control a booster current source which accepts a control signal of up to +5.0 volts. A booster current source may be required if the LDT-5525 Temperature Controller's +4 A, 24 W output is not adequate to control a thermal load.
CHAPTER 18 LDT-5525 2 OPERATION General Operating Procedures
CHAPTER 3 MAINTENANCE AND TROUBLESHOOTING This chapter describes how to maintain and troubleshoot the LDT-5525 Temperature Controller. Included are sections covering calibration, disassembly, and troubleshooting. THE SERVICE PROCEDURES DESCRIBED IN THIS CHAPTER ARE FOR USE BY QUALIFIED PERSONNEL. POTENTIALLY LETHAL VOLTAGES EXIST WITHIN THE LDT 5525 TEMPERATURE CONTROLLER. TO AVOID ELECTRIC SHOCK, DO NOT PERFORM ANY OF THE PROCEDURES DESCRIBED IN THIS CHAPTER UNLESS YOU ARE QUALIFIED TO DO SO.
CHAPTER 3 MAINTENANCE AND TR OUBLESHOOTING Calibration Overview Recommended Equipment Recommended test equipment for calibrating the LDT-5525 Temperature Controller is listed in Table 3.1. Equipment other than that shown in the table may be used if the specifications meet or exceed those listed. Table 3.1 DESCRIPTION MFG / MODEL SPECIFICATION DMM HP 3457A DC Amps (@ 1.0A): +0.02% Resistance (@ 10Ω): 0.02% 0.1 µA or 0.
MAINTENANCE AND TROUBLESHOOTING Calibration Adjustments CHAPTER 3 Calibration Adjustments There are two calibration adjustments that need to be made for the LDT-5525 Temperature Controller. They are calibration of sensor measurement, and calibration of the ITE current measurement and limit circuits. If a problem arises during calibration which prevents its normal completion, the calibration may be aborted with no ill effects by simply pressing the OUTPUT switch.
CHAPTER 3 MAINTENANCE AND TR OUBLESHOOTING Calibration Adjustments AD590 Sensor Calibration The following procedure is for calibrating the AD590 sensor measurement so that the temperature measurement will be as accurate as possible. This procedure calibrates the current measurement of the AD590. This procedure does not calibrate C1 and C2. For information on calibrating the AD590 sensor, see Appendix C. Calibration may be aborted by pressing the OUTPUT switch.
MAINTENANCE AND TROUBLESHOOTING Calibration Adjustments CHAPTER 3 LM335 Sensor Calibration The following procedure is for calibrating the LM335 sensor measurement so that the temperature measurement will be as accurate as possible. This procedure calibrates the voltage measurement of the LM335. This procedure does not calibrate C1 and C2. For information on calibrating the LM335 sensor, see Appendix C. Calibration may be aborted by pressing the OUTPUT switch.
CHAPTER 3 MAINTENANCE AND TR OUBLESHOOTING Calibration Adjustments ITE Current Calibration The following procedure is for calibrating the ITE constant current source for both polarities of current. During this procedure the ITE current is driven to a series of pre-determined values. When each of these values is reached and is stable, the user enters the actual value of the current, as measured by an external DMM.
MAINTENANCE AND TROUBLESHOOTING Troubleshooting CHAPTER 3 Troubleshooting This section is a guide to troubleshooting the LDT-5525 Temperature Controller. Some of the more common symptoms are listed here, and the appropriate troubleshooting actions are given. We recommend that the user start at the beginning of this guide. Read the symptom descriptions, and follow the steps for the corrective actions which apply.
CHAPTER 3 MAINTENANCE AND TR OUBLESHOOTING Troubleshooting Unable to adjust output or parameter Check the ADJUST ENBL switch; the indicator must be lit for any adjustments to be made Check the MODE or DISPLAY switch; if they do not respond, the unit may be in measurement calibration mode (see Chapter 3); press the OUTPUT switch to abort this mode.
APPENDIX A STEINHART-HART EQUATION Two-terminal thermistors have a nonlinear relationship between temperature and resistance. The resistance verses temperature characteristics for a family of similar thermistors is shown in Figure A.1. It has been found empirically that the resistance versus temperature relationship for most common negative temperature coefficient (NTC) thermistors can be accurately modeled by a polynomial expansion relating the logarithm of resistance to inverse temperature.
CHAPTER A For the LDT-5525, the Steinhart Hart equation has been simplified to a first order polynomial: 1/T = A' + B' * ln R Equation 2 This equation is easier to solve and provides adequate results. Table A.1 also shows that the use of Equation 2 introduces temperature errors of less than 0.3oC over the range -20oC to 50oC, with accuracies of up to 0.06oC over smaller temperature ranges near room temperature2. 1 Resistance of a 10 kW, Dale 1T1002-5 thermistor 2 Constants A' = 0.99 * 10-3, B' = 2.
CHAPTER A Computer Program We have included a computer program called STEIN1 that uses a least squares curve fitting routine to determine the values of C1 and C2. The program is written in IBM's advanced BASICA. You must create a data file for your thermistor that describes the resistance at various temperatures. The temperature verses resistance calibration data can be obtained from the thermistor manufacturer. Enter the resistance at various temperatures as data points into an ASCII file.
CHAPTER A 80 REM * * * * * * * * * * * * * * STEIN1 * * * * * * * * * * * * * * * 90 REM 92 REM Rev: 3 11 87 94 REM T is expressed in Kelvins. 100 REM Least squares fit program to find the thermistor coefficients 110 REM C1 and C2 in the following equation: 120 REM 130 REM 1/T = C1 + C2 * (ln R) 140 REM 200 REM 210 REM Variables: 220 REM 230 REM T[i], R[i] temperature and resistance data values.
CHAPTER A 1155 X(I)=LOG(R(I)) : Y(I)=1/(T(I)+273.15) 1160 PRINT USING H$; I, T(I), R(I) 1170 GOTO 1130 1180 N=I 1 1190 CLOSE 1200 REM **** accumulate sums **** 1205 SX=0 : SY=0 : SXY=0 : SXX=0 1210 FOR I = 1 TO N 1220 SX=SX+X(I) 1230 SY=SY+Y(I) 1240 SXY=SXY+X(I)*Y(I) 1250 SXX=SXX+X(I)*X(I) 1260 NEXT I 1300 REM **** print out results **** 1310 C[2]=(N*SXY SX*SY)/(N*SXX SX*SX) 1320 C[1] = (SY C[2]*SX)/N 1620 PRINT 1630 G$="Key in: C1 1640 P$=" C2" #.## #.
CHAPTER 32 LDT-5525 A
APPENDIX B SENSING CURRENT AND THERMISTOR SELECTION Choosing the right sensing current depends on the range of temperature you want to measure and the resolution you require at the highest measured temperature. To correctly set the SENSOR SELECT switch you must understand how the thermistor and the LDT-5525 Temperature Controller interact, and how temperature range and resolution values are inherent in the nature of thermistors.
CHAPTER B Thermistor Range thermistor inputs of the LDT-5525. The LDT-5525's measurement system will over-range when the input voltage exceeds about 4.5 volts. Figure B.1 graphically shows the lower temperature and upper voltage limits for a typical 10 K thermistor. (A 10 K thermistor has a resistance of 10 kΩ at 25 oC). The practical temperature ranges for a typical 10 K thermistor with the LDT-5525 are given in Table B.2, below.
Thermistor Range CHAPTER B Temperature Resolution You must also consider measurement resolution since the measurement resolution decreases as the thermistor temperature increases. A temperature controller (such as the LDT-5525) has a limited measurement resolution. A temperature change of one degree centigrade will be represented by a greater resistance increase at a lower temperature than at a higher temperature because of the non-linear resistance of the thermistor.
CHAPTER B Thermistor Range generally a good choice for most laser diode applications where high stability is required near room temperatures. Similarly, 10 K thermistors are often a good choice for detector cooling applications where you want to operate at temperatures from -30 oC to room temperature. If you require a different temperature range or the accuracy you need can't be achieved with either switch setting, select another thermistor.
APPENDIX C AD590 AND LM335 SENSOR CALIBRATION The LDT-5525 Temperature Controller uses two constants (C1 and C2) for calibrating linear thermal sensing devices, such as the AD590, and the LM335. C1 is used as the linear or zero offset value, and C2 is used as the slope or gain adjustment. Therefore, C1 should be set to a nominal value of 0, and C2 should be set to a nominal value of 1, when the SENSOR SELECT switch is in the AD590, or LM335 positions.
CHAPTER C Td = C1 + ( C2 * Tn ) - where C1 and C2 are the constants stored by the user in the LDT-5525 Temperature Controller for the AD590. The AD590 measurement is calibrated, at the factory, with C2 = 1 and C1 = 0 (nominal values). The AD590 grades of tolerance vary, but typically this means that without adjusting C1 or C2, the temperature accuracy is +1 oC over its rated operating range. If C1 and C2 are also calibrated, the temperature accuracy is +0.2 oC over its rated operating range.
CHAPTER C The LDT-5525 Temperature Controller uses v to determine the nominal temperature, Tn, by the formula: Tn = ( v / ( 10mV / K ) ) - 273.15 - where Tn is in oC. The temperature, Td, which is displayed by the LDT-5525 Temperature Controller, is first calibrated as follows: Td = C1 + ( C2 * Tn ) - where C1 and C2 are the constants stored by the user in the LDT-5525 Temperature Controller for the LM335.
CHAPTER C One Point Calibration Method This procedure will work for any linear temperature sensor. The accuracy of this procedure depends on the accuracy of the known temperature, externally measured. It is used to determine the zero offset of the device, and it assumes that the gain offset (slope) is known and is correct. 1 Allow the LDT-5525 Temperature Controller to warm up for at least one hour.
CHAPTER C V = (Ta1 - Ta2) / (Td1 - Td2), and U = Ta1 - (Td1 * V) Then C1n and C2n can be determined by the following: C1n = U + (V * C1) and C2n = V * C2 6 06_07 Replace C1 with C1n by selecting the C1 parameter and entering the new C1n value. Replace C2 with C2n by selecting the C2 parameter and entering the new C2n value.
CHAPTER 42 LDT-5525 C
