mtc-20/2s temperature control system
Contents
1. Optional accessories Miniature temperature sensor Subminiature temperature sensor PT 100 temperature sensor Recording chamber ALA DIN connector cable assembly Heated perfusion tube Thermal foil X eps ce caes Eo b gt cup 3 MTC 20 2S System 3 1 System Description The MTC 20 28 temperature control system is designed for heating purposes in electrophysiological experiments The MTC 20 2S system is housed in small desktop cabinet that can be placed close to the microscope with built in power supply and cooling elements for the power devices The system guarantees low noise operation and has special protection features to prevent the preparation from damage The MTC 20 2S incorporates two electronic thermometers for small semiconductor sensors R2252 i e the sensor has a resistance of 2252 Q at 25 C two digital temperature displays XX X C a set point control with digital readout XX X C a PI proportional integral controller with adjustable parameters an output power control unit and a high power output stage DC continuous operation for resistive 1 e heat only loads with electronic protection circuits The power output is short circuit protected the output power is limited electronically Maximal output voltage is approximately 12 V the current is limited to 1 A The system can be connected to the thermistors heating elements in two ways Using separate cables for the sensors and the heating element or U2. XX X C PWR OUT lower position the voltage at the POWER OUTPUT 18 19 is displayed 12 OUTPUT A 10mV C connector BNC connector monitoring the temperature determined by SENSOR A 13 sensitivity LOmV C 13 SENSOR A connector ZEE 8 pole connector for temperature SENSOR A A This connector also provides the POWER OUTPUT 18 19 for the heating unit max 12V DC and 1A for devices with the ALA DIN connector cable assembly e g HPT 2A see www alascience com SENSOR A 14 MODE switch Switch to select the operation modes of the MTC 20 2S Four modes are available SENSOR A the temperature determined by SENSOR A 13 is used for the control system DIRECT the voltage at the POWER OUTPUT 18 19 can be set directly from the DESIRED TEMPERATURE potentiometer 1 0 12 V no control EXT SENSOR EXTERN SENSOR an external thermometer connected to BNC 15 sensitivity ImV C can be used for the controller loop SENSOR B temperature determined by SENSOR B 16 is used as feedback temperature in the controller loop version 2 7 page 7 MTC 20 2S User Manual 15 EXT SENSOR ImV C connector BNC connector to connect external thermometer with a voltage output of ImV C see 14 16 SENSOR B connector 8 pole connector for temperature SENSOR B This connector also provides the POWER OUTPUT 18 19 for the heating unit max 12V DC and 1A for devices with the ALA DI
3. oen reri e PE Dro Fox VeL ER DU To SERE RUN DE DUoR ENDE ERE 13 Ts LIETAT npase cmi Cox pua ee oondtutdibd ute ded cu tutu putes suse e didtniteUs 16 8 Techical DETTO ETT 16 version 2 7 page 2 MTC 20 2S User Manual 1 Safety Regulations VERY IMPORTANT Instruments and components supplied by npi electronic are NOT intended for clinical use or medical purposes e g for diagnosis or treatment of humans or for any other life supporting system npi electronic disclaims any warranties for such purpose Equipment supplied by npi electronic must be operated only by selected trained and adequately instructed personnel For details please consult the GENERAL TERMS OF DELIVERY AND CONDITIONS OF BUSINESS of npi electronic D 71732 Tamm Germany 1 2 3 4 5 6 GENERAL This system is designed for use in scientific laboratories and must be operated by trained staff only General safety regulations for operating electrical devices should be followed AC MAINS CONNECTION While working with the npi systems always adhere to the appropriate safety measures for handling electronic devices Before using any device please read manuals and instructions carefully The device is to be operated only at 115 230 Volt 60 50 Hz AC Please check for appropriate line voltage before connecting any system to mains Always use a three wire line cord and a mains power plug with a protection contact connected to ground protective earth Before
4. opening the cabinet unplug the instrument Unplug the instrument when replacing the fuse or changing line voltage Replace fuse only with an appropriate specified type STATIC ELECTRICITY Electronic equipment is sensitive to static discharges Some devices such as sensor inputs are equipped with very sensitive FET amplifiers which can be damaged by electrostatic charge and must therefore be handled with care Electrostatic discharge can be avoided by touching a grounded metal surface when changing or adjusting sensors Always turn power off when adding or removing modules connecting or disconnecting sensors headstages or other components from the instrument or 19 cabinet TEMPERATURE DRIFT WARM UP TIME All analog electronic systems are sensitive to temperature changes Therefore all electronic instruments containing analog circuits should be used only in a warmed up condition 1 e after internal temperature has reached steady state values In most cases a warm up period of 20 30 minutes is sufficient HANDLING Please protect the device from moisture heat radiation and corrosive chemicals INSTRUMENT COOLING To prevent damage from overheated components adequate airflow around the heat sink in the rear of the instrument must be ensured version 2 7 page 3 MTC 20 2S User Manual 2 MTC 20 2S Components The following items are shipped with the MTC 20 25 system V MITC 20 2S desktop cabinet X Power cord 4X User manual
5. N connector cable assembly SENSOR B e g HPT 2A see www alascience com 17 OUTPUT B 10mV C connector BNC connector monitoring the temperature determined by SENSOR B 16 sensitivity 10mV C Banana jack connectors for the heating unit This output supplies a maximum voltage of 12V DC and a maximum current of 1 A POWER OUTPUT is also available at the SENSOR A 13 and SENSOR B connectors 16 for devices with the ALA DIN cable assembly 3 3 Hear Panel Elements POWER The PWR switch turns on off the power supply 115 230 V AC max 50 W The selector for the line voltage and the connector for the power cord are located on the rear panel of the instrument FUSE Line fuse 0 8 A slow 115 V or 0 4 A slow 230 V It must be replaced only by specified type Please disconnect mains power plug when replacing fuse Caution The instrument may be damaged if the wrong line fuse is installed e g 0 4 A if the MTC 20 2S is operated at 115 V version 2 7 page 8 MTC 20 2S User Manual 3 4 Electronic Control and Protection Circuits CONTROL LOOP The sensor thermometer PI controller output power stage and heating element form a closed loop control system The desired temperature signal is compared with the output signal obtained from the thermometer giving an error signal This signal is amplified in the PI controller and transferred to the output stage where it 1s converted to a high power output signal appli
6. e MAI Instruments for the Life Sciences OPERATING INSTRUCTIONS AND SYSIEM DESCRIPTION FOR THE MTC 20 2S TEMPERATURE CONTROL SYSTEM DESIRED TEMP C COMMAND r EXT SENSOR OUTPUT B POWER OUTPUT INPUT T mV P C VP ImvPc 1OmvPC MAX 1A DC E VERSION 2 7 npi 2006 npi electronic GmbH Hauptstrasse 96 D 71732 Tamm Germany Phone 49 0 7141 9730230 Fax 49 0 7141 9730240 support npielectronic com http www npielectronic com MTC 20 2S User Manual Table of Contents koae ER UT AU ON NS or cin cud e Smet E oM uU tuerit 3 22 MTC 2025 C INNO TT C C DTE 4 Se IVER C2 O25 5 SUC IM Scie seach 4 22 Sy em ES CHIU OM on etu a be usb POMA mM dte S MIDI D PM MEO UD EUM EIE 4 35 2 DESCrpPUON OF the Front Panel t ec e deoram a eue aaepe Qvo Eta daot 5 2 9 Rear Pane Elettentss ec TUR Doo dee d eO MUI Lu ui Sed OS Mu Ui CE DUAL us 8 3 4 Electronic Control and Protection Circuits cccccccsssssssseccececceeeeeesseececceeeeaaesseeeees 9 2 95 Modes of ODOEatIOT iu iei eri n a qa CR e Exe pet bes kd xoa us me Eau bec us 9 Modes Of Operation Overy lew sistance seine ase RI ed MuR 10 3 0 Setting the DESIRED TEMPERA TURE Jd eter e eet cmt nm Eaedem 10 S MN Giro iSi mp eet ne heer een en ee Ee rere 11 5 Connection of the Sensor DIN Connector eeeeeesssssssssseeeeeeeeneeeene nnne nnne 11 6 Operating eurde Tuning procedure ioo
7. ed to the heating element see also Figure 4 ELECTRONIC PROTECTION CIRCUITS Each system is equipped with two protection systems 1 Sensor inputs an electronic shut off function disconnects the output if the sensor is disconnected broken or short circuited 2 Output protection the output current and voltage are limited electronically Important The sensor used for the control must be in good thermal connection with the heating wire If not overheating and damage may occur ALARM circuit The internal thermometer R2252 sensor inputs are protected by the sensor alarm circuit see above If this thermometer is used as input device for the PI controller the ALARM circuit disconnects the power output if the sensor is damaged or not connected This state is indicated by the red ALARM LED If the DIRECT mode or EXT mode is used the ALARM circuit is disabled ACCURACY Measuring accuracy of the internal thermometer is 0 1 C controller accuracy is 0 5 C or better depending on the amount of heated solution 3 5 Modes of Operation The system can be used in the following modes of operation DIRECT mode DIRECT mode no temperature control the MODE switch 14 Figure 1 is set to the DIRECT position The control unit is not active 1 e the output voltage is preset directly at the DESIRED TEMP control 1 Figure 1 With the setting from 25 to 50 the output voltage increases linearly from 5 V to 12 V The ALARM circuit see b
8. elow is disabled in this mode The MTC 20 2S is designed with an unipolar output If a resistive load is used the system can be used for heating purposes in all modes SENSOR and DIRECT version 2 7 page 9 MTC 20 2S User Manual Internal SENSOR mode In this mode the output voltage is controlled by the PI controller PI proportional integral controller system activated The temperature signal which is used for the control unit 1s selected by the MODE switch L4 The SENSOR A or SENSOR B position selects one of the internal thermometers SENSOR A or SENSOR B which use a small semiconductor sensor The measured temperature is shown at the respective digital display unit 2 or 6 Figure 1 respectively XX X C I If no sensor is connected or if the sensor is damaged or short circuited the internal shut off unit disconnects the power output This state 1s indicated by the red ALARM LED 3 or 7 Figure 1 respectively located just above the sensor connectors EXT SENSOR mode This mode can be used to connect an external thermometer The calibration of the external input SENS INPUT BNC 15 Figure 1 is 1 mV C If this option is used the internal ALARM circuit 1s disabled Modes of Operation Overview DIRECT MODE output voltage is set directly by the DESIRED TEMP C control Internal SENSOR mode output voltage 1s controlled by the PI controller using SENSOR A or SENSOR B EXT SENSOR mode output voltage is controlled b
9. ge at POWER OUTPUT COMMAND INPUT BNC connector analog input sensitivity 10 mV C Set value control potentiometer range up to 45 0 C XX X C or 0 100 of output voltage DIRECT mode Temperature OUTPUT A B BNC connector analog outputs sensitivity 10 mV C output impedance 250 POWER OUTPUT 12 V 1A short circuit protected continuous DC Limiter potentiometer for the maximum output voltage with a linear range from 0 100 Control PI proportional integral controller accuracy typically t0 C GAIN potentiometer logarithmic scale range 10 10k INTEGRATION potentiometer logarithmic scale time range 50 ms 20 s Measuring accuracy 0 1 C at 25 C Power requirements 115 230V AC 60 50 Hz fuse 0 8 0 4 A slow Dimensions desktop cabinet 246 mm 260 mm 90 mm version 2 7 page 16
10. l In Figure 5 the time course of temperature regulation of the MTC 20 2S is shown As resistive load a bulb 12V 21W was used The temperature sensor was fixed directly on the bulb and sensor and bulb were wrapped with foam Starting temperature was 27 3 C Starting conditions were LIMITER set to 0 GAIN set to 0 INTEGRATION off temperature C 39 r 37 35 33 31 29 27 25 I I I I I I I I 0 100 200 300 400 500 600 700 800 900 1000 time s Figure 5 Time course of temperature regulation of the MTC 20 2S 1 LIMITER was set to 100 GAIN was set to a low level 2 GAIN was set to a slightly higher value about 1096 of the whole scale 3 INTEGRATION was turned on at a low level version 2 7 page 15 MTC 20 2S User Manual T Literature Kettenmann H and R Grantyn eds Practical Electrophysiological Methods Wiley Liss New York 1992 Froehr F and F Orttenburger Introduction to Electronic Control Engineering Siemens AG Berlin and Munich 1982 8 Technical Data Sensor input for semiconductor 2252 Q at 25 C standard or platinum 100 Q at 0 C accuracy typically 0 1 C at 25 C with electronic protection Sensor input EXT Mode sensitivity 1 mV C ALARM and SHUTOFF disconnects POWER OUTPUT if temperature is below 3 C not connected or broken sensor or above 45 C short circuited sensor Digital displays 3 1 2 digits XX X C temperature of SENSOR A or B or XX X V volta
11. set to SENSOR A 4 GAIN potentiometer Potentiometer logarithmic scale to change the GAIN parameter amplification of the error signal see chapter 3 4 of the temperature controller PI controller range 10 to oo 5 INTEGRATION potentiometer INTEGRATION Potentiometer to set the INTEGRATION parameter time constant of the temperature controller PI controller time range 50 ms 20 s 6 Display B Digital display to indicate the temperature determined by sensor B 16 7 ALARM LED This LED lights if temperature SENSOR B 16 is not connected broken or short circuited The POWER OUTPUT 18 19 shuts down if this LED is on and the MODE switch 14 is set to SENSOR B 8 LIMITER potentiometer LIMITER X ji Potentiometer to set the voltage range of the POWER OUTPUT 1 19 239 100 12 Volt 9 HEAT LED This LED indicates the status of the POWER OUTPUT 18 19 LED on heating version 2 7 page 6 MTC 20 2S User Manual BNC connector to set the working temperature of the controller system by an external voltage signal This input is scaled with the factor 10mV C 11 SENSOR A SETPOINT PWR OUT switch display mode switch Switch to select the mode of display A 2 SENSOR A upper position the temperature determined by SENSOR A 13 is displayed XX X C SETPOINT middle position the value preset at the DESIRED TEMPERATURE potentiometer 1 is displayed
12. sing the ALA DIN cable assembly that connects both sensors and heating elements A large variety of sensors and thermal elements are available see also Optional accessories in chapter 2 Please contact npi for details version 2 7 page 4 MTC 20 2S User Manual 3 2 Description of the Front Panel DESIRED TEMAS SEHSCNT A SETPOWT 14 IQ 11 2 13 15 16 17 U8 19 Figure 1 MTC 20 25 front panel view In the following description of the front panel elements each element has a number that 1s related to that in Figure 1 The number is followed by the name in uppercase letters written on the front panel and the type of the element in lowercase letters Then a short description of the element is given 1 DESIRED TEMP C potentiometer DESIRED TEMPAT Potentiometer to set the working temperature of the controller system If the display mode switch 11 is in position SETPOINT the preset value is monitored on display A 2 Range 25 C 50 C 2 Display A Digital display to indicate the DESIRED TEMPERATURE the temperature determined by SENSOR A or the voltage at the POWER OUTPUT connectors 18 19 The function is selected by the display mode switch 11 version 2 7 page 5 MTC 20 2S User Manual 3 ALARM LED This LED lights if temperature SENSOR A 13 is not connected broken or short EET circuited The POWER OUTPUT 18 19 shuts down if this LED is on and the MODE switch 14 is
13. system can be grounded either via a BNC cable connected to INPUT or OUTPUT 10 mV C or via the blue OUTPUT GND connector 5 Connection of the Sensor DIN Connector Temperature sensor for PIC MIC TC amm distance red yellow blue white Sensor LE s i gt shield silicone B pole plug snield fabric tape Pin 2 blue white Pin 1 red yellow Figure 2 How to connect the temperature sensor non DIN cable 1 SENS IN 2 SENS IN 3 SENS IN 4 nc 5 nc 6 nc T Power 8 Power Figure 3 Connector pinout of the DIN connector pins 1 and 3 are connected internally version 2 7 page 11 MTC 20 2S User Manual 3173H E Inaina 31x 3H E t3 Od SEMEN SE aasssa OSNAS 1X3 KOSIN3S HAMS JJO v HhOSNAS H3 Od ASLAN SS sewo enjpirediua Yum v p F jejeuuouuejad NIV re AL eedem NOI BON ALOS Sun JOULNOO 3elnIvelddiWal ligit JN YAHOO FIN LACS 0381830 Figure 4 Block diagram of the MTC 20 2S page 12 version 2 7 MTC 20 2S User Manual 6 Operating guide Tuning procedure After unpacking the instrument please check the appropriate voltage at the voltage selector at the back panel Also check that the sensor used for the control is in good thermal connection with the heating wire Important Make sure that the SENSOR or the external SENSOR respectively and the heating device
14. that is controlled by this SENSOR are using the same channel Otherwise the heating device may be damaged due to overheating In the following it is assumed that you use heating devices delivered by npi or ALA Scientific Instruments with 12V operating voltage Please follow these instructions step by step to avoid problems in adjusting the instrument e Turn all potentiometers to the most left position e switch the MODE selector to the position SENSOR A or B depending on which sensor is used as feedback temperature in the controller loop e set the DESIRED TEMPERATURE to e g 37 C DESIRED TEMP C 35 37 40 e turn on the MTC 20 2S and wait at least 15 minutes to warm up the instrument The temperature display should show the actual temperature at the sensor e turn the LIMITER to 100 LIMITER 50 96 0 100 96 Note If you use heating wires with 6V operating voltage turn the LIMITER to 50 to protect the wire from damage If the difference between the actual and the desired temperature is more than 10 C the HEAT LED will light up slightly e turn the GAIN to a position as shown below GAIN 10 0 0 version 2 7 page 13 MTC 20 2S User Manual The actual temperature at the sensor now approaches the desired temperature but will not reach 37 C because the control loop is not yet well adjusted The actual temperature should arrest at 1 to 2 C below the desired temperature Please wait until this stead
15. y state value is reached This may last several minutes If this value is not reached set the GAIN to higher levels until in this example 35 C to 35 5 C is reached If you don t get a steady state value set the LIMITER to 80 90 or 30 40 respectively and wait again Now turn on the INTEGRATION and set it to a low level INTEGRATION OFF MAX The actual temperature at the sensor will now reach the desired temperature possibly after a small overshoot Wait again until the steady state value 1s reached e If the desired temperature is not reached first set the GAIN to a slightly higher level and then if necessary raise the INTEGRATION Note The speed of the control circuit and therefore the time in which the actual temperature reaches the DESIRED TEMPERATURE is highly dependent on the first settings of GAIN and INTEGRATION Thus when beginning to use the MTC 20 2S we recommend to try out several first settings of GAIN and INTEGRATION to find out which settings are best for your experimental conditions If you use a perfusion system it is recommended to heat the solution approximately to the desired temperature before perfusing the bath either with a heating foil wrapped around the supplying tube available from npi or by heating up the supplying bowl As mentioned above it is very important that the sensor element and the heating element are in good thermal connection version 2 7 page 14 MTC 20 2S User Manua
16. y the PI controller using an external thermometer POWER OUTPUT is always available at POWER OUTPUT SENSOR A and SENSOR B 3 6 Setting the DESIRED TEMPERATURE There are two ways to set the DESIRED TEMPERATURE 1 The easiest way is to use the potentiometer DESIRED TEMP C The temperature can be set with this potentiometer from 25 0 C to 45 0 C If the MTC 20 leaves this temperature window the internal shut off unit disconnects the power output This could be the case 1f the sensor 1s broken or short circuited 2 If the user wants to have external control e g with a computer system or to set the temperature to lower 25 C values the DESIRED TEMPERATURE can be set using the COMMAND INPUT 10mV C connector 10 Figure 1 The COMMAND INPUT is scaled 10mV C 1 e 370 mV at this connector would set the DESIRED TEMPERATURE to 37 C Important The set value of the temperature is always the sum of the setting at DESIRED TEMP C potentiometer and the voltage at COMMAND INPUT 10mV C connector 1 e if DESIRED TEMP C is set to 25 0 C and the voltage at COMMAND INPUT 10mV C 1s 150 mV the temperature will be set to 40 C version 2 7 page 10 MTC 20 2S User Manual 4 Grounding To avoid ground loops the internal ground of the system is floating 1 e it is not connected to the protective earth of the mains while the cabinet 1s always connected to protective earth green yellow wire The
Download Pdf Manuals
Related Search