STEVAL-ILD004V1: leading-edge dimmer
Contents
1. 1597 WI life augmented User manual STEVAL ILD004V1 leading edge dimmer Introduction The purpose of this board is to propose an innovative and low cost power topology using two sensitive SCRs and a single IGBT to dim all kind of lamps 100 240 V halogen lamps SELV halogen lamps through magnetic or electronic transformers and the new CFL and LED dimmable lamps The main features of this dimmer are e Operation for 2 wire wall dimmer e Leading edge control only compatible with all lamps commonly found on the shelves e Operation on 110 V or 230 V line rms voltage and 50 Hz or 60 Hz line frequency e Dimmable power range note higher power is possible with larger heatsink 3 to 600 W for 230 V rms line 3 to 300 W for 110 V rms line power efficiency 230 V gt 99 standby losses 230 V 0 3 W e Short circuit protection at startup e Enhanced interface with pushbuttons soft start and soft stop memory of last setting e Compliance with EMC standards Compliant with EN55015 for European market Criteria A for 2 kV IEC 61000 4 5 surge for fast transients above 2 5 kV according to IEC 61000 4 4 This document describes the principle and operating conditions of this demonstration board The performance of this board is described regarding power losses and EMC standard test results The description of the user interface and connections will help users to setup and evaluate this dimmer Figure 1 STEVA2. Date Revision Changes 19 Dec 2012 1 Initial release Update schematic and BOM 04 Mar 2013 2 Add figures for voltage surges dimmer withstanding Add appendix for heatsink design and schematic with L C filter 06 Nov 2014 3 Content reworked to improve readability 26 27 DoclD024045 Rev UM1597 IMPORTANT NOTICE PLEASE READ CAREFULLY STMicroelectronics NV and its subsidiaries ST reserve the right to make changes corrections enhancements modifications and improvements to ST products and or to this document at any time without notice Purchasers should obtain the latest relevant information on ST products before placing orders ST products are sold pursuant to ST s terms and conditions of sale in place at the time of order acknowledgement Purchasers are solely responsible for the choice selection and use of ST products and ST assumes no liability for application assistance or the design of Purchasers products No license express or implied to any intellectual property right is granted by ST herein Resale of ST products with provisions different from the information set forth herein shall void any warranty granted by ST for such product ST and the ST logo are trademarks of ST All other product or service names are the property of their respective owners Information in this document supersedes and replaces information previously supplied in any prior versions of this document
3. 2014 STMicroelectronics All rights reserved 4 DoclD024045 Rev 27 27
4. Na 0 E 0 79 E 9 0285 VOVSNI amp 900 saa 19 amp gg 3 E no d o Simia Nos 558 T za 819 darang e L06zNzo 598 0 T 5 dog9 20 nee 919 76 M SIr HANS gad OL vH m L ad Dt t TANG 010 Ha aa eld n 01158 ii pa ot ow 5 2 i SiO nee eo LAG x 691559 x96 eH junys 1891 YO 1 902851 VOPSNI o io LZ b oszsa p vr ZOONI lt 44 qunys Wa er DoclD024045 Rev 18 27 UM1597 Board layout and silkscreen Appendix Board layout and silkscreen Figure 13 Component layout Ly DoclD024045 Rev 3 19 27 Bill of materials UM1597 Appendix C Bill of materials Table 2 Bill of material BOM Reference Part C1 tu C2 C10 100n C3 C5 C6 C7 C8 C12 10n C4 C17 C18 in C9 100 25V C11 15u 63V C13 15n C14 680p C15 10n C16 4 7n 63 V D1 D2 1N5404 D3 D4 MRA4007 D6 BZV55C15 D7 D8 D9 D11 D12 D13 D14 D1N4148 D15 5 6V zener diode D10 BZT55B13 D5 LED F1 Thermal cut off shunt J1 CON2 J2 4 EMI inductor shunt J4 IGBT shunt J5 J6 J7 J8 J9 J10 PT L1 2 20 01 02 TS820 600FP Q3 STGF10NC60KD Q4 BS250 Q5
5. blue SCR1 SCR2 IGBT ON OFF 3 3 Safety instruction Warning The high voltage levels used to operate the SCR dimmer evaluation board could present a serious electrical shock hazard This evaluation board must be used in a suitable laboratory by qualified personnel only familiar with the installation use and maintenance of electrical power systems The STEVAL ILD004V1 evaluation board is designed for demonstration purposes only and shall not be used either for domestic installation or for industrial installation 4 14 27 DoclD024045 Rev 3 UM1597 Getting started 3 4 Test procedure and test points Follow this procedure to use the STEVAL ILD004V1 board 1 Connect one lamp terminal to one of J1 header terminal T1 or T2 as shown on Figure 10 2 Connect the other lamp terminal and the other J1 terminal to a powered off mains plug 3 Putthe mains voltage on 4 Press the on button to switch the lamp on Take care to use a non conductive tool to press each pushbutton to avoid any contact with live parts which are under line voltage 5 Press and P buttons always with a non conductive tool to change the lamp brightness Using certain connectors Figure 11 itis possible to measure several electrical signals e IGBT IGBT gate command MCU output e SCHR1 and SCR2 respectively Q1 and Q2 gate commands MCU output e Vcg IGBT collector terminal to measure collector emitter voltage if voltage probe is c
6. by the varistor which clamps the dimmer voltage to 600 V equal to maximum non repetitive surge off state voltage allowed for the SCR and the IGBT On the second case the dimmer is in ON state when the 2 kV voltage surge is applied Thanks to the high over current capability of the TS820 600FP the 8 20 us current surge is absorbed by the SCR without any damage even after have applied 10 times 2 kV positive surges and 10 times 2 kV negative positive Figure 9 IEC 61000 4 5 board performance o max 28 3 A Vr 200 V div t 5 4 Moy 50 div Va 100 V div Ch2 200V Mi 0gs Chi 7 4 TV Ch2 100V M50 0us Ch3 1 52V Ch3 5 005 500mv Dimmer OFF SCR amp IGBT remain OFF Dimmer ON SCR sustains the 8 20 current surge 4 12 27 DoclD024045 Rev UM1597 Getting started 3 Getting started 3 1 Board connection and options Figure 10 shows the connection diagram of the board please refer to Section 3 3 before performing any test e Header J1 is used to connect the dimmer to the mains in series with the lamp Terminals 1 or T2 can either be connected to the load or directly to the mains A Appropriate connection of the lamp to mains neutral or line will depend on electrical safety regulations Usually the lamp has to be connected to neutral e J2 connector is a 4 pin connector used to connect an MCU programmer example STM8S Discover
7. design directives incandescent lamps are being progressively banished from European and American markets Low consumption lamps like CFL and LED are being used more and more But halogen lamps are still on the picture for high power starting at 100 W and for G9 and R7s bases New dimmers have then to be compliant with a wide range of lamp technologies This board is a two wire dimmer i e only two wires are required one connected to the load and another back to the line Operation principle The simplified schematic of the board is shown on Figure 2 Using two sensitive SCRs T1 and T2 with very low triggering gate current 200 pA for TS820 600FP allows a DC gate current to be applied Then each SCR can remain on even if the lamp current is zero as the gate is supplied up to the end of the line half cycle This avoids light flicker The two SCRs are placed in back to back connection with a common Cathode in order to have a single circuit to control both devices A diode is added in reverse parallel with each SCR For positive mains half cycle T1 and D2 are conducting For negative mains half cycle T2 and D1 are conducting An IGBT M placed in the diode bridge D1 D2 D3 and D4 is used to slow down the current rising edge at dimmer turn on and then to reduce the conducted electromagnetic noise This IGBT avoids the use of a bulky EMI filter capacitor inductor which could cause slight acoustic noise Figure 2 STEVA
8. nter lacus da KE dex Pees EE EK 14 3 3 Safety instruction 14 3 4 Test procedure and test points 15 3 5 Possible changes 15 3 6 ISSUS SOWING 16 4 CONGIUSION 2 pa a KARGA ERREUR RENE AER EU aa DER RR RR dew 17 Appendix A lt 1 18 2 27 DoclD024045 Rev 3 1597 Contents Appendix Board layout and 19 Appendix Bill of 20 Appendix D Dimmer phase angle table 22 Appendix E Power losses and temperatures for a 300 W 110 V load 23 Appendix F Heatsink design exemple 11 C W 24 Appendix G Dimmer schematic without IGBT L C filter values given for 300 W 120 V 25 REVISION XX pasan NENG KG DAA GG KAKA kk sd WA bak eas 26 0024045 Rev 3 3 27 Operation principle and targeted application UM1597 1 1 1 2 4 27 Operation principle and targeted application Dimmer for CFL LED and halogen lamps The targeted application of this board is the wall dimmer for domestic or industrial use able to dim all kind of lamps without any light flicker With recent ecological
9. L ILD004V1 board November 2014 DoclD024045 Rev 1 27 www st com Contents UM1597 Contents COME Si ccc ctu eee nen eee 2 1 Operation principle and targeted application 4 1 1 Dimmer for CFL LED and halogen lamps 4 1 2 4 13 Selected 5 1 3 4 Silicon controlled rectifier SCR 5 1 3 2 cg 5 1 3 3 Microcontroller unit 6 14 Operating conditions 22254085552 tA E 6 2 Board performances 7 2 1 Soft start and SOIE BIDD ized ER XR xxx wes ex RS 7 22 and LED operation 7 2 3 Conducted noise 8 24 Short circuit protection 8 2 5 IMMUNITY oo eee PP PE ETT E IER 9 2 6 Power losses 10 2 7 Standby IOSSES 2252523054 akian ka En ATING ha 11 2 8 Voltage surges 12 3 Getting started o iui ioca dtc e KR RC aet eee 13 3 1 Board connection and options 13 3 2 User
10. L ILD004V1 simplified schematic Mains voltage DoclD024045 Rev 3 ky UM1597 Operation principle and targeted application 1 3 1 3 1 1 3 2 4 The switch command sequence is shown on Figure 3 The IGBT is first switched on to control the current rising edge After 300 us the SCR is switched on to reduce the on state forward voltage drop of the dimmer and then the conduction power losses are decreased A 2 2 UH inductor L is added in series with both SCRs to slow down the current variation due to this voltage drop dip which occurs when the current switches from the IGBT to the SCR Figure 3 Switch command sequence 500 W 230 V Halogen lamp Chi toov 500V M2 50ms lines 4 8V E 00 V qu 7 007 M50 0us Chi X 77 9V 500mAQ 1 0040 Ch4 5 007 4 5 00V Selected components Silicon controlled rectifier SCR One of the main characteristics of the SCR for this application is its low gate current TS820 600FP features a maximum of 200 pA Using the TO220 full pack insulated package ensures just one heatsink can be used for both SCRs TS820 600FP main characteristics are e Oncstate rms current 8 A up to a 91 case temperature e Repetitive peak off state voltage 600 V e repetitive surge peak on state current for a 10 ms pulse 70 IGBT A 10 A 600 V IGBT the STGF10NC60KD is used
11. Q10 BS170 Q6 MOSFET N STD1NK60 Q7 Q9 Q11 2N2222A ZTX Q8 Q12 Q2N2907 Q13 Q14 BSS159N 20 27 DoclD024045 Rev 3 UM1597 Bill of materials 4 Table 2 Bill of material BOM continued Reference Part RV1 VARISTOR S20K250 R1 R2 R10 R27 22k R3 36k R16 20k R4 R12 R25 10 Ohm R5 R6 220k 350 V 0 6W R7 R8 R17 200k RQ 1 Ohm R11 R14 R19 10k R13 330k R15 5k R18 1k R20 21 51 Ohm R22 0 05 Ohm 0 5 W R23 100 R26 7 5k R28 3k SW1 SW2 SW3 SW_PB_SPST U1 STM8S103F2 U2 LD2981ABU50 DoclD024045 Rev 21 27 Dimmer phase angle table UM1597 Appendix Dimmer phase angle table 22 27 Table 3 Dimmer phase angles Angle number Angle 50 Hz delay ms 60 Hz delay ms 1 36 2 1 7 2 45 2 5 2 2 3 54 3 2 6 4 63 3 5 3 0 5 72 4 3 5 6 81 4 5 3 9 7 90 5 4 3 8 99 5 5 4 8 9 108 6 5 2 10 117 6 5 5 6 11 126 7 6 1 12 135 7 5 6 5 13 144 8 6 9 DoclD024045 Rev Power losses and temperatures for 300 W 110 V load Appendix Power losses and temperatures for a 300 W 110 V load Figure 15 shows the different power losses measured with a 300 W 110 V halogen lamp with the same IGBT gate circuit designed to fulfill EN55015 standard see Section 2 3 Conducted noise Figure 15 Power losses for a 300 W 110 V halogen lamp Power losses W 5 0
12. Total losses 4 5 Conduction losses 4 0 Switching losses 3 5 3 0 2 5 2 0 1 5 1 0 0 5 Dimmer turn on delay ms 0 0 2 2 5 3 3 5 4 4 5 5 5 5 6 6 5 7 Maximum power losses are reached for the maximum conduction time and are equal to 4 7 W These power losses are then slightly higher than those measured for the 600 W 230 V load 4 5 W Tests similar to those in Section 2 6 Power losses could be performed in a closed box environment The junction temperatures of both the SCR and the IGBT will here again remain below the maximum allowed limits It should be noted that for the North American market compliance to EN55015 is not mandatory Then the IGBT gate resistance R3 or capacitor C16 could be reduced to reduce the switching losses It should be noted that setting these values to a too low value could produce acoustic noise due to the mechanical oscillations of the tungsten lamp filaments DoclD024045 Rev 23 27 Heatsink design exemple Ry 11 C W UM1597 Appendix F Heatsink design exemple 11 C W 24 27 Figure 16 gives the package outline of the heatsink used in our STEVAL ILD004V1 board The heatsink made with a 1 mm thick aluminium plate Its thermal resistor is typically 11 C W Figure 16 dimensions are give in millimeters Figure 16 Heatsink design exemple Warning two different Drills diameter 3 2 mm or D 5 5 mm DoclD024045 Rev 3 1597 D
13. as 57 C is measured at the bottom Values measured for a 110 V rms line voltage are given in Appendix E Standby losses Standby losses are mainly due to the MCU consumption For the STM8S103F2 using the halt mode low comsumption MCU mode the maximum current consumption at 125 C is 105 uA cf SMT8S datasheet The quiescent current of the 5 V voltage regulator U2 has also to be taken into account typically 100 The dimmer standby losses for a 0 2 mA power supply output current is 0 29 W at 230 V rms This dimmer is not concerned under standby directives as the board does not feature any display or any sensor to automatically exit from the standby mode the wake up is initiated by the end users when they push a button DoclD024045 Rev 11 27 Board performances UM1597 2 8 Voltage surges Thanks to a S20K250 varistor RV1 the board is immune against voltage surges up to 2 kV when the dimmer is in the off state When the dimmer is in the on state the SCR features a high current capability which makes it able to withstand a surge current coming from a 2 kV surge as described in the IEC 61000 4 5 standard Following figures show the dimmer behavior in case of voltage surges For this test a 2 kV voltage surge is applied on the peak mains voltage The dimmer is placed in series with a 600 W 230 V halogen lamp For Figure 9 left side the dimmer is in OFF state The 2 kV surge energy is absorbed
14. for current commutations This IGBT is also in full pack to have the same non insulating heatsink for this IGBT and the two SCRs STGF10NC60KD main features are e Lower on voltage drop Veg sat 1 8 V typ For lc 5 A and T 125 C e Lower ratio for better noise immunity Short circuit time up to 10 us supported DoclD024045 Rev 5 27 Operation principle and targeted application UM1597 1 3 3 1 4 6 27 Microcontroller unit MCU The STM8S103F2 has been chosen as it fits very well with the light dimmer application requirements Its main features are 16 MHz advanced STM8 core with Harvard architecture and 3 stage pipeline Program memory 8 Kbyte Flash Data memory 640 bytes true data EEPROM RAM 1 Kbyte Up to 17 l Os on a TSSOP 20 pin package including 12 high sink outputs 16 bit general purpose timer with 3 CAPCOM channels IC OC or PWM 8 bit basic timer with 8 bit pre scaler Operating conditions This board is designed to drive all kind of lamps for a wide range of applications Power mains rms voltage 21096 100 120 V 220 240 V Frequency 50 Hz or 60 Hz Ambient temperature 0 to 60 closed box operation allowed refer to Section 2 6 Supported loads Power range from 3 W to 600 W for a 230 V rms mains voltage 300 W max for 110 V Dimmable compact fluorescent lamps Dimmable LED lamps Incandescent lamps Halogen lamps Electronic dimmable trans
15. formers Magnetic transformers 4 DoclD024045 Rev UM1597 Board performances 2 2 1 2 2 4 Board performances Soft start and soft stop For an enhanced smart control a soft start and a soft stop are implemented in software This means that at the dimmer power on or power off respectively the light increases until the last set power level or 50 in case of 1 utilization or decreases until lamp light off This on off control is activated when the on off pushbutton is pressed more than 100 ms Dimmer soft start or soft stop consists of automatically setting up every turn on angle in the register table to the previously set value Each step is set during 200 ms For example at the first dimmer plug in 7 steps are needed to reach the mid power The soft start lasts then 1 4 second Programmed dimmer phase angle list is given in Appendix D for 50 and 60 Hz line frequencies CFL and LED operation For low consumption lamps the main issue of dimmers today is the required minimum current to keep the power switch on and to avoid lamp flickering Thanks to the DC gate control of the TS820 the lamp current can reach zero and the SCR remains latched as previously explained An example is shown Figure 4 with an 8 W dimmable LED lamp where the lamp current clearly goes to zero without causing any issue The use of SCR for the current conduction contrary to MOS gate device allows good operation with inductive l
16. immer schematic without IGBT L C filter values given for 300 W 120 V dimmer Appendix Dimmer schematic without IGBT L C filter values given for 300 W 120 V dimmer Figure 17 Dimmer schematic 5 5 m ot 8 28 as a m amp Sr 55 R l 5 25 z 88 5 WMS 5 z m 55 E 25 Or E g now zb sk 588 28 ag RS 599 88 88 o 5 5 5 5 a sal 52 8 2 8 a deo i x l 5 mH 1SYN E E VISUN 5 288 9 5 ng aaa KE ae o e e ala z al amp o E z 2 89 5 oe OND ox 5 E 8 8 gt 32 ao b gt a Es 58 8 w X 3 28 a MW m 3 228 2 En N MS 8 5 2 sue a Sa R Byz 2 a 5 5 85 8 ES 83 a 35 AT Ki 8 8 22 i i rge s3 B az 4 gt I 4 o2 j 5 os tI 25 2o Or B E a we 8 Ix E t t LAW pi 4 KO i z 5 8 I 5 sun 98 ak 2 8 4 DoclD024045 Rev 25 27 Revision history UM1597 Revision history Table 4 Document revision history
17. o C17 which charges both N MOS gates to a negative voltage when I O pin is pulled down to zero DoclD024045 Rev 9 27 Board performances UM1597 2 6 10 27 Figure 7 SCR gate circuit for dV dt withstanding improvement Qi TS820 600 BSS159N Q13 5V C17 22k BSS159N Q14 Q2 TS820 600 This gate circuit also helps to withstand fast transient voltages as described in the IEC 61000 4 4 standard The X2 capacitor and a specific reset software routine which allows previous configuration restoration on or off status set power level allow high levels to be supported Table 1 gives the board minimum supported levels according to the IEC 61000 4 4 test conditions for the different coupling modes Table 1 IEC61000 4 4 board minimum level supported levels Line coupling L N Burst polarities 5 kHz 4kV 3 3 kV 2 7 kV 3 2 kV 100 kHz 3 kV 2 7 kV 2 6 kV 2 8 kV IEC 61000 4 4 test conditions are e Load is a 50 230 V halogen lamp e The minimum withstood burst level given in Table 1 is the maximum burst voltage applied for 1 minute without any lamp light on e Mains voltage is 230 V rms 50 Hz e 5kHZz or 100 kHz burst frequency e Board at 10 cm from the reference plane The dimmer is able to withstand up to 2 6 kV for the worst case which is above the 2 kV required by the standard for home appliances Power losses Total power los
18. oads and also in case several lamps are used in parallel The board can dim lamps between 36 to 144 which is equivalent to 2 ms to 8 ms for a 50 Hz line frequency see Appendix D of the mains cycle That induces a light brightness variation from 5 to 9095 of the nominal power of the lamp Figure 4 8 W LED lamp dimming VGK Cni toov 5 00V Chi X 150V 200mAQ Ch4 5 00V DoclD024045 Rev 7 27 Board performances UM1597 2 3 2 4 8 27 Conducted noise EMC directives have to be fulfilled for appliances sold in the European market This dimmer has then in particular to fulfill the EN55015 standard This standard defines the maximum levels of the conducted noise due to mains current switching To limit this noise the IGBT gate circuit refer to R3 and C16 in board schematic on Appendix A is designed to reduce the rising edge of the mains current Figure 5 illustrates the EMI noise measured according to EN55015 for the maximum Switched current i e for the maximum load power a 600 W 230 V halogen lamp dimmed at a 5 5 ms turn on angle 50 Hz line frequency Figure 5 EN55015 standard validation 600 W 230 V halogen lamp dimmed at 5 5 ms 120 Conducted noise dBpyV 100 Qpeak Average Qpeak limit Average limit 80 60 40 20 F MHz 0 001 0 01 0 1 1 10 100 Short circuit protection To avoid adding a fu
19. onnected to GND e Voc DC power supply voltage for IGBT gate drive 12 V e GND board control reference all previous voltages must be measured referenced to this GND connector Please note that the STEVAL ILD004V1 board is not insulated from the mains voltage All test or measurement equipment has then to be insulated from the mains to avoid line short circuit though this equipment ground circuit Also as soon as a measurement ground is connected to the board the equipment ground can be connected to the line voltage and could cause user electrical shock if proper test procedures are not applied 3 5 Possible changes 4 The following changes can be applied by the end user if needed e Implement an EMI filter instead of IGBT for EMC conducted noise fulfillment The board schematic of such a dimmer will then be greatly simplified refer to Appendix G To evaluate this solution you have to follow this procedure Using strap 2 an inductor can be added and the C15 X2 capacitor can be changed For example for 300 W US dimmer a 29 uH inductor and a 100 nF capacitor can be used For 500 W European dimmer 2 4 mH inductor and 100 nF capacitor can be used to fulfill EN55015 standard Strap 3 must be removed in this case to disconnect the IGBT collector e IGBT gate resistor used to control the turn on speed can be changed for a different losses noise trade off This can be done if a different load power than 600 W 230 V is targeted
20. or if EN55015 has not to be fulfilled If J2 connector is used to upload the MCU software the board has to be disconnected from the mains before connecting the programmer DoclD024045 Rev 15 27 Getting started UM1597 3 6 16 27 Issue solving If the LED is lit and if the board does not answer to pushbutton pressure this means a short circuit has been detected You need to restart the dimmer Disconnect it from the mains wait few minutes to let the Vpp level 5 V decrease below at least 2 5 V and reconnect it with a new load before restarting the dimmer 4 DoclD024045 Rev UM1597 Conclusion 4 Conclusion The STEVAL ILD004V1 demonstration board allow designers to implement a leading edge light dimmer which will be directly compliant with market requirements These requirements are e Dim all kind of dimmable lamps without any problem From to 600 W 230 V power loads or 300 W for 110 V A Halogen CFL LED and transformer magnetic or electronic e Compliant with European EMC standards EN55015 Limits and methods of measurement of radio disturbance characteristics of electrical lighting and similar equipment EC61000 4 4 Testing and measurement techniques electrical fast transient burst immunity test EC61000 4 5 Testing and measurement techniques surge immunity test e Smart interface Soft start and soft stop Setting memory Protection agains
21. se and then cause any issue in case the end user has to replace it the board is self protected against a short circuit event This can occur if the dimmer is wrongly connected The protection is achieved with a shunt resistor R22 used to detect an overcurrent A hardware protection with transistors Q11 and Q12 is implemented to turn off the IGBT quickly The short circuit information is also sent to the MCU through port In case of a short circuit detection the MCU does not turn the SCRs on An IGBT turn on trial is performed at the next half cycle If the current detected by R22 is still above the defined limit here 12 5 A as it is the current required to reach 0 6 V through the 0 047 ohm R22 resistor and if this happens for four consecutive trials the board is then definitely turned off A green LED D5 informs the user that a short circuit has been detected The only way to restart the board is to disconnect it from the power mains and plug it back after few minutes DoclD024045 Rev 3 ky UM1597 Board performances 2 5 4 Figure 6 shows the overcurrent protection in the case of triggering at peak line voltage ona short circuited load with a 264 V mains rms voltage i e 240 V 10 It should be noted that thanks to the soft start procedure the initial turn on normally occurs only for 170 turn on delay This means that the voltage across the dimmer should be below 50 V instead of 380 V as on the
22. ses are split into IGBT turn on switching losses and SCR conduction losses Figure 8 shows the different power losses measured with a 600 W 230 V halogen lamp which is the worst case and with the IGBT gate circuit which allows EN55015 to be fulfilled as shown on Figure 5 DoclD024045 Rev 3 ky UM1597 Board performances 2 7 Note 4 Figure 8 Power losses for a 600 W 230 V halogen lamp Power losses W 5 0 Total losses 4 5 Conduction losses 4 0 Switching losses 3 5 3 0 2 5 2 0 1 5 1 0 0 5 Dimmer turn on delay ms 0 0 2 3 4 5 6 7 8 Maximum power losses are reached for the maximum conduction time and are lower than 4 5 W We have performed tests in a closed box environment with limited heat transfer capability Then as the heatsink is put vertically as it is traditionally mounted in a wall dimmer application its aluminum heatsink maximum length 58 mm area 3076 thickness 1 mm presents an 11 C W thermal resistor refer to Appendix F The heatsink maximum temperature in steady state i e after more than 8 hours of continuous operation reaches 108 C for the maximum conduction time This gives a maximum junction temperature of respectively 113 C for the TS820 and lower than 111 C for the STGF10NC60KD The maximum average ambient temperature is then slightly higher than 60 C 67 is measured inside the box at the top where
23. t load short circuit due to connection error DoclD024045 Rev 17 27 UM1597 Dimmer schematic Appendix Dimmer schematic Figure 12 Dimmer schematic GSPG0110D11515 0 05 78 gi T Sid kO 00 c 2 ANN T E NG Ne 0 p VezzzNz 18 60 9 TE 1899179 T 1062NZO 72 an Li e 0 1545 Sd Ms 1546 Sd Ms 1585 Sd Ms ems zMS IMS 1 ni uo o to 9 i uoi A LT so PT so NGA am opt 5 0 an 50 EL 98 Ki o g fat tod _ IP veezenz vod NG Su S yg o 9 9 op 498 wd te Fe wimsitad s Wd 9H Nd wise NIMS zad 904 S d E NG x S d ES ELS SAd Pa SNO s 24015818 gt t a za x ASL 14 Ajddng S 924 0 am T T Br 4 2009 HOMO BULBUL ISIN v zr sa
24. test shown on Figure 6 The IGBT thermal stress is then greatly reduced in normal short circuit operation Note that a load short circuit occurs usually in case of mistaken connection This means that the overcurrent protection will work at first turn on i e for a 170 turn on delay In case of lamp flash over which can occur at the end of life of incandescent lamps the short circuit occurs during dimmer conduction The SCRs are then on and will sustain the flash over current Indeed this current is equivalent to a mains short circuit So typically around 250 A peak but lasts typically only 1 ms The current stress is thus equivalent to 31 A s which is well below the specified l t of the TS820 45 5 Figure 6 Short circuit overcurrent protection behavior Chi S0 0V 200v 50 085 Ch3 2 00 AQ 316v Immunity At board plug in a fast voltage transient can be applied to the semiconductor switch and can exceed the SCR dV dt capability This is not a major issue for an SCR that will then turn on safely and will not be damaged as long as the load current is below the SCR maximum current capability To avoid the SCR turn on sensitive SCR dV dt support can be greatly improved when its gate is short circuited to its cathode For this purpose a normally on N MOS is connected between each SCR gate and cathode terminals refer to Q13 and Q14 on Figure 7 These MOS devices are turned off thanks t
25. y Kit for software upload or inboard debugging e Several straps allow the user to add some optional components Strap 1 this strap can be used to add a thermal fuse Strap 2 this strap can be replaced by an inductor in case an EMI passive filter is preferred to an IGBT IGBT Q3 has then to be disconnected by removing strap 3 for EMI evaluation and C15 input capacitor should be increased especially if compliance to EN55105 is expected Strap 3 this must be removed to disconnect the IGBT as explained just above Figure 10 Board connection diagram Mains voltage Programmer connector DoclD024045 Rev 13 27 Getting started UM1597 3 2 User interface Figure 11 shows user interface pushbuttons and measurement points e ON OFF pushbutton this button is used to turn on or turn off the dimmer e pushbutton a short pressure gt 100 ms for 50 Hz operation on this button produces an increase of lamp light of one step A longer pressure allows changing the power level continuously e P pushbutton a short pressure gt 100 ms for 50 Hz operation on this button produces a decrease of lamp light of one step A longer pressure allows changing the power level continuously SCLED when on this LED indicates that a short circuit has been detected four times consecutively The whole board will remain off up to line disconnection and plug back Figure 11 User interface and test points in
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