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February 2009

  Rev 1

1/20

UM0575

User manual

STEVAL- IHT003V1, e-STARTER demonstration board

based on the ACST6 and X02

Introduction

The e-STARTER demonstration board (

Figure 1

) presents an innovative solution, patented 

by STMicroelectronics, to reduce the power losses due to the positive thermal coefficient 
(PTC) resistors in compressor starter circuits.

This solution features an ACST6 device which is used to turn off the PTC current after the 
motor startup. It should be noted that the traditional PTC is still used in the electronic starter 
circuit because it increases safety in case of ACST short-circuit or diode-mode failure (ref. 
EN60335-1).  This solution allows the starter standby losses to be decreased from typically 
2.5 W to 380 mW or 40 mW, respectively for 230 V and 100 V applications.

The e-STARTER operation principle along with detailed schematics are given as well as 
demonstration board performances and the method to adapt the circuit to a dedicated 
compressor.

It should be noted that this board is not a "plug and play" solution. First, the PTC behavior 
has to be checked (especially V

PTC1

 & V

PTC2

 levels as explained in 

Section 3.1

) and then 

the R4 resistor value has to be chosen before using the board with a compressor.

         

Figure 1.

STEVAL- IHT003V1, e-STARTER demonstration board

         

AM010

38

v1

www.st.com

Summary of Contents for STEVAL-IHT003V1

Page 1: ...use it increases safety in case of ACST short circuit or diode mode failure ref EN60335 1 This solution allows the starter standby losses to be decreased from typically 2 5 W to 380 mW or 40 mW respectively for 230 V and 100 V applications The e STARTER operation principle along with detailed schematics are given as well as demonstration board performances and the method to adapt the circuit to a ...

Page 2: ... Schematics 5 1 3 2 ON state 6 2 Board performances 8 2 1 Maximum current 8 2 2 Standby power losses 8 2 3 Fast transient voltages 9 2 4 Surge voltages 9 2 5 Reliability and safety 10 3 Getting started 12 3 1 Voltage level setting 12 3 2 Connections 13 4 Conclusion 14 Appendix A Component layout and printed circuit board 15 Appendix B Bill of material 17 ...

Page 3: ...6 Voltage spikes at zero current 7 Figure 7 PTC turnoff 7 Figure 8 e STARTER maximum current versus conduction time 8 Figure 9 Spurious e STARTER triggering with a 2 kV surge 230 V compressor 10 Figure 10 e STARTER voltage limited to 648 V thanks to the RUN capacitor 2 kV IEC61000 4 5 surge 10 Figure 11 VPTC1 and VPTC2 definitions 12 Figure 12 e STARTER connections 13 Figure 13 e STARTER topside s...

Page 4: ... high power losses approx 2 5 W Figure 2 gives the typical schematics of this application where a run or a start capacitor can be connected in parallel point 1 or in series point 2 respectively with the PTC 1 2 Standard PTC behavior The transition between PTC ON and OFF states brings a voltage increase across this variable resistor Figure 3 and Figure 4 show two oscillograms of the same PTC in two...

Page 5: ...iled in the following sections The traditional PTC resistor has to be connected between the START and the PTC solder pads refer also to Section 3 2 Note The C3 capacitor is not soldered on the breadboards It can be added if one wants to evaluate its impact on board immunity Figure 3 PTC operation no RUN cap compressor OFF time 10 mains 198 V RMS Figure 4 PTC operation with RUN cap compressor OFF t...

Page 6: ...es at each zero current crossing point typically around 40 V as shown in Figure 6 for a 230 V compressor Applying the click test of norm EN55014 the noise duration could last more than 200 ms depending on the type of compressor and PTC The individual spikes last a few hundreds of microseconds and are spaced at intervals of 10 ms so the limits of continuous disturbance are applicable Since the spik...

Page 7: ...trigger T2 so T1 also stays OFF The PTC is then turned off No more current circulates through the PTC thus no power is dissipated in it Figure 7 shows the typical behavior of this circuit The C1 capacitor voltage gives an image of the PTC voltage When its value reaches the DZ1 clamping level 15 V the MOS gate is latched to 15 V The PTC is then turned off refer to the IA ACST6 current waveform Figu...

Page 8: ... RMS current during 3 s worst case of typical 100 V 60 Hz compressors 50 C after an 11 A RMS current during 0 5 s worst case of typical 230 V 50 Hz compressors This ensures that TJ remains below its maximum allowed temperature 125 C even with a 75 C initial temperature Figure 8 gives the maximum repetitive RMS current that the ACST6 7ST can withstand without any heatsink This curve is given for 40...

Page 9: ...W 2 3 Fast transient voltages Immunity tests as described by the IEC 61000 4 4 standard have been performed with the schematics of Figure 5 connected in series with a compressor without a RUN or START capacitor e STARTER spurious triggerings have not been detected with spikes up to 2 kV This high immunity level has been reached thanks to the high dV dt capability of the ACST6 the improved dV dt ca...

Page 10: ...y and safety Reliability tests have been performed with ACST6 7ST samples submitted to a current shape equivalent to an inrush current of 11 A RMS during 0 5 s No parameter evolution of these samples has been detected after 450 000 cycles which is representative of the lifetime of a refrigerator This result demonstrates the excellent capability of these 6 A products even for applications with high...

Page 11: ...se a thin copper track Figure 15 between the start winding terminal and the e STARTER control circuit For example a 130 µm track conducts the 1mA peak current in normal operation but blows if the whole start winding current at least equal to 5 A RMS circulates through it The ACST6 then remains on the entire time the thermostat switch is closed The behavior is the same as a standard PTC without the...

Page 12: ...ture The PTC peak voltages in ON and in OFF state are called VPTC1 and VPTC2 respectively refer to the dashed lines in Figure 11 Then the VPTC OFF level has to be chosen higher than the maximum value of VPTC1 in order to ensure that the ACST6 has indeed been turned on at the beginning The VPTC OFF level also has to be lower than the minimum value of VPTC2 in order to turn off the ACST6 at the end ...

Page 13: ...ecause the board has to be plugged into the mains and because no insulation is used between the mains voltage and the accessible conductive parts 2 There is no insulation varnish on solders Care should be taken when performing measurements for example voltage probes have to be connected only when the line and the power supply voltages are removed The e STARTER has to be connected to a PTC and a co...

Page 14: ...mpressors PTCs The e STARTER allows the designers of cold appliances to upgrade the efficiency class of refrigerators or freezers with a very low cost solution This solution allows the starter standby losses to be decreased from typically 2 5 W to 380 mW or 40 mW respectively for 230 V and 100 V applications The high reliability and immunity of this circuit are ideally suited to the severe require...

Page 15: ... Component layout and printed circuit board Figure 13 and Figure 14 give the layout of the components for the top and the bottom layers respectively Figure 15 gives the copper side of the e STARTER demonstration board Figure 13 e STARTER topside silk screen AM00909v1 ...

Page 16: ...Component layout and printed circuit board UM0575 16 20 Figure 14 e STARTER SMD components layout bottom view Figure 15 e STARTER copper side bottom view dimensions in cm AM00910v1 AM00911v1 ...

Page 17: ...5BA4 3 1 PNP transistor Q1 SOT 23 Philips PMBT2907A 4 1 NPN transistor Q2 SOT 23 Philips PMBT2222A 5 1 N Channel transistor M1 SOT 23 Fairchild MMBF170 6 1 Resistor620 kΩ 1 4 W 1 R1 TH Axial 0207 7 1 Resistor 470 kΩ 1 4 W 1 R2 TH Axial 0207 8 1 Resistor 510 kΩ 1 4 W 1 R3 TH Axial 0207 9 1 Resistor 30 kΩ 1 4 W 1 R4 TH Axial 020 pitch 2 5 10 1 Resistor 10 kΩ 1 4 W 1 R5 TH Axial 0207 11 1 Resistor 0 ...

Page 18: ...000 V 1 A D1 DO214 SMA 20 1 Small signal diode 1N4148 75 V 0 15 A D2 DO 35 21 1 Zener diode DZ1 DO 35 Fairchild Vishay BZX55C 15 Table 1 e STARTER bill of material continued Index Qty Reference Name Package Manufacturer Manufacturer s ordering code orderable part number ...

Page 19: ...UM0575 Revision history 19 20 Revision history Table 2 Document revision history Date Revision Changes 13 Feb 2008 1 Initial release ...

Page 20: ...ANTIES OF MERCHANTABILITY FITNESS FOR A PARTICULAR PURPOSE AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION OR INFRINGEMENT OF ANY PATENT COPYRIGHT OR OTHER INTELLECTUAL PROPERTY RIGHT UNLESS EXPRESSLY APPROVED IN WRITING BY AN AUTHORIZED ST REPRESENTATIVE ST PRODUCTS ARE NOT RECOMMENDED AUTHORIZED OR WARRANTED FOR USE IN MILITARY AIR CRAFT SPACE LIFE SAVING OR LIFE SUSTAINING APPLICATIONS...

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