Tender for performing An investigation into the EMC ... EMC Services Ltd (YES) at the University of York is currently performing a study into the EMC emissions from Switched Mode Power

Chris Clegg

Radiocommunications Agency AY4398 8230CR1

© York EMC Services Ltd Page 2 of 26 Issue1

LIST OF TERMS AND ABBREVIATIONS 3

1 INTRODUCTION 4

1.1 Objectives of the overall study 4

2 CIRCUIT DIAGRAMS OF THE ITEMS PURCHASED FOR THIS SUDY 5

2.1 Introduction 5

2.2 Circuit diagram of the EUTs 5 2.2.1 Item 1: Circuit diagram for the Mass produced SMPS for a PC 5 2.2.1 Item 2: Replacement PC SMPS 7 2.2.3 Item 3: DVD player SMPS 9 2.2.4 Item 4: Sky Digital Box SMPS 11 2.2.5 Item 5: Printer SMPS 13 2.2.6 Item 6: Plug-in SMPS 15 2.2.7 Item 7: One way rotary dimmer SELC 17 2.2.8 Item 8: Power corded hammer drill SELC 19 2.2.9 Item 9: Separate speed transformer SELC 21 2.2.10 Item 10: Courtesy wall light SELC 23

3 CONCLUSIONS 25

4 REFERENCES 26



List of Terms and Abbreviations

CENELEC Comité Européen de Normalisation Electrotechnique

CISPR Comité International Spécial des Perturbations Radioélectriques

COTS Commercial Off The Shelf

DIY Do It Yourself

EMC Electromagnetic Compatibility

EMI Electromagnetic Interference

EUT Equipment Under Test

IEC International Electrotechnical Commission

ITT Invitation To Tender

MOSFET Metal-Oxide Semiconductor Field-Effect Transistor OATS Open Area Test Site

PC Personal Computer

RA Radiocommunications Agency

RF Radio Frequency

RTCG Radio Technology and Compatibility Group

SELCs Switched Electronic Load Controllers

SMPSs Switched Mode Power Supplies

YES York EMC Services Ltd



1 INTRODUCTION York EMC Services Ltd (YES) at the University of York is currently performing a study into the EMC emissions from Switched Mode Power Supplies (SMPSs) and similar Switched Electronic Load Controllers (SELCs) devices. This document is a progress report on the determination of circuit diagrams of SMPSs and similar SELCs. It contains the circuit diagrams of the items which have been purchased to perform this study [1]

1.1 Objectives of the overall study i. Research the market in order to identify a range of products that are based on, or

contain, SMPS or SELC technology, and purchase a number of these products (around 10 in total) such that they represent the range available on the electrical goods market.

ii. Arrange with the Agency’s RTGG laboratory to test the purchased products for both conducted and radiated emissions over a range of agreed likely service conditions for the output load.

iii. Investigate and identify the circuit configurations of the items under test

iv. Produce guidelines or a Code of Practice for the SMPSs and SELCs that would enable the industry to improve the EMC performance of their products when in service.



2 CIRCUIT DIAGRAMS OF THE ITEMS PURCHASED FOR THIS SUDY 2.1 Introduction

This study is based on the investigation into the EMC emissions from off-load Switched Mode Power Supplies (SMPSs) and similar Switched Electronic Load Controllers (SELCs).

A total of 10 items have been purchased for this study: 6 items based on SMPSs and 4 items based on SELCs. The list of the products is enclosed in Table 1.

Item Type of Product SMPS/SELC

1 Mass produced SMPS for a PC SMPS

2 Replacement PC SMPS SMPS

3 DVD player SMPS

4 Sky Digital Box SMPS

5 Printer SMPS

6 Plug-in power supply SMPS

7 One way rotary dimmer SELC

8 Power corded hammer drill SELC

9 Separate speed transformer SELC

10 Courtesy wall light SELC

Table 1: List of items based on the SMPS and SELC Technology

For each of the items, the circuit diagrams have been extracted and component values recorded. The circuit diagrams for each of the items are presented in section 2.2.

2.2 Circuit diagram of the EUTs 2.2.1 Item 1: Circuit diagram for the Mass produced SMPS for a PC

The circuit diagram of the input stage of the mass-produced SMPS for a PC (Item 1) is shown in Figure 1. As can be seen from the figure the SMPS has two input filters: the first filter consists of a bought-in IEC filter and the second filter is integrated on the PCB directly, with common mode choke filtering, differential capacitive (capacitor C1) and differential inductive (inductor L1) filtering. This filtering arrangement could lead to variations in the conducted emission measurements.

The rectification is made through a full-wave bridge rectifier and a switch enables the selection of the input voltage range (110V or 230V).

The SMPS can be divided in two power supplies: the first one consisting of a dual switch power supply using both TRA and TRB (Transformers A and B) and the second consisting of TRC (Transformer C) as a single-switched transformer flyback unit.



2332/sch/09 d

PC SMPS 1 (Power Win) - Input stage

A3

1 1Friday, February 28, 2003

Title

Size Document Number Rev

Date: Sheet of

NOTE:- Transformer windings shown are approximateand relate to a conductivity test only.Position of taps relative to each other hasnot been tested, and may differ to that shown.- Component values or identifiers marked "?"are unknown

3

7

6

5

4

2

TRC

1

6

7

8

5

6

TRA

TRB4

1

2

3

2b

3

4

1b

1a

2aFiltered IEC Inlet

5

RTHNTC?

t1 2

C6470uF

12

C5470uF

12

ZNR1VRSTR?

12

R15330R?

21

C1110nF

12

D??

12

Q32SC3866

1

23

R142R2

21

R17330k

21

Q12SC2625

1

23

D2?

12

R62k7 2

1

R82R2

21

D5? 12

R5100R 2

1

C72.2nF

12

Q22SC2625

1

23

D1?

12

R72k7 2

1

R102R2

21

D4? 12

0.1uF

12

2 x 0.7mH

15

48

E 1

N 2

L 3

3.3nF

12

B1

Plug

12

S?SW SPST

1 2

3.3nF

12

R1820k 2

1

L1INDUCTOR

1 2

R2820k2

1

C2100nF

12

L?Choke

15

48

C1330nF

12

B1

Socket

12

C364.7nF

12

F1

6.3A

1 2

C374.7nF

12

ZNR2VRSTR?

12

C1047uF

12

D7

?

1 2

R18330R

21

ZD1ZENER

12

R161k

21

C12150pF

12

R21100R

21

C91uF

12

C81uF

12

D6KBL406

- +

1

2

3

4

J?Link

S?SW SPST

1 2

R4330k2

1

R3330k2

1

R1339R

21

R1239R

21

C42.2uF

1 2

C33.3nF

12

Figure 1: Input stage of the Mass-produced SMPS for a PC (Item 1)



2.2.1 Item 2: Replacement PC SMPS The circuit diagram of the input stage of the replacement PC SMPS (item 2) is shown in Figure 2.

For this item, the input filtering system is composed of two independent filters: The first filter consists of an IEC filter, which is custom-built. As with Item 1 the second filter is integrated on the PCB and has a common mode choke and differential and common mode capacitive filtering.

A full-wave bridge is used for rectification. The rest of the SMPS similar to Item 1 but with a regulation system based on opto-coupled feedback from the output stage.



2332/sch/08 d

PC SMPS 2 (UPSGuard) - Input stage

A3

1 1Friday, February 28, 2003

Title


Date: Sheet of

NOTE:- Transformer windings shown are approximateand relate to a conductivity test only.Position of taps relative to each other hasnot been tested, and may differ to that shown.- Component values or identifiers marked "?"are unknown

15

18

19

20

21

16

TRC

17

12

11

13

14

5

6

TRA

TRB10

7

8

9

2b

3

4

1b

1a

2aAdditional Input Filter Board

SK2500

Socket

12

F1

6.3A

1 2

TH1NTC?

t1 2

C?

0.22uF

12

L?Choke

15

48

CY2

2.2nF

12

C?470uF

12

BD1RS605

- +

1

2

3

4

CY1

2.2nF

12

S?SW SPST

1 2

C?470uF

12

R3150k 2

1

ZNR1

VRSTR?

1 2

R121k5

21

C3100pF

12

D??

12

R002R2

21

TR12N4401 1

2

3

Q22SC5027-R

1

23

J?Link

D2

?

1 2

R8100k

21

J?Link

C44.7nF

1 2

R21100R

21

C11150pF

12

C522nF

12

D8?

12

C522nF

12

R10100R

21

ISO?PC817

43

R11100R

21

CY3

2.2nF

12

Q42SC2625

1

23

Dx?

12

R72k7 2

1

R51R?

21

D5?

12

D6?

12

R2150k 2

1

C91uF

1 2

R8651R 2

1C104.7nF

12

Q42SC2625

1

23

Dy?

12

R62k7 2

1

R41R?

21

D3?

12

D1?

12

C?

0.47uF

12

LF01Choke

15

48

CONN?

IEC Panel Inlet

E 1

N 2

L3

C02

2.2nF

12

SK2500

Plug

12

S?SW SPST

1 2

C03

2.2nF

12

C710uF

12

C810uF

12

Figure 2:Input stage for the Replacement PC SMPS (Item 2)



2.2.3 Item 3: DVD player SMPS The circuit diagram for the DVD player power supply (item 3) is shown in Figure 3. In this case, both input and output stages are present on the same circuit diagram.

The input filtering for this item is based on differential and common mode inductive and differential capacitive circuits. The rectification is made by four discrete diodes. The system is based around one transformer unit. A single bipolar switching transistor is used, with feedback control once again being provided by a opto-coupled signal from the output. Two output lines are monitored.

On the output side, again half-wave rectifiers are used with reservoir capacitors and various types of filters (capacitive and inductive filtering system).



2332/sch/02 d

DVD Player PSU

A3

1 1Tuesday, January 28, 2003

Title


Date: Sheet of

AC(3)

AC(1)

-27v

+12v

+5v+5v

-12v

S8

S2

S6

S5

S1

P4

P5

P1

P2

P3

S7

S9

S3

S4

NOTE:- Transformer windings shown are approximate and relateto a conductivity test only. Position of taps relativeto each other has not been tested, and may differ tothat shown.- Component values or identifiers marked "?" are unknown

CN1

Socket

12

J4Bead1 2

J1Bead1 2

?AF1

1 2

TH1102?

t1 2

C10.22uF

12 C5

0.1uF

12

LF1Choke

15

48

C647uF

12

C9223(22nF)

12

C1247uF

12

R92k 2

1

C7103(10nF)

12

D5?

12

D7

?

1 2

D13? 12

C1510uF

12

L5?1 2

R267R5

21

C2147uF

12

D12?

1 2

C19470uF

12

L4?1 2

C23100uF

12

C14102(1n)

12

R20100R

21

D15?

12

C2447uF

12

R133k9 2

1

C1510uF

12

U?KA431AZ

3

1

2

hard wired

To Switch

12

J2Link

D21N4005

1 2

D31N4005

1 2

D11N4005

12

D41N4005

12

C8331k(330pF)

12

J6Link

R4560k

21

R5560k

21

TR12N4401

1

2

3

Q1MJE13007

1

23

R2Link

C10223?

12

D10

?

12

R82k7

21

ISO?PC817

43

D6?

12

R6470R

21

R3100k

21

J5Link

C11102(1nF)

12

R24470R

21

R233k3

21

R25470R

21

R2256R

21

J10Link

D13?

12

D17?

12

R27360R 2

1

D19?

12

D11?

1 2

C181000uF

12

L3?1 2

C22470uF

12

C13222k(2.2nF)

12

R1951R

21

D16?

12

R1515k 2

1

R1733k 2

1

R125k1

21

C17

1uF

12

R1151R

21

ISO?PC817

12

R101k 2

1

D14?

1 2

C16102(1n)

12

R21100R

21

J8Link

R182k 2

1

U?78L12VIN

1

GN

D2

VOUT3

R1820k 2

1

Figure 3: Circuit diagram for the DVD player power supply (Item 3)



2.2.4 Item 4: Sky Digital Box SMPS Figure 4 shows the circuit diagram for the Sky Digital box with box input and output.

In this item, the filtering system is based around a common mode choke, differential and common mode inductive filtering and differential capacitive filtering. The rectification is achieved by a full-wave rectifier. An integrated flyback power supply module is used for regulation (TOP224) which is the core of this SMPS. The SMPS is based on one transformer and as in the previous case an opto-coupler is used to provide feedback to regulate the input/output characteristic.

On the output side, half-wave rectifiers are used with reservoir capacitors and various types of filter arrangements (some of which have inductive high frequency filtering, some capacitive filtering and some both).

In this case, two output lines are monitored by the regulation circuit.



2332/sch/01 d

Sky Digibox PSU

A3

1 1Tuesday, March 04, 2003

Title


Date: Sheet of

+8v

+3v3

+5v7

-8v

+20v

+16v

+33v

S1

S2

S3

S4

S5

S6

S7

S8

S9

P1

P5

P4

P2

P3

NOTE:- Transformer windings shown are approximate and relateto a conductivity test only. Position of taps relativeto each other has not been tested, and may differ tothat shown.- Component values or identifiers marked "?" areunknown

SK2500

Socket

12

L2501Toroid1 2

L2500Toroid1 2

T2.5A

FC2501/2

1 2

VDR2500300L20

12

RS2500NTC?

t1 2

C25010.1uF

12 C2504

101k(0.1nF)

12

L2502Choke

15

48

R25014M7 2

1

R25014M7

21

C2506222(2.2nF)

12

C250082uF 420v

12

C??

12

C250247uF 63v

12

R?47R

21

U2500TOP224Y

Control1

Rtn

2Tr

x3

DF08S048A

- +

1

2

3

4

D2500P6KE150

12

R?1k

21

C2507102k(1nF)

12

R?1k

21

D?RK12

12

R?100R

21

C??

12

D?

MD

12R?470R

21

D2501DIODE

1 2

C2513330uF

12

L250447uH1 2

R?100R 2

1

C2517100uF

12

D?SL40C

1 2

C2510680uF

12

L25036.8uH1 2

C2516330uF

12

C2512680uF

12

C??

12C?

?

12

R?4R7

21

R?33k 2

1

R?3k3 2

1

R?6k8 2

1

C??

12

D2502DIODE

1 2

C2514680uF

12

L25056.8uH1 2

R?470R 2

1

C2518330uF

12

D2503?

12

R?1k 2

1

C2519100uF

12

C2515100uF

12

L250647uH1 2

D2504DIODE

1 2

R?10k 2

1

C2520330uF

12

C??

12

R?5k6 2

1

C2511330uF

12

D2505DIODE

1 2

C??

12

D?EG12

1 2

C2509100uF

12

R?18k 2

1

C??

12C2508

68p (?)

12

U?TL431

3

1

2

C?

?

1 2

R?150R

21

R?1k

21

C?

?

1 2ISO?OPTO

ISO?OPTO

Figure 4: Circuit diagram for the Sky Digital Box (Item 4)



2.2.5 Item 5: Printer SMPS The circuit diagram for the Printer (item 5) is shown in Figure 5. Once again, both input and output stages are present on the same circuit diagram.

In this item, the filtering system is based around a common mode choke, and differential capacitive filtering. The rectification is achieved by four discrete diodes. The operation of the power supply is controlled by the DAP07 integrated circuit. A single bipolar switch transistor is used, which has a ferrite bead fitted to its emitter lead. On the output side, in addition to the typical half-wave rectifier circuit, two ferrites beads are fitted to the diode D13, along with a common-mode choke on the output.



2332/sch/10 d

Printer PSU

A3

1 1Tuesday, March 04, 2003

Title


Date: Sheet of


?AF1

1 2

CX10.1uF

12

FL1Choke

15

48

D8

1N4007

1 2

D41N4007

1 2

D31N4007

1 2

D21N4007

12

D11N4007

12

C11102(1nF)

12

L

1

N

1

C82.2nF

12

C11?

12

Q1HNC60F

1

23

R2A51k

21

R5A100k

21

R4A12k

21

J1Link

C52220uF

12

D51N4007

12

R5B15k4

21

R116k2

21

R2B51k

21

L?Bead1 2

D13

?

1 2

TR12N4401

1

2

3

L?Bead1 2

R4B12k

21

R52A1k

21

L?Bead

12

C51?

1 2

R151R

21

ZD1

?

12

R91k

21

R51150R

21U?

DAP07

11

22

33

44 5 56 67 78 8

ZD51?

12

R10R51

21

C12?

1 2R1351R

21

C4?

12

C9?

12

R6887R

21

C21nF

12

R52B1k

21

D61N4007

12

R82k7

21

C5?

12

FL51Choke

15

48 Vo

1

Gnd

1

C110uF

12

Figure 5: Circuit diagram for the Printer (Item 5)



2.2.6 Item 6: Plug-in SMPS Figure 6 shows the complete circuit diagram for the Plug-in Power supply. The filtering system of this item is only based on a common-mode choke. The rectification is based on a full-wave bridge. The system is based on a single switched flyback circuit but using a MOSFET instead of a bipolar transistor.

The output is based on a half-wave rectifier with reservoir capacitor and inductive filter. The output is regulated by the component “U1” which controls the switching MOSFET via an opto-coupler.



2332/sch/05 d

SMPS Plug-in PSU

A3

1 1Monday, February 10, 2003

Title


Date: Sheet of

+

-


CN1

Socket

12

?AF1

1 2

L1Choke

15

48

C11uF

12

C3C

12

C210uF

12

R111k

21

C5C

12

D2?

12

L222uH1 2

D5?

1 2

C8C

12

R3470k

21

R4470k

21

Q1BC817-40

1

2

3

R71k

21

R647R

21

R8100k

21

C22.7nF

12

R262k2 2

1

R24100R 2

1

R130R

21

R272k2

21

D6?

12

R204k7 2

1

D7?

12

C7470uF

12

C?10uF

12

C10C

12

R2147k 2

1

R180R 2

1

R232k2 2

1

R170R

21

R1622k

21

OPTO1LTV4N35

12

R1982k

21

R152R2 2

1

D1BRIDGE

- +

1

2

3

4

R14R7

21

R24k7

21

R547k

21

C4C

12

OPTO1LTV4N35

54

R101R5 2

1

R120R 2

1

D3?

12

R9470R 2

1

Q22SK28651

23

U1ST C938

11

22

33

44 5 56 67 78 8

D?MBAV70

13

2

C9C

12

R2247k 2

1

D4EC9B

1 2

R25

43k

21

U2KA431AZ

3

1

2

R140R

21

Figure 6: Circuit diagram for the Plug-in Power Supply (Item 6)



2.2.7 Item 7: One way rotary dimmer SELC The circuit diagram for the One-way rotary dimmer (Item 7) is shown in Figure 7.

The load switching is carried out by a thyristor. The triggering level is set by two resistors (1.2MΩ and 2MΩ), the diac D1 and the capacitor identified by C? (47nF). In this system, L1 and C1 are used for noise suppression.



NOTE:- Component values or identifiers marked "?" areunknown 2332/SCH/04 d

230Vac 250W Domestic Light Dimmer

A

1 1Tuesday, January 28, 2003

Title


Date: Sheet of

PAD1

1

PAD2

1

S?SW SPST

12

C1100nF

12

R?2M

21

R?1M2

13

2

C?47nF

12

D1

DB3

1 2

L1INDUCTOR

12

Q?SCR?3

12

F?

THERMAL FUSE ?

1 2

Figure 7: Circuit diagram for the One way rotary dimmer (Item 7)



2.2.8 Item 8: Power corded hammer drill SELC Figure 8 shows the circuit diagram for the Power corded hammer drill SELC.

This system is based around an off-the-shelf power control module, which itself has similar characteristics to the previous thyristor based circuit. The only external filtering is made by the capacitor C1.



2332/SCH/07 d

Hammer Drill Motor Control

A

1 1Tuesday, February 18, 2003

Title


Date: Sheet of

To motor /reversal switch

NOTE:- Component values or identifiers marked "?" areunknown- brush wires are wound round toroidal cores atbrush end

On/Off Speed SwitchPAD1

1

PAD2

1

R?2M

21

C?68nF

12 D1

Diac?

1 2Q?SCR?3

12

D?MBAV70

13

2

R?100k

21

R4~2M

21

R3~10M

21

S?SW SPST

12

PAD3

1

PAD4

1

S?SW SPST

1 2

C1330nF

12

Figure 8: Circuit diagram for the Power corded hammer drill (Item 8)



2.2.9 Item 9: Separate speed transformer SELC The circuit diagram for the Separate speed transformer (item 9) is shown in Figure 9.

A full-wave bridge rectifier is connected to a standard linear transformer (not shown) at the input. The trigger controller is similar to the previous thyristor circuits. The components D5 and R5 are functional indicators only. On the output side, differential capacitive filtering is performed by the capacitors C4, C3 and R6.



2332/SCH/03 d

Mini-Drill Speed Controller PSU

A

1 1Tuesday, February 18, 2003

Title


Date: Sheet of

NOTE:- Component values or identifiers marked "?" areunknown

AC in

from transformer

12

C210nF?

1 2

C1220uF

12

2 Pin Connector

To Drill

12

D1?

1 2

D2?

1 2

D3?

12

D4?

12

R1820k 2

1

R368k 2

1

R2100k

13

2R41k5

21

Q1SCR CAG3

12

D5LED

12

R51k 2

1

R6100R 2

1

C3100pF

12

C410nF

12

Figure 9: Circuit diagram for the Separate speed transformer (Item 9)



2.2.10 Item 10: Courtesy wall light SELC Figure 10 shows the circuit diagram for the Courtesy wall light SELC. The sensor circuitry is on a separate board and is not shown.

For item 10, a differential capacitive filter is used at the input.

The triac (BTB08) is used to switch power to the lamp, with L1 acting as suppression. The remainder of the circuitry controls the triggering of the triac. There appears to be no further mains filtering,



2332/SCH/06 d

PIR Courtesy Light - Lamp Switcher

A

1 1Thursday, March 06, 2003

Title


Date: Sheet of

To LampLive

NOTE:- Component values or identifiers marked "?" areunknown

C810uF

12

R3330k 2

1

Q32SC945 1

2

3

C10.22uF

12

C30.47uF

12

C5470nF

1 2

C6470nF

12

J1

1

D3?

1 2

D2?

1 2

J5Link

C4470uF

12

J2

1

D41n4148

1 2

D11n4002

1 2

Q22SC945

12

3

JP1

HEADER 6

123456

R162R

21

R21M 2

1

D13?

12

R4100k 21

L1Coil1 2

R81M 2

1

R53k3 2

1

J3

1

Q?BTB08 600S

3

12

R72k7 2

1

R9330k 2

1

Figure 10: Circuit diagram for the Courtesy wall light (Item 10)



3 CONCLUSIONS The presentation of the circuit diagrams has shown that there are some differences between the different types of SMPSs and SELCs. These are mainly related to the filtering of the noise and the arrangement of the filtering components, the number of transformers, and types of regulator topologies used (e.g. opto-coupler…).

It is expected that these differences will affect the EMC performance of each of the items. Performing a detailed analysis of the testing results, and modelling of the items should enable correlation of the emissions with the circuit topologies.



4 References [1] York EMC Services Ltd report – Document number 8202CR1 – “Investigation into the EMC emissions from off-load Switched Mode Power Supplies (SMPSs) and similar Switched Electronic Load Controllers (SELCs) – Deliverable 1 – Interim report.

Documents

Tender for performing An investigation into the EMC ... EMC Services Ltd (YES) at the University of York is currently performing a study into the EMC emissions from Switched Mode Power