ELECTROMAGNETIC COMPATIBILITY

Electromagnetic Compatibility

Table of Contents

1INTRODUCTION4

2PRODUCT DESCRIPTION4

3THE EMC DIRECTIVE7

4SUBSYSTEMS OPERATION PRINCIPLES (IDENTIFICATION OF INTERFERENCE SOURCES)8

4.1Switch Mode Power Supply Unit:8

4.2Temperature sensor (LM35)8

4.3Signal conditioning unit9

4.4Micro-processor board with ADC unit10

4.5Display unit10

4.6RS232 protocol11

4.6.1 TEST EQUIPMENT11

4.6.2 TEST POINT DIAGRAM11

4.6.3 TEST DATA12

4.6.4 TEST SETUP12

4.6.5 TEST RESULTS13

4.6.6 TEST DATA13

5EMC DESIGN RULES14

5.11.1    Identification of interference sources14

5.2The route to ground14

5.3System partitioning15

5.4RF Immunity and ESD16

5.4.1 EN 61000-4-5 SURGE IMMUNITY TEST DESCRIPTION16

5.4.2 TEST SETUP16

5.4.3 TEST RESULTS17

5.4.4 TEST DATA17

5.4.5 TEST EQUIPMENT18

5.5Power provide routing18

5.6PCB Layout and Grounding18

5.7Shielding19

5.8Filtering19

6EMC CONCEIVE DIRECTIONS APPLICATIONS20

6.1Subsystem I (SMPS)20

6.2Subsystem II (LM35)20

6.3Subsystem III (signal status unit)21

6.4Subsystem IV (microprocessor with ADC)21

6.5Subsystem IIV (display unit)22

6.6RS232 protocol22

7DESIGN DEVELOPMENT22

8MITIGATION23

9RECOMMENDATIONS FOR SCHEME HARDENING25

10CONCLUSION26

11REFERENCES28

Introduction

The objective of this work is to study the diverse matters engaged in the conceive of conceive for compliance with EMC. It is significant for electric / electrical devices manufacturers, to confirm their goods rendezvous befitting measures of EMC in alignment to endow them to deal their goods at a nationwide or worldwide level.

This report will address the next questions:Definition of the distinct conceive directions EMC.

Implementation of the diverse conceive directions EMC.

Implementation of the directions will be advised as a boiler command merchandise at diverse phases extending from constituents and published circuit board grade to grade control.

The cause for EMC progressively significant topic in the electric / electrical devices constructing commerce due to expanded complexity in electronics, offered in distinct goods on the household and developed scale.



Product Description

In this part an overview of the merchandise is offered to endow comprehending of the distinct reasons each subsystem does. Following is the merchandise overview as suggested in the inquiries sheet.This merchandise comprises of five distinct sub-systems (SS), A-B-C-D-E.

1.  SS A is a power provide feeding the other four sub-systems, this is a swapped mode kind (running at 40kHz), that makes 5Volts at 0.5 Amperes and 12 Volts at 5 Amperes from a 240Vac 50 Hz supply.

2.  SS B, C, D and E are attached competently in series.

3.  SS B is a factual centigrade warmth sensor (LM35); it is attached by a two-metre lead to SS C.  The LM35 desires between +9 and 20 volts to power it; its answer is 10mV/ ?C over the variety -55? C to +150 ?C.

4.  SS C is a pointer conditioning circuit taking the voltage from SS B and altering it to between 1 volt and 5 volts. 

5.  SS D is a microprocessor board with an on-board ADC and an oscillator running at 100 MHz.

6.  SS E is a brandish and interfacing board, with yields to a five-digit LCD, an alert circuit and handicapping scheme for a boiler; and the last yield is attached to an RS232 socket, (to be utilised to attach to the command room 20 metres distant from the boiler).  A keypad is climbed on on to this board to program, set the warmth and aid in calibrating the system.

The general obligation capacity of less than 30 watts for the scheme and thus the need for cooling (Steiner 2004). To the south of schemes (with the exception of ...