AGENDA - EMC PROBLEM DIAGNOSTICS AND MITIGATION

If there was ever a concrete example of Murphy's Law then EMI/EMC troubleshooting has to be it. No matter what fix is applied the problem never seems to go away. It's like playing with a water balloon. Squeeze it down in one location and it bulges out in another. The principle reason for that is the problem results from weird circuit resonances and adding or subtracting inductance and/or capacitance to fix the probleem at one frequency shifts it to another. Stop! Don't remove that fix . . . add another and another and so on until the problem has been beaten into submission. Then begin to remove the fixes one at a time until no more can be removed without returning the problem. Of course even though the brute force plan just described works, it's not very efficient. It's like trying to find a black cat in a dark room.

Solving the emission and susceptibility problems should use a sound scientific method. Its all a matter of electromagenetic coupling and there are 4 primary coupling processes: Conductive, Capacitive (EF), Inductive (HF), and Radiative (PW). Start by investigating the problem using FAST analysis: Frequency, Amplitude, Space, and Time and locate the problem area within the system. Then go for it. Of course taking this course will speed things because scientific troubleshooting is what the course is all about.

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COURSE OVERVIEW AND EXPECTATIONS

EMI/RFI/EMC BASICS
Terms and Definitions
Time to Frequency Conversion
Acronyms Used in Military EMC
Examples of Interference Conditions
Interference Sources
Interference Receptors
Overview of Typical EMI Levels/Coupling
Power Line Disturbances
Transients - ESD, Lightning, EMP
F.A.S.T. Analysis
Systems Emission/Immunity
Comparison of MIL-STD-461E and FCC/EU Commercial EMC Requirements
MIL-STD-464A/C Requirements for Commercial and NDI Equipments

DIAGNOSTIC INSTRUMENTS AND PROBLEM SOLUTIONS
EMI Deductive Troubleshooting
System EMC Fixes
EMI Fix-It Tool Kit
Typical Current Probe Factor
Design & Development Emissions Testing
Minimum EMC Trouble-Shooting Equipment
Spectrum Analyzers and EMI Receivers
Wide-band Scopes and Probes
Antennas and Field Probes
RF Current and Voltage Probes
Power-Density and milliGauss Meters
Power Disturbance Analyzers
Time-Domain Reflectometers
Handy Talkies (HT) and ESD Generators

PRINCIPAL EMI-SUPPRESSION COMPONENTS AND METHOD
Power, Control, and Signal Line Filters
Transient/Surge Suppressors
Parasitic Inductance and Capacitance Controls
Minimizing Ground-Loops
Common-Impedance Fixes
Common Mode, Field-to-Cable Reduction
Differential Mode, Field-to-Cable Reduction
Crosstalk Controls
EMI Shielding and Shielded Enclosures
Minimizing Aperture Leakage
Victim Hardening
Solution Matrix
Installation Guidelines and Procedures

DIAGNOSTIC TECHNIQUES AND PROCEDURES
The FCC/EU Regulation Limitations
Tests That Do Not Require Instruments
Diagnostic Techniques and Methods
Forced-EMI Failure Methods
Procedure Diagrams

DETERMINING/TROUBLE SHOOTING SYSTEMS EMC PROBLEMS
Systems Problems
Systems Test Approach
Data Collection
Writing ElectroMagnetic Scenarios
Solving Problems
Data Collection
Changing Electromagnetic Ambient (Function of Mission Profile)
F A S T (Isolation by Frequency, Amplitude, Separation, Time)

EMI COUPLING
Conductive
Inductive (Near Field)
Capacitive (Near Field)
Radiative (Far Field)

DIAGNOSTIC PROCEDURES AND CASE HISTORIES
Inside the Equipment or Product
Within the Room or Area
Within the Building
Distant Locations
Hospital EMI Problem
Oil-Drilling Site, Cable Problem
Faulty Category-5 Cable Performance
Industrial-Process Control Failures
Broadcast Transmitter Jams Computer Network
Large-Crane Control Problem
Cab Radio Jams Audio Studio
Aluminum Window which Shocks

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