Tuesday, 2 February 2016

Type OF EMC Standards

Directive 
In order to ensure that the equipment are designed to perform as close as possible in its environment, the European standards making body CENELEC(European Committee for Electrotechnical Standardization) has been mandated to produce standards for use with the European EMC Directive. For telecommunications equipment ETSI(European Telecommunications Standards Institute)is the mandated standards body.

There are 3 types of standards : 
a) Product or product family standards, relating to a specific product or product family group. The product standards take precedence over the generic standards and are drafted to cover the particular range of product types.
These standards should refer to the Basic Standards for test methods wherever possible. It wil consist of defining what tests to carry out, what levels or limits, and what operating conditions and performance criteria to apply. These are prepared by IEC, CENELEC or CISPR.
b) Generic Standards relating to a particular environment of use. At present these are for: 
(i) Domestic, Commercial and Light Industry
(ii) Industrial environment
c) Basic Standards, to provide general information and relate to the disturbing phenomena and testing and measuring techniques. Basic standards do not contain limits or performance criteria. They serve as a reference for product standards and will not normally be listed in the Official Journal, but will be referred to in product or generic standards.


List of Product Standards related to household electrical appliances 
i) EN 55014 Limits and methods of measurements of radio disturbance charateristics of household electrical appliances, portable tools, and similar electrical apparatus (CISPR 14).
ii) EN 55015 Limits and methods of measurement of radio disturbance characteristics of electrical lighting and similar equipment (CISPR 15).
iii) EN 55104 Electromagnetic compatibility - immunity requirements for household appliances, tools and similar apparatus (CSIPR 14-2)


Generic Standards - Emissions 
i) EN 50081 Part 1 Generic emission standard, part 1: Residential, commercial and light industry environment.
ii) EN 50081 Part 2 Generic emission standard, part 2: Industrial environment.


Generic Standards - Immunity 
i) EN 50082 Part 1 Generic immunity standard, part 1: Residential, commercial and light industry environment.
ii) EN 50082 Part 2 Generic immunity standard, part 2: Industrial environment.


Basic Standards
i) EN 61000-3-2 Electromagnetic compatibility (EMC). Limits. Limits for harmonic current emissions (equipment input current up to and including 16 A per phase)
ii) EN 61000-3-3 Electromagnetic compatibility (EMC). Limits. Limitation of voltage changes, voltage fluctuations and flicker in public low-voltage supply systems, for equipment with rated current 16 A per phase and not subject to conditional connection.
iii) EN 61000-4-1 Electromagnetic compatibility (EMC). Testing and measurement techniques. Overview of IEC 61000-4 series.
iv) EN 61000-4-2 Electromagnetic compatibility (EMC). Testing and measurement techniques. Electrostatic discharge immunity test. Basic EMC publication.
v) EN 61000-4-3 Electromagnetic compatibility (EMC). Testing and measurement techniques. Radiated, radio-frequency, electromagnetic field immunity test.
vi) EN 61000-4-4 Electromagnetic compatibility (EMC). Testing and measurement techniques. Electrical fast transient/burst immunity test. Basic EMC publication.
vii) EN 61000-4-5 Electromagnetic compatibility (EMC). Testing and measurement techniques. Surge immunity test.
viii) EN 61000-4-6 Electromagnetic compatibility (EMC). Testing and measurement techniques. Immunity to conducted disturbances, induced by radio-frequency fields.
ix) EN 61000-4-7 Electromagnetic compatibility (EMC). General guide on harmonics and interharmonics measurements and instrumentation, for power supply systems and equipment connected thereto.
x) EN 61000-4-8 Electromagnetic compatibility. Testing and measurement techniques. Power frequency magnetic field immunity test. Basic EMC publication.
xi) EN 61000-4-9 Electromagnetic compatibility (EMC). Testing and measurement techniques. Pulse magnetic field immunity test. Basic EMC publication.
xii) EN 61000-4-10 Electromagnetic compatibility (EMC). Testing and measurement techniques. Damped oscillatory magnetic field immunity test. Basic EMC publication.
xiii) EN 61000-4-11 Electromagnetic compatibility (EMC). Testing and measurement techniques. Voltage dips, short interruptions and voltage variations immunity tests.
xiv) EN 61000-4-12 Electromagnetic compatibility (EMC). Testing and measurement techniques. Oscillatory waves immunity test. Basic EMC publication.

These listings are not exhaustive but cover the basics tests needed for household appliances. When performing compliance testing, one should verify which standards are mandatory for a product along with the required test levels and performance criteria. 

Friday, 17 April 2015

TYPICAL CONVERSION FORMULAS



TYPICAL CONVERSION FORMULAS

What is Feed Through Capacitor ?



Feed through capacitors are originally designed for DC power line in RF module or system. It passed through the DC (and low frequency signals) but blocks the RF energy. In practical use the: feed through capacitors are fitted to the metal case of the RF module on holes where the wires enter the system. They let the signal pass through but will stop the RF from escaping from the device through that hole to the outside wiring.
A feed-through capacitor in which a composite dielectric layer made of a mixed material containing a resin material and dielectric material powder is arranged between a feedthrough terminal and an outer electrode terminal surrounding this feedthrough terminal, a capacitance being formed between the feed through terminal and the outer electrode terminal.
A ceramic plate is formed with sleeve-like protuberances with an internal aperture, the plate is metalized around the sleeve-like protuberances, and feed-through conductors are placed through the apertures, the metallized coating around the protuberances and the feedthrough conductor forming the capacitance; the metalized coating is removed from the zones surrounding the terminal ends of the openings, to provide ceramic insulation material between the feed-through conductors and the metalized coating. The metalized coating may be removed by grinding.
Feedthrough capacitors provide a low impedance path to ground for high frequency signals. This allows any undesirable high frequency noise to bypass the functional circuit.

Tuesday, 24 March 2015

Q.4.What is Ground Plane ?

Q.4.What is Ground Plane ? 
Ans.Ground Plane is the simulation of actual installation plane used for the EUT.

1) If the actual installation is unknown or multiple installations are expected, then a metallic ground      plane shall be used.
2) The ground plane plays an important role in obtaining the most realistic test results.
3) It is also necessary to meet the electrical safety.
4) Generally metallic ground plane is used if the EUT has multi-plane installation.

Q.2.What is Electromagnetic Interference (EMI) ?

Q.2.What is Electromagnetic Interference (EMI) ?
 Ans. Electromagnetic interference is the frequency spectrum pollution
which degrades the performance of electrical/electronics equipment and system.

Q.1. What is Electromagnetic Compatibility(EMC) ?

Q.1. What is Electromagnetic Compatibility(EMC) ?
Ans. Electromagnetic compatibility is the ability of the equipment or system to function as designed in its intended operational environment without adversely affecting the operation of other or itself being affected by them. 

Monday, 23 March 2015

Q.3. What is LISN ?

Q.3. What is LISN ?
Line Impedance Stabilization Network (LISN) is a device specified by different standard to be used as impedance matching system at supply power line port of the equipment to carry out various EMC/EMI testing measurement accurately and precisely as per the EMC standard.
1.)    TRADITIONAL MIL STD LISN BLOCK DIAGRAM:
        2.)    TIPICAL COMERCIAL STANDARD LISN