Military Aerospace
A major manufacturer of military and civil aircraft systems engaged our services to investigate failures of a battery charger for the Lockheed Martin Joint Strike Fighter to meet conducted emissions to FCC Part 15 and CISPR 22 for European CE Marking. There were also issues with variation in the measured results between the customers facility and an external test facility. We carried out experiments and performed a theoretical assessment of the chargers input mains filter. Working with the project engineers, we were able to arrive at a suitable solution to meet the requirements of FCC and CISPR 22 and identified weaknesses in the design of the line filter. We were also able to resolve the differences and obtained near identical results between the two facilities.
Military Aerospace
A major manufacturer of military and civil aircraft systems engaged our services to investigate susceptibility issues with a revised version of the cockpit display for the European Fighter Aircraft (EFA Typhoon Tranche 2). We devised a suitable setup and identified the problems and source of ingress of the rf conducted disturbances. Modifications to the support equipment and sanitisation of the test set-up resulted in a sufficient improvement to meet the requirements in the time available.
We were also requested to perform a theoretical assessment of an auxiliary display for the same aircraft where susceptibility and failures were experienced during LEMP-1, LEMP-2 and NEMP testing. We identified a number of weaknesses in the design of the units power supply. Modifications to the test method and set-up resulted in an acceptable performance for the customer although the unit was still intrinsically susceptible.
Civil Aviation
A major manufacturer of military and civil aircraft systems engaged our services to handle all the EMC aspects of two new pieces of equipment that formed part of the fuel system for a new variant of a large commercial aircraft manufactured by a major American manufacturer. The products were an extension to an existing system and involved one brand new product and one redesigned product. We defined the test procedures, prepared the qualification test plans, designed and manufactured the support equipment and cable harneses and organised and supported the testing at a leading UK test facility. We were also responsible for producing full reports on the tests and advised on modifications where minor problems ocurred. Prior to the qualification tests, we carried out investigative and de-risking work using the in-house facilities and a local extrnal test facility.
Telecommmunications
A large international telecommunications
company engaged our services to perform a range of services spanning
2 years which included CE certification of the system components
for a newly developed W-CDMA
point to multi-point telephony system. Initial tests showed serious
failure to meet the EMC requirements and we worked with the designers
to achieve initial fixes followed by a redesigned system with
significantly improved EMC features which achieved full compliance
at the first attempt. We produced an EMC Control Plan which defined
the procedure for controlling EMC within the project and reports
covering each of the tests.
We were then asked to work with the Company's EMC and Compliance
Engineer to design and commission an in-house pre-compliance EMC
facility with a budget of £500,000. This included a 7x3x3m
ferrite and absorber lined fully anechoic chamber, calibrated
to 18GHz, with a 6.5x3x3m screened room attached. The facility
also had a separate copper ground plane, was fully fitted with
power and data services and had a full range of emissions and
immunity test equipment.
Telecommmunications
The same telecommunications company retained
our services for a further 4 years to work on the development
of a new range of W-CDMA UMTS
base stations and the design of a 'common platform' upon which
all new base stations (UMTS, CDMA2000 etc.) would be based. We
worked closely with the company and formed a team of EMC Subject
Matter Experts with representatives in Germany and the USA. The
team developed an EMC policy to be used on the common platform
and devised a series of budgetary performances for each of the
major sub-systems which would ensure that, whatever combination
was used in any given system, compliance with EMC would be achieved
to a high degree of confidence. The requirements were published
in the hardware design document for the common platform and the
data was presented in a form which could be easily transferred
to sub-system specifications and purchase requirements for products
supplied by third party vendors.
We produced an EMC Control Plan for the Client which stated the
process that would be used to ensure that good EMC design practice
and screening was being carried out. The plan detailed the strategy
from the initial publication of the system level requirements,
through early development to pre-production, compliance with the
regulatory requirements and installation and maintenance of production
equipment. Cross links were made to the hardware design review
processes.
The EMC facility we had previously commissioned was used during
development to test samples of the sub-assemblies against the
budgetary requirements and products which did not meet the requirements
were rejected for modification by the external vendors or by the
internal design teams. The result of this was that five different
systems achieved CE Certification first time and significant costs
were saved by not having to perform remedial work and re-test.
In the USA, savings of hundreds of thousands of dollars were made
because multi vendor units would have required formal testing
to be approved for use by the FCC.
As each vendor manufactured to the same stringent specification,
only one set of tests was deemed necessary, the remaining units
requiring only a waiver letter.
For the same client, the pre-compliance facility was relocated
as part of company restructuring. The anechoic chamber and screened
room were replaced by one larger semi-anechoic chamber and a larger
turntable was introduced. New Emissions and Immunity software
was added and the range of antennas increased to enable measurement
to 26GHz.
Industrial
A manufacturer of buried cable locators, tracing equipment for plastic mains pipes and inspection cameras for underground ducts (e.g. mains sewers) used our services to vet their products for EMC as part of their self certification programme. We were able to highlight flaws in a printed wiring board which rendered one of the products susceptible to external disturbances and so effect an improvement such that compliance could be declared. We were also able to recommend a filter change to tracing equipment for long distance pipe work which overcame an EMC problem and also reduced the manufacturing cost of the product.
Telecommunications
A large data networking company engaged our services to vet their existing ISDN terminal adapters, Bridgers and Routers for EMC and to advise the design engineers on good EMC design practice. We were able to demonstrate that some products were compliant but could be non-compliant when fitted with some of the optional expannsion modules. We were also instrumental in the redesign of some of the smaller products which had fundamental EMC design flaws.
Railway Transportation
A major telecommunications company, with a contract with London Underground Limited (LUL) to supply communications systems for the Jubilee Line Extension, engaged our services to vet equipment supplied by sub-contractors for EMC to ensure that all component parts of the system met the requirements stipulated by LUL. We were able to demonstrate that all the equipment to be supplied by sub-contractors was fully compliant with LUL requirements as a result of existing certification to the EMC Directive.
Telecommunications
An international communications company engaged our services to commission their in-house EMC chamber with automatic measuring instrumentation and software. The component parts had been purchased but never integrated into a functional test facility. We were able to make the facility operational and then use it to test the company's range of datacomms products and, in conjunction with external test houses, assess which products could be CE marked when the EMC Directive came into force.
Civil Aviation
To provide EMC expertise to the designers
of an in-flight passenger entertainment system to be installed
in a new aircraft for service with both an American and a British
carrier. We were responsible for vetting the designs of the major
components of the system for EMC and working with the unit designers
to ensure that good EMC design practice was incorporated into
the design.
Page last updated: 12 May 2008 17:00:27