Aerco now offers a complete supply and kitting service to installers of obstruction light systems that are required by FAA and ICAO regulations on structures that exceed 45 metres in height and are mandatory at airfields, refineries, offshore oil and gas rigs, chemical plants and construction sites.
Using a combination of LED beacons and other products from world leading manufacturers the experienced, in-house design team at Aerco ensures the correct components are selected for each installation and that they are delivered on time.

Products include LED obstruction light assemblies and beacons, photocells, controllers and indicators in addition to all the ancillary equipment required for a successful, cost-effective solution such as junction boxes, cables, connectors, conduit and fixings. All packages can be customised to suit individual installations.

Traditional installations have used incandescent lamps but now LED beacons are preferred because of the lower power consumption and longer life of LED light sources that greatly reduce maintenance, servicing and operating costs.

The Aerco kitting service is designed to cater for new installations and for upgrading of existing systems with LED-based products.

Contact Mike Strevens for further details

The fact that discrete electronic components are becoming more efficient and therefore generate less heat is of no consolation to the engineer responsible for heat management of electronic enclosures. Under competitive pressure, designers continue on a relentless quest to cram more capability into smaller areas thus creating more heat and less space – the worst possible scenario for the heat management engineer.
In addition, modern electronic systems are becoming ever more complex and the cost of failure due to overheating is prohibitively expensive. There are numerous methods of removing unwanted heat such as Peltier thermoelectric coolers, heat pipes and water cooling modules. However, in the vast majority of cases the ubiquitous equipment fan, in one of its many guises, remains the chosen method.
The same but different
Ranging from small instrument cases, through desk-top enclosures and studio desks up to large, free-standing cabinets, enclosures come in all shapes and sizes, each one with its own unique characteristics in terms of cooling requirement and shape. Operating environments are equally diverse varying from the benign, air-conditioned, temperature controlled, clean rooms to harsh and hostile high temperature environments such as manufacturing plants.
The right place
Cooling fans need to be located within the enclosure and in the best possible position to provide maximum cooling effect. There is nothing more frustrating from a thermal management point of view than to see an enclosure that has the cooling device bolted on to the outside of the enclosure. This is a sure sign that cooling was an afterthought, a process that is unlikely to achieve the most effective solution.
The fan must be located in the best position to ensure the optimum air path and it may be that more than one fan is required to deal with overall cooling and specific hot-spots. Whatever the final layout, it is highly recommended to draw ambient air into the enclosure and exhaust warm air. This means that lower temperature air passes over the bearing of the fan thus optimising its life.
Don’t yield to the pressure
To choose the right fan for the job requires accurate calculation and interpretation from data provided by the fan manufacturer and it is a relatively simple job to calculate the air volume required from the formula: Airflow (l/s)/1.2 x ∆t (ºC) = P(W).
However, airflow is always quoted in free air and it must be remembered that the system pressure, the pressure drop across the enclosure caused by the various components and restrictions to airflow, has a vital bearing on fan performance.
It is possible to measure pressure drop by using a venturi tube and anemometer but this is a fairly complicated task and may require the assistance of the fan manufacturer or a specialist laboratory. In the real world the task can be accomplished by intelligent and experienced interpretation of the fan performance curve from which the airflow that the fan will achieve at any given pressure will establish what is known as the ‘duty-point’ of the fan.
The right type
Choosing the right fan for the job really is horses for courses and will depend on the outcome of the deliberations described earlier. Although AC fans still have their place for some applications the superior efficiency, flexibility and controllability of DC fans mean they will be chosen in the vast majority of cases.
In general terms, axial fans give high volume but do not work well against high system pressure; blowers provide less volume but work well at higher pressures while air wheels deliver both high volumes and high pressures. At Aerco we supply axial, flat axial, centrifugal blowers, single and double inlet, skeleton fans, cylindrical air wheels and backward curved impellers. The list is too long to discuss at length here but an experienced cooling specialist will establish the best choice very quickly by analysing the space available, the air volume required and the anticipated system pressure.
The intelligent approach
Most modern, DC fans provide signal wires that allow monitoring and control of fan speed meaning that the system temperature can be controlled within strict parameters. These signals can be used to control, with a high degree of accuracy, the cooling rates within the enclosure, the noise levels of the fans and also provide audible or visual signals to identify potentially damaging reduction of fan speed or, in extreme cases, fan failure.
The right accessory makes all the difference
We have said that every component in the housing will increase system pressure but it is worth noting that the use of a purpose-built wire finger guard creates less restriction than a pattern of punched holes in the housing. The sharp edges of a punched hole create harmonics in the airflow causing turbulence and greater resistance thus affecting both the inlet and exhaust flow of the fan.
While on the subject of accessories, due care must be taken to consider access to the enclosure for maintenance and fan replacement and also the judicious use of filter assemblies will ensure they are in keeping with the style of the cabinet.
Think the whole package
Other aspects to be considered are the environmental conditions and the required IP rating of the fans and it is very important that the projected life of the fan matches that of the system to be cooled. In general terms, sleeve bearings are less expensive and quieter than ball bearings; ball bearings provide maximum life while newly developed hybrid bearings provide an affective compromise.
It is a simple fact of life that the earlier cooling is considered in the design cycle the more effective and efficient the overall system will function and the less likely that those costly down-times will occur.

The nature of warfare is changing, resulting in new requirements for vehicles. Whilst there is a persistent need to protect troops from mines, roadside bombs and IED’s using highly armoured patrol vehicles, the consequent escalation in armour and protection has led to vehicles designed to move troops across country and rough terrain becoming increasingly heavy and cumbersome to the point where they may be described as “mobile pillboxes”. For example the M1151 Humvee weighs more than twice the original model, the M998, and all the additional armour and equipment, whilst having its place, means the vehicle can no longer fulfill many of the roles for which it was originally designed.

These developments, coupled with a continuing and increasing need to move small bodies of men over short range and across extremely rough terrain, have highlighted the need for much smaller, lighter, relatively unarmoured vehicles to fulfill a range of missions. Thus, the light strike vehicle (LSV) was born for fast hit-and-run raids, reconnaissance missions, border and security patrols, special operations support and counter-insurgency work. Whereas traditional vehicles are having to be fitted with six inch thick blast protection panels, it is much harder to set an IED trap for an LSV that does not have to use roads or predictable routes. This allows the LSV to remain light, fast, agile and true to its original design intentions whilst also maintaining a reasonable payload capacity.

The Solution

The PHOBOS system has been developed to provide an operational and commercial solution for forces and organisations requiring a LSV capability.

Based around a core design that ensures high levels of parts commonality and minimizes the time from order to delivery, PHOBOS can be configured to satisfy a range of operational requirements. These include:

·        2 man extreme terrain reconnaissance vehicle

·        3 man light strike and reconnaissance vehicle

·        4 man light strike and reconnaissance vehicle

·        2 man PHOBOS utility / pickup for remote forward operating positions

·        Casualty extraction / transport vehicle

Development to date

A prototype vehicle was built and has been in testing for over 12 months during which period refinements to the original concept have been identified. Testing included assessing several different types of suspension units to find the ideal solution offering performance, strength, ease of maintenance and “tuneability” to allow one type to meet the range of needs across the PHOBOS system.

The spaceframe has been re-designed to incorporate these improvements while increasing strength and occupant safety. The re-design has also been focused upon producing a frame design that can be built cost effectively. To this end, the frame is designed to be built as a set of two-dimensional sub-assemblies that can be assembled in simple planar jigs before construction of the final assembly that is largely self-jigging.

A pre-production vehicle (two seater) is now in assembly. This is being used as the base to develop modular wiring and plumbing systems and other details prior to final design for series production.

The PHOBOS concept and model has been discussed with a number of senior military and security personnel, and received favourable responses. It has already attracted interest from a western European customer looking to source a three-seat platform for a North Asian client.

Specification is as follows

TIG welded spaceframe built from Clubman 500 CDS

110″ wheelbase

Double trianguated four link suspension front and rear

16″ travel suspension struts all round, springless, internal hydraulic bump and limit stops, fully adjustable

Full hydraulic high speed steering

Ford PUMA 2.4 l diesel engine (as in current Land Rover Defender)

4 speed ZF automatic box, fully adjustable shift pattern

Land Rover full-time 4×4 transfer case with locking differential

Custom axle housings

High Pinion 9″ differentials with air operated lockers

1.5″ 300M 35 spline shafts all round

Axle is built to be disassembled / repaired very quickly. For example outer knuckles are held on by 2 bolts, unit bearings are pre-assembled and replace with only 4 bolts.

37″ x 12.5″ tyres (can run up to a 42″)

Forged aluminium rims with internal beadlocks

HIgh performance winches front and centre / rear

FIA approved / burst proof / anti-explosion fuel cells giving over 1000km range

Panels are kevlar composite with a carbon fibre outer layer

To see the original extreme motorsport version in action click here

For more information contact Mike Strevens at Aerco. mstrevens@aerco.co.uk

Our resident geek Mike Strevens took a couple of days out to visit the Oxley Manufacturing Sites last week in Cumbria.

He was in nerd heaven when Oxley’s Mark Johnson walked him around the entire manufacturing process for the discreet/EMI filters.

Oxley are leading specialists in the effective suppression of electromagnetic interference with a wide range of EMI/RFI filtering solutions. To help you solve your EMC problems, through Aerco, Oxley can advise on the most suitable filter solution for your specific application from the standard product range or develop a custom filter solution if required. 

Each filter is hand made to suit the indivdual requirement of the customer and will suit virtually any connector on the market.

Chassis Mounting Filters

A wide range of chassis mounting filters are available. The extensive range includes solder mounted, threaded and press fit. Many have hermetic versions and all are designed and manufactured to the highest quality.

PCB Mounting Filters

Designed in both through hole and surface mounting configurations, the Oxley range of PCB mounting filters offers both C and PI section filtering. Surface mounting devices can be supplied taped and reeled where required.

Filtered Connectors

Utilising design, engineering and manufacturing experience Oxley can offer filter solutions for circular, rectangular (D-Sub and miniature D-Sub), ARINC, and DIN configurations. Extensive in-house ceramic production facility can supply high quality planar, tubular and discoidal capacitors to provide a total filtering solution.

Filter Arrays

Oxley specialise in providing a unique service for the design and integration of filter capacitors into equipment for a specific customer application. Utilising in-house design, assembly and manufacturing facilities we provide high quality components to both military and industrial applications.

Ceramic Planar Capacitor Arrays

Oxley are at the forefront of the development of planar capacitor arrays. Utilising high quality ceramic tape technology, we are able to supply planar arrays for both standard connector plan forms and special requirements.

FOR MORE INFO CLICK HERE

Introducing the Honeywell SS30AT Bipolar Hall-Effect Magnetic Position Sensor, available from Aerco in a subminiature SOT-23 surface mount package that takes up less space on the printed circuit board (PCB). Available on tape and reel, the SS30AT often allows for lower-cost pick and place assembly, helping to reduce manufacturing costs.

The SS30AT is a very small, versatile, digital Hall-effect device operated by the magnetic field from a permanent magnet or an electromagnet designed to respond to alternating North and South poles.

The SS30AT sensor is:

Price competitive: Honeywell has optimized the size of the integrated circuit, saving on manufacturing costs while still meeting customer requirements. These cost savings result in lower costs to customers.

Economical: Package is supplied on tape and reel, often allowing for automated, lower-cost pick and place assembly which helps the customer to reduce manufacturing costs.

Small: Small footprint takes up less space on the PCB, typically allowing for more components on the same board.

Flexible: Synching output with open collector allows the sensor to interface with many electrical components without buffering; 4.5 Vdc to 24 Vdc supply voltages and operating temperature to 125 °C [257 °F] enhance application flexibility.

Stable: Thermally balanced integrated circuit provides stable operation over a full temperature range.

Safe: Built-in reverse voltage protection provides enhanced circuit protection.

Potential transportation and industrial applications include speed and RPM sensing, tachometer, motor and fan control, electric vehicle control, convertible roof position, flow-rate sensing, brushless dc motor commutation, and robotics control.

Contact Aerco’s free DESIGNSUPPORT service for further details

Aerco are now stocking a range of Honeywell Resolvers and Pancakes, (not with) Lemon Juice and Sugar.
Resolvers are absolute rotary and angle sensing electromagnetic transducers or transmitters (RX) that convert mechanical postition into an electrical signal.

Types of Resolvers

Pancake Resolvers: Supplied as separate stator and rotor assemblies which mount to customer system. Available in single or dual speed configurations they come with a flange for mounting or sleeves and hub which bond to customer system.

Brushless Pancake Resolvers: What defines a ‘brushless’ resolver is the addition of a rotary transformer. The transformer allows the lead wires to exit from the stationary element that enables the resolver to rotate mechanically 360 degress. This eliminates the need for slip rings and significantly reduce costs.

Housed Resolvers: These can be mounted in a custom housing with a shaft, bearing and cover. Typically these options offer a ‘plug and play’ feature not found in pancake resolvers.

Click to see range now available through Aerco

The Geeks at Aerco are happy! At last a great alternative to Piezo Switches have been manufactured by ITW badged as ACTIVE METAL. These are ‘intelligent switches’ and the basic principle is that a material capable of supporting shear and torsional waves at ultrasonic frequencies can have those waves trapped or localized by contouring its surface. These trapped energy regions are set into motion with transducers and act as high quality resonators.
This will operate through a panel thickness of + 0.5″ and can be used through Aluminium, Stainless Steel, Plastic, Glass, are self diagnosing, self adapting, error reporting. These can bet set to be pressure sensitive,  momentary, latching, timed, slide action activated.
Due to the switch being completely sealed, with no moving parts the life cycles are virtually unlimited. So far this has been tested to 100+ million cycles.
Has anyone any suggestions (however crazy) for applications?

But this has caused difficulty for many equipment manufacturers for whom reliability is extremely important. Pure tin can suffer from the phenomenon known as “Tin Whiskers“. electrically conductive, crystalline structures of tin that sometimes grow from surfaces where 100% pure tin is used as a final finish. This is not a new phenomenon and was recognised as a problem back in the 1940s and since then numerous electronic system failures have been attributed to short circuits caused by tin whiskers that bridge closely-spaced circuit elements maintained at different electrical potentials.

For this reason manufacturers who are very sensitive to reliability issues cannot use pure tin finishes; they need either to be able to access non-RoHS compliant product with lead (where their applications are not subject to the RoHS regulations) or to use an alternative plating material. For many of our customers Gold plating has been an acceptable alternative, though it is more expensive.

At Aerco we have developed a system that identifies which products contain pure tin plating and which do not, so that we can ensure for our customers that, where required, the product they are buying is free from pure tin. It is a big administrative workload as Aerco manages over 20,000 products. We are recording this as part of our RoHS programme. If you need further advise on pure tin issues contact us at sales@aerco.co.uk