ELECTRONIC ENCLOSURE DESIGN

What is an enclosure?An electrical

enclosure is a cabinet for electrical or electronic equipment to mount switches, knobs and displays and to prevent electrical shock to equipment users and protect the contents from the environment.

Enclosures

Mechanical

Electrical/

Electronic

Classification of enclosures

Why do we need enclosures?Protection from dust,

EMI/RFI, moisture, human interference, shock, thermal stress, ingress of solid foreign objects.

Where used? Enclosures are used in places

where protection against flammability, unwanted radio emissions, resistance to damage from fungus, static electricity, heat, pressure, humidity, condensation drips, vibration, radiation and other environmental measurements is required

Enclosures are used in military, telecom, missiles launchers.

They are designed according to applications and used on land (ground vehicles, heavy machinery), in air (aircrafts), in sea (marine junction box ,etc.)

What was the project?Airborne electronic

enclosure for generic application was designed.

The project was targeted to learn the basics for designing an enclosure.

Design concepts, material selection and fabrication method

Some design concepts were studied and out of them, one was chosen on the basis of cost per unit and manufacturing time.

Al-6061-T6 was selected as this was predominantly used in aerospace applications.

CNC Machining was chosen as fabrication method as this reduces need of other operations and nuts at various places as per the design concept.

Features used• The ribs were provided for

strengthening the base plate and a mechanical stoppers for guiding the adjacent plates.

• Slots have been cut on external faces with large surface area for cooling.

• Extrude bosses with tapped holes have been created on the plates (inside) wherever fasteners have to provided, these remove the usage of nuts and washers.

AssumptionsThe enclosure was

designed with an assumption that two PCBs would be placed inside, two input connectors and two output connectors.

The heat load on each PCB would be in the range of 8-10W.

The heat generated inside the enclosure would be dissipated by conduction and convection.

Modelling and drafting of enclosureThe enclosure was

modelled and drafted using SolidWorks 2011 .

Some of the standards like DO-160 and ARINC-600 were followed to design the enclosure.

2D drawings give information for the manufacturer.

Questions?

Thank you!