Redundant power supply for VME card cage

the topic here for blog is the use of hot swap redundant power supplies in VME 64x/cPCI card cages.

The card cages can be:

Commercial

Industrial

Miltary rugged.

All the above 3 types require different type of power supply. The selection of power supply depends up on the form factor and input supply needs. The most popular amongst these are P47 connectorised power supplies. thes eare plugable ones and can be arranged in as hot swap N+1 redundat mode.

There are some taiwanese companys making good plug in N+1 redunadant power supplies.

If Dc input is the need we can configure the VME power supply with 4 DC-Dc converters.

Selection of input filter to meet stringent EMI standard for the Military is anoyther big challenge.

EMI STANDARD MIL-461

The emission standard for the miltary equipment is different from the normal commercial norms.

There is a diffrent standard called 461 standard for the military electronic equipment.

The evolution of this standard started from 461A and now is being reviewed for 461F.

There only few test facilities available in India to test for 461 standards. Few of them are:

1. SAMEER
2. RCI
3. LRDE
4. WIPRO

Setting up of a certified lab to conduct these test facilities will be an ideal business proposition in India looking at its defence spending and new product requirements.

Light weight material for avionic racks

Any flying object or aircraft require weight advantage to carry more fuel. Al alloy has been majormaterial for all the units so far in avionic industry.

Are there any alternative materisl with lesser weight?

Magnesium is NO inside the aircraft. What about composites ot polycarbonates?

Did any one tested fthese matersils?

Where can we get a good info on selection of shock mounts?

What are the use of tie rods?

Casting

How do we do castings?

Different types of castings.

We are lookin for gravity casting people in Bangalore/India

How to make IP68 enclosures

IP 68 sealing is important for military computers and other units.

The usage of right type of gaskets and sealants are required.

The important aspect is how to water seal the cable glands and connectors.

there are hermitically sea;led connectors available.

How to wire VME backplanes

Rear wiring of VME back plane is a tricky business.

We can use one out of the following:

1. Berg connectors
2. 5 row connectors
3. wire wrap
4. Sandwich PCB with edge connectors.

Any other technique available please let me know.

Avionic racks

How to design a avinic rack?
The main feature required are weight and accoustic proofing.
Can we use 6061 alloy inplace of 2024 alloy?

What are the design creiteria to be adhered?