FIELD OF THE INVENTION
The field of this invention is backplane modules used in the aircraft avionics HMI systems to
provide communication interface between the modules of the system. The backplane also
provides interface for external signal reception and conditioning of those signals.
BACKGROUND OF THE INVENTION
The aircraft systems have various requirements such as environmental lightening protection,
compact space, severe environmental conditions such as high temperature and low
temperature. To meet these space and environmental features the system needs
backplanes with flexi rigid design and lightening protection.
SUMMARY OF PRESENT INVENTION
In accordance with one aspect of present invention is to provide a inter-communication
interface between the modules of a airworthy system.
In accordance with second aspect of present invention is to provide a suitable flexi-rigid
backplane for low space requirements inside a airborne system.
In accordance with another aspect of present invention is to provide a backplane with level
4, and level 5 lightening protection.
In accordance with yet another aspect of present invention is to provide a low voltage and
high current capacity source for the electronic modules.
In accordance with yet another aspect of present invention is to provide a low voltage and
high current capacity source for the electronic modules.
In accordance with yet another aspect of present invention is to provide a interface for the
front end of the Human Machine Interface.
Annexure‐II
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1: It shows the backplane Layout.
Figure 2: It shows the block diagram of signal flow in the backplane.
DETAILED DESCRIPTION
The human machine interface (HMI) in the aircraft avionics system is used as a control and
display between the pilot/copilot and the control system/sensor of the aircraft. The old
cockpit design which was based on analog instruments to provide the pilot with the
information of aircraft’s critical parameters was complex in nature and it was difficult for the
pilot to maintain the situational awareness while monitoring all the analog panels.
The latest glass cockpits utilize the HMI concept which provides the pilot with the right
information when needed and asked by the pilot. The HMI helps the pilot control and
stabilize the aircraft through the input given with help of buttons and knobs on the HMI panel.
Furthermore the HMI screen displays the aircrafts flight parameters which can be monitored
by the pilot.
The aircraft’s parameter information reaches the HMI system through the sensor and then it
is processed and conditioned by the modules inside the HMI system. The processed and
conditioned parameters are displayed over the front end of the HMI.
The flexi-rigid backplane module’s task is to provide a communication interface for the
processing and signals conditioning module in the Human Machine Interface. The signals
from the aircraft’s various systems comprising of discrete, digital and analog type in nature
are received at the connectors mounted in the PCB of the backplane. The signals are
protected by the inbuilt facility in the connector pin against the EMI/EMC noise and lightening
protection. These signals are routed to the main PCB section where they reach the various
connectors such as power supply connector, HMI front end interface connector and
electronic module connector.
The backplane has the circuit for the low voltage generation which can generate 1.2 Volt and
2.5 Volt signals. The electronic modules requiring low voltage and high current can also be
driven by this circuit element. The circuit can produce up to 3 amperes of current. The main
PCB also has filter modules to protect the signals against the power surge and EMI/EMC
noises.

WE CLAIMS:-
Accordingly, the description of the present invention is to be considered as illustrative only and is for the purpose of teaching those skilled in the art of the best mode of carrying out the invention. The details may be varied substantially without departing from the spirit of the invention, and exclusive use of all modifications which are within the scope of the appended claims is reserved. We Claim

1. The backplane comprises, i) A MIL grade connector interface with level 4, level 5 lightening protection ii) MIL grade Flexi-Rigid Printed Circuit Board iii) Airborne connector interface for electronic modules iv) Airborne connector interface for front end of the HMI v) Airborne connector for power supply module vi) Low voltage generation circuit for 1.2 volt and 2.5 volt with current capability of 3 amps.

2. The backplane as in the claim 1, is capable of interfacing with any 55 pin circular connector based system whether land based, military or airborne.

3. The backplane as in the claim 1, is capable of providing level 4, level 5 lightening protection in a system whether land based, military or airborne.

4. The backplane as in the claim 1, is capable of interfacing any electronic modules of a system whether land based, military or airborne with 122 pin connector.

5. The backplane as in the claim 1, is capable of interfacing front end any Human Machine Interface whether land based, military or airborne with a 50 pin connector.

6. The backplane as in the claim 1, is capable of interfacing DC power supply module of a system whether land based, military or airborne with a 40 pin connector.

7. The backplane as in the claim 1, is capable of generating low voltage power supplies of 1.2V and 2.5V for any electronic modules with a maximum current rating of 3 amperes. ,TagSPECI:As per Annexure-II