FIELD OF THE INVENTION
The Test Jig is used to perform the testing of hardware of control unit of Solid State
flight Data (SSFDR). Control unit is a part of the SSFDR, which provide the interface
between the Recorder Unit and user. The test jig provides simulated field signals to test the
wiring and various hardware used in the control unit.
BACKGROUND OF THE INVENTION
The Control unit is a sub system for Solid State Flight Data Recorder (SSFDR). This
unit contains a Microphone Preamplifier Board assembly, head set jack, ERASE and TEST
pushbutton switches and the test result indication for monitoring and bulk erase the memory
remotely. It provides the interface between user and SSFDR. Control unit consist the two
circular connectors, out of which one is connected to the SSFDR for exchange of the signals
whereas another one is used for downloading purpose. It is used to perform the following
functions on SSFDR.
• Provision for hearing live audio through audio jack
• Status of Recording of data and audio in SSFDR
• Fault Indication of Filght Data Recorder (FDR)
• Fault Indication of Cockpit Voice Recorder (CVR)
• Bulk Data Erasing.
• Setting of Replay Mode
• Downloading of the data and audio recorded in SSFDR
SUMMARY OF PRESENT INVENTION
In accordance with the design and development Test jig for control unit, it is used to
verify the hardware functionality of the control unit. It is a small test jig with aluminum casing
consisting the number of monitoring points, push button and LED indicators.
BRIEF DESCRIPTION OF THE DRAWINGS
The features and advantages of the present invention become more apparent and
descriptive in the description when considered together with figures/flow charts presented:
Figure 1: is a Block Diagram Test Jig for Control Unit.
Figure 2: is a Block Diagram Control Unit connection with Test Jig.
DETAILED DESCRIPTION
Test jig simulate the different control signals/logics to test the control unit. The push
button provided on the front panel of the test jig generates the control signal (+28V GND),
which is routed to the control unit through the loom. The indicator (LED) on the control unit
are pulled to the +28V DC which start glowing as soon as the signals from the test jig is
reached to the control unit. The glowing LEDs of control unit on getting the signals from test
jig indicate the health of the LEDs mounted on the control unit. If any LED does not glow it
means that the particular LED has gone bad and needs to be replaced.
Test Jig consist the port where microphone input can be can be connected. The
microphone input is amplified by the amplifier circuit mounted on the PCB of the control unit.
The amplified output of the circuit is routed to the SSFDR for recording in the protected
memory module of the SSFDR. There is the provision to monitor the amplified output of the
microphone on the monitoring panel of the test jig. Audio tone can also be simulated by the
test jig to test the audio channel of the SSFDR. The procedure developed to test the control
unit using test jig is described below:
MIC Audio Test:
• Connect the + 12VDC supply at the terminal of the test jig.
• Feed some audio signal through area microphone at the MIC input terminals
• Check the amplified audio by listening through head phones at MIC output terminals
on the test jig.
MIC Amplification Test:
• Connect the + 12VDC supply at the terminal of the test jig.
• Feed some audio signal (20mVp-p), 1KHz) through area microphone at the MIC
input terminals
• Check the amplified audio output with gain of 100 on MIC out terminals of the test jig.
LED Test:
• Connect the + 28VDC supply at the terminal of the test jig.
• Press and hold the pushbutton of Fault Induction signal on the Test Jig and check
the LED ON (Green) on the control unit.
• Release the Pushbutton and check the LED OFF on the control panel.
Push button test (Test and Erase):
• Connect the + 28VDC supply at the power supply terminal of the test jig.
• Press and hold the pushbutton of TEST signal on the control unit.
• Check the TEST LED ON (Red) on the Test Jig.
• Release the push button
• Check the TEST LED (OFF) on the Test Jig.
• Press and hold the push button of ERASE signal on the control panel. Check the
ERASE LED ON (Red) on the Test Jig.
• Release the push button
• Check the ERASE LED (OFF) on the Test Jig.

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. The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. Test Jig for testing of control Unit of SSFDR comprising; SSFDR means Solid State Flight Data recorder which records the flight data for use of crash investigation and health of the Aircraft; Control Unit means is a sub-system of SSFDR mounted separately. It provides the controls for the SSFDR and it has facility for amplifying the MIC input signal, Self-test and facility for erasing voice data of previous flight when it on ground.

2. Test Jig for testing of control Unit of SSFDR of claim 1 wherein the design of the Test Equipment is based on third party USB chassis with hot swappable relay modules.

3. Test Jig for testing of control Unit of SSFDR as claimed in any of the preceding claims wherein a Graphical User Interface (GUI) developed using Lab-View programming language to simulate and to carry out the functional testing of SSFDR.

4. Test Jig for testing of control Unit of SSFDR as claimed in any of the preceding claims wherein the procedure and setup as described in specification has been exclusively developed to generate 50ms power interruption and verify the effect of the power interruption on the SSFDR functionality.

5. Test Jig for testing of control Unit of SSFDR as claimed in any of the preceding claims wherein user can simulate power interruption for the duration ranging from 10ms to 1000ms simply by entering the value of time duration required.
,TagSPECI:As per Annexure-II