Test Procedure for 909888.

Equipment.

1mm spring loaded test jig.

1 off cable adaptor.

1 off Mistral Test Unit

1 off Test PC with Mistral software installed.

System other than test jig (interchangeable) is set up permanently as main membrane switch test unit.

System settings.

Isolation test scan – High voltage scan 18V @ 10 MΩ.

Switch loop resistance - < 100Ω typical.

Permanent connection - < 100Ω typical.

LED current set - 10mA

Forward LED voltage - 1.0V to 4.0V @ 10mA

Reverse LED leakage - 5.0V @ 100uA.

Typical Test

 

Test Procedure.

1. Set up test equipment as required and load program (see fig 1).

Fig 1.

2. Enter job details and start test program. Place unit to be tested in test clamp. Note that the clamp uses rounded spring loaded pins to avoid any damage to the tail ends.

3. Press space bar to initiate test. Test system will carry out an initial scan for the following:

• Scan for any short circuit between all programmed lines.
• Scan for any permanent connections (if applicable).
• Scan for any isolation points (if applicable).
• Scan LED’s – checks that they are fitted and to the correct polarity.

4. The LED’s are then illuminated in sequence and will continue to cycle until space bar pressed to terminate test.

Operator will visually confirm that LED’s illuminate in the correct colour.

The voltage require to drive the LED’s at 10mA is displayed on the PC, see fig 2.

Fig 2. Initial scan and LED test complete.

5. After LED test terminated operator is prompted to press each switch to confirm correct function. This will indicate the switch loop resistance and also detect any open circuit fail on the switch lines (if occurred). See fig 3 and 4.

Fig 3. Part way through switch test

Fig 4. Switch test completed.

6. Operator will press spacebar to confirm all switches function. If any switch fails to operate the test will not be allowed to complete.

7. Operator will remove passed unit and fit next to be tested.

8. Repeats test cycle until all units tested.

9. If a unit fails the initial scan or subsequent function test the unit will not be allowed to pass. If during the initial scan a fault is detected the affect switches and/or LED’s will be immediately highlighted in red. Also an indication of the fault mode will be displayed. See fig 5).

Fig 5 – Test failure example.

10. Production order is 100% function tested prior to sending to despatch.

11. Any reject units will be isolated and tagged. Failure mode will be confirmed by engineering as required and any corrective actions carried out.

 

Manufacturing Eng

22/04/09