R001.HTM

RME325 Contactor Timer

Form/Fit/Function matches the original board design (G136808)

This new design has additional features as well as a backup timer.

Utilizing a microcontroller, core-memory, pre-contacting 'bump' and component failures are all addressed.

Additional Features:

2 led are incorporated in the design.

A 1 hz LED, shows the processor is running.

A 'Manual Time Stop' LED, lights when the 'start timer' signal is lost (manually interupted) before the timing circuit has timed out.  Also, the audible signal is pulsed 2 times at end of exposure to give an audible indication of manually stopped exposure).

If the Time stop (timing circuit) or Phototimed stop signals are not in the proper state when the start signal is applied, then the 2 LED's are flashed in unison to indicated no exposure is permitted (component failure).

Timing Circuit failure:  If the backup time is reached, then the 2 LED's are flashed alternately to indicate backup time.

Test Switch:  Mounted on the board is a test switch to activate the 'Start' input and provide a pull-up for the timing circuit.  This allows for easy trouble shooting of the timer contactor board.

Exposure errors are cleared at the next 'Start' signal.

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