Good Day All:

    I am wondering if anybody has any advice regarding a way to save
data in non-voltile memory upon the loss of power.  My circuit utilizes
solid state relays which have no latching capabilities.  In the event of
power failure I wish to save their last state (closed or open) so that
when power returns all can be restored .  Cost and lifetime prohibit
battery back-up and writing to EEPROM every cycle would wear it out.
    I thought the best way would be to detect the power going out and
with the last breath write the relay states.
    Currently,  I am using a 16C84 but probably could get by with a
12CE518 or 12CE519 for the actual application.   I would appreciate any
input anybody would have regarding this circuit, specifically on a
reliable way to detect the power drop off.  I am using a power supply
with a transformer (120 VAC to  15 VAC), full wave rectified, filter
cap., and voltage regulator.   Thank you all.



                            Best Regards,
                            John Reasoner
                            Solid State Instrument, Inc.
                            reasoner@pcisys.net