Check the manufacturers spec sheet.
Often a temporary voltage overload is permitted provided that the
temperature is within bounds and the ripple current is low.

However, your 15V under load - how is it measured? If you are measuring it
with a DVM then the peak voltage may well be exceeding the 16V rating under
high ripple conditions. This is almost certain to cause premature  failure.

If you can look at the voltage with a 'scope you should be able to get an
idea of the actual max. voltage.

The "16V" rating will have some safety margin - but I would normally run at
50% to 70% of rating - somewhat dependent on temperature, ripple and
manufactureres data sheets.

Richard P



>>>>>
15V      .------.
-----o---| 7812 |---o----> 12V
     |   '--.---'   |
    _|_     |      _|_
    _ _470uF|      ---  104 cap
     |      |       |
    _|_    _|_     _|_


The input Cap I am using is EL Cap 470 uF (16 V), the input voltage is
DC
19 V (unloaded) and loaded is around 15-16 V. My question is what will
happen theoretically to the EL Cap if the input voltage is higher than
max rating of the Cap. Currently the circuit still functioning without
problems.

Thanks.
>>>>

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