Movable barrier operator

DETAILED DESCRIPTION A movable barrier operator having an electric motor for driving a garage door, a gate or other barrier is operated from a source of AC current.
The movable barrier operator includes circuitry for automatically detecting the incoming AC line voltage and frequency of the alternating current.
By automatically detecting the incoming AC line voltage and determining the frequency, the operator can automatically configure itself to certain user preferences.
This occurs without either the user or the installer having to adjust or program the operator.
The movable barrier operator includes a worklight for illuminating its immediate surroundings such as the interior of a garage.
The barrier operator senses the power line frequency (typically 50 Hz or 60 Hz) to automatically set an appropriate shut-off time for a worklight.
Because the power line frequency in Europe is 50 Hz and in the U.
S.
is 60 Hz, sensing the power line frequency enables the operator to configure itself for either a European or a U.
S.
market with no user or installer modifications.
For U.
S.
users, the worklight shut-off time is set to preferably 41/2 minutes; for European users, the worklight shut-off time is set to preferably 21/2 minutes.
Thus, a single barrier movement operator can be sold in two different markets with automatic setup, saving installation time.
The movable barrier operator of the present invention automatically detects if an optional flasher module is present.
If the module is present, when the door is commanded to move, the operator causes the flasher module to operate.
With the flasher module present, the operator also delays operation of the motor for a brief period, say one or two seconds.
This delay period with the flasher module blinking before door movement provides an added safety feature to users which warns them of impending door travel (e.
g.
if activated by an unseen transmitter).
The movable barrier operator of the present invention drives the barrier, which may be a door or a gate, at a variable speed