raking and bagging up some leaves from his back yard when he got a call from a restaurant
owner in Lubbock Texas. “Lubbock Louie’s” hamburgers was a popular place to eat in
the west Texas town. According to the owner, at times, the place could get quite
busy and noisy. The owner wanted to know if Wily had time to come up with a simple
way to help his waiters know when someone at a table needed service. Wily gave the
request some thought and after some negotiations, he agreed to take on the project.
The owner thought some kind of flashing
light would work. A battery powered device, which when activated would flash some
lights. The lights needed to be bright enough to be seen from across the room.
They needed to turn themselves off and operate for some time before any batteries had to
The circuit which Wily came up with
is shown below. A single 3v lithium coin cell battery powers the device. Four super
bright green LEDs are flashed when the assembly was rotated into the “Requested Service”
position. A tilt switch senses when the device is in that position. A simple timer
turns off the flasher after 3 minutes, if left in the flashing position.