the original vision
many small boxes that can sense motion, be
moved around freely by participants, and make sounds in response to
motion. the boxes fit into the sides of four fixed stairstep
structures, which participants can climb on. the structures also
contain motion sensing and an electric eye perimeter.
what got created
10 wooden cubes, each about 1.5 feet to a side,
with battery powered motion sensing and EL-wire on the edges. one
cube has a siren in addition to the EL-wire. also, four 8 foot cube
frames with a 4 foot eyeball suspended in the center and motion
sensing unit above, connected to EL-wire taped to the front of the
eyeball.
how it works
a quick overview: motion sensors designed for
home security are modified to run on battery power. they then become
a switch for any other circuit. in this case, the circuit is either
EL-wire or a siren.
start with the basic sensor
circuit. strip off the diode bridge that converts AC to DC, and
remove the relay (since it has a 24v coil that we don't want to
power).
add on a transistor circuit to
amplify the output signal. this is tricky because the output is
active-low, so you have to use a PNP transistor in the emitter
follower circuit.
make a bunch!