Instead of flashing lamps, I'd like to use dual or quad 555 timer chips
and power MOSFET drivers to flash the chest and brain lights. The timers would
be set for slightly different rates to give a somewhat random appearance.
With this setup, you can control both the duty cycle and speed of the
flashes. By putting OR gates between the timer outputs and the drivers you
can also make everything light up at once, if you desire. The door is then
left open for more complicated microprocessor control at a later date.
I'm experimenting with tiny pager motors and Pulse Width Modulation (PWM)
speed control, to see if this setup would be suitable for rotating the ear
sensors. If that doesn't work out, I also have some tiny stepper motors
designed for 3.5" floppy drives, but their 18 degrees per step may make the
sensor motion too jerky.
If the pager motors and stepper motors don't suit for direct drive,
I have a couple of disposable dental prophy angles to install in the ears,
to provide a right angle gear mechanism. The drive motors can sit in the
radar section.
I'm planning to install actual lighted alternate action pushbutton switches
behind the chest buttons. For starters, the lights could be on constantly,
but eventually I may make the option to turn them off and on. I have my eye
on the NKK switches, switch body DLB2145W01, white square cap AT419B and a
T1-3/4 14V midget groove base lamp (Chicago Miniature #386). The switches
will control various functions including crown/light rod rotation, radar
section rotation, torso rotation and sound.
I'd like to give the arms some mobility, and eventually motorize them as
much as possible. I'm collecting a bunch of hardware to experiment with
including drawer slides for forearm motion and support (in and out),
door hinges for side-to-side motion and desktop lifters for up-and-down
motion. To fasten and support this mess securely, I'm building an aluminum
"endoskeleton" from right-angle and flat stock to be assembled inside the
torso.
For the mechanical background sounds, I'm thinking about building a board
around a ISD "Chipcorder", model ISD1416.
This is a digital record/playback unit which samples at 8Khz and can be set to
loop samples. I would record the background soundtrack into the chip, and
have it mix into the sound system, but not through the neon feed.
I ran across a couple of interesting articles about how to modify a
standard RC servo to run a large DC motor by adding a power MOSFET
H-Bridge and moving the position feedback pot. I may take a whack at
building a couple of these "super servos" to implement fully proportional
rotation and positioning for the radar section and torso.
