Page 88 - Build a Remote Controlled Robot

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REMOTE CONTROL SYSTEM
The switches that the servos trip are called leaf switches
(Fig. 4-2). A leaf switch is a very small on/off switch that is
triggered by depressing a small metal strip or “leaf” on the
switch. By using four leaf switches, it is possible to recreate
the function of the DPDT switches used in the temporary
control box.
A total of eight switches is needed to duplicate the func-
tion of the DPDT switches used to control the robot’s motor-
ized wheels. One servo is then used to trip four switches in
such a way to drive the wheel either forward or reverse. You
use the control sticks on the remote control transmitter in the
same way as you flipped the DPDT switches on the temporary
control box; up is forward, center is off, and down is reverse.
If you chose a remote control system with more than two
channels, you can use the other servos to trip leaf switches for
turning other devices on or off, or control motors (forward,
stop, and reverse) within the robot. The third servo of my
remote control system is used to turn a horn on and off.

TABLE 4-1. Parts List

AMOUNT ITEM

1 2-to-3-channel remote control system
10 Leaf switch and mounting screws
1 10- 10- 1/8-inch plywood square
4 1- 10- 1/8-inch wood strip
4 8-post barrier strip
4 Screw hook
2 Rubber band
1 Small strip of foam rubber
# Spools of 18-gauge black-and-red wire
4 2- 2-inch aluminum corner brace
4 2-inch 1/8-inch-diameter bolt, nut, and lockwasher set
1 4-slot fuse holder
4 SFE 20-amp fuse