Page 78 - Build a Remote Controlled Robot

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POWER SUPPLY AND TEMPORARY CONTROL BOX
of trying to solder the connecting wire to the battery post, I
elected to use what is called a crimp kit. A crimp kit enables
you to attach special ends to the wires that allow them to be
wired together easily. Figure 3-6 shows the different ends
available and the crimping tool.
As illustrated in Fig. 3-7, the batteries are not only wired
together but to other components. Two of these are charging
plugs that come with the batteries. Also wired between the
two batteries is an SPST (single-pole, single-throw) switch.
This switch serves two functions: First, it is the main on/off
switch for Questor; and two, it separates the batteries when
they are being charged (the switch is in the off position at this
time). Make sure that you use lengths of wire long enough to
allow the charging plugs and switch to reach the rear of the
platform where they will be mounted later; for now you can
tape the components securely to the platform.
Once you have wired the platform, use the charging plugs
and charge the batteries. While the batteries are charging, it
takes about 36 hours, you can construct the temporary control
box used to control Questor.

TEMPORARY CONTROL BOX

Before you begin to assemble the temporary control box, a
brief explanation of how it functions is in order. To begin, the
two 6-volt batteries have been wired together to give Questor a
12-volt power source. This power source is then wired to two
potentiometers, one for each motorized wheel, within the con-
trol box. These pots as they are commonly called, are a type of
variable resistor that lowers or raises the voltage coming from
the batteries. The pots are used to control the speed of each
motorized wheel.
The lowered or raised voltage passes into two double-
pole, double-throw (DPDT) switches, again one switch for
each motorized wheel. The DPDT switches are actually two
switches in one, hence the term double in their description.
To reverse the direction of a dc electric motor, you must