Hardware Reference
In-Depth Information
Figure 2-2:
Removing the
case of the
movement
mechanism.
Try and identify how the wires are connected to form the circuit. Find the terminals on the
power switch. These may be covered with glue, but this can be carefully peeled or scraped
away. In many cases, there will be only two wires going to the switch; if there are more, then
the wiring is more complex, and it may be better to hack a different model if you cannot eas-
ily identify how the circuit works.
Series and Parallel Circuits
Series
and
parallel
are two names to classify how components in a circuit are connected. In
series, as the name suggests, the electric current flows through all the components in a
series, one after another. As such, if you have switches wired in series, then all of them
have to be closed for the current to flow. Breaking one of them will break the circuit.
In parallel, the flow of electricity splits and so closing any switch wired in parallel will allow
the current to flow. This is because electricity tends to take the path of least resistance, and
in this case, when the relay contacts close it has a much lower resistance than the almost
infinite resistance of the open switch.
