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Amphibionics 04 3/24/03 8:23 AM Page 66
Amphibionics
11. Finally replace the top servo cover and secure it in place with
the four screws that were removed during step 2. When the
cover and screws are replaced, the servo should resemble the
one shown in Figure 4.17. Be sure to mark the servo, indi-
cating that it has been modified, since it will look exactly the
same as an unmodified servo.
FIGURE 4.17
A servo modified for
continuous rotation.

Controlling a Modified Servo

A modified servo is controlled in the same way as an unmodified
servo. The only difference is that when the pulse width signal is
sent to the servo, it will start turning the motor in the required
direction and will continue to rotate as long as the signal is
applied. Since the potentiometer that keeps track of the output
gear position has been removed and replaced with the resistor
network, the internal circuitry will think that the motor has not

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