Doosan DX225LC, Manual, Page: 15 / 136

Electrical System SP000935
Page 14
After Start
Once the engine has been started, the belt driven alternator (10)
generates a current.
The output generated by the alternator (10) is a square wave
pulse voltage through the "P" terminal and the frequency of the
pulse voltage is proportional to the rotation of the alternator.
The starter controller (7) monitors the frequency of the output
current. Once the frequency is equivalent to 500 rpm, it is
sensed and the connection between "S" and "E" terminals and
the connection between "B" and "PP" terminals are opened. As
a result the rotation of the starter (9) is stopped. Once the
engine is running, the starter (9) will not operate even if the
starter switch (5) is moved to the start position, preventing
possible damage to the starter.