(...) No, the servo needs power to the + and ground terminals to drive the motor to the setpoint indicated by the signal wire. If I don't invert the signal there is no power for about 30msec and only 1 or 2 msec ov voltage on the motor port. By (...) (25 years ago, 12-Feb-00, to lugnet.robotics, lugnet.robotics.rcx.pbforth, lugnet.robotics.rcx)
(...) I should add here that no external power source is necessary to drive the servo. This is important since a micro or miniservo and an SMT version of the driver can be made to fit INSIDE a space similar to a worm gear box (6588 in LDraw). I'm (...) (25 years ago, 12-Feb-00, to lugnet.robotics, lugnet.robotics.rcx.pbforth, lugnet.robotics.rcx)