Electronic Speed Governor
An electronic governor continuously measures engine speed with a sensor and drives the fuel actuator by comparing the measured speed with the setpoint. It gives far tighter regulation than a mechanical governor; droop is optional, and zero droop, that is isochronous operation, is possible.
A typical electronic governor has three parts: a speed sensor (a magnetic pickup reading the flywheel teeth, or the alternator W terminal), a control board and a fuel/throttle actuator. The board calculates rpm from the pulse frequency, finds the error and produces an output to the actuator. Gain, stability and droop parameters are adjustable.
- Load acceptance is better: on sudden loading the speed drops less and recovers faster.
- If the sensor signal is corrupted the system cannot know the speed; for this reason the signal cable is run shielded and the pickup gap is set correctly.
The distinction matters: throttle position control and speed regulation are not the same thing. The GS740 and GS740-3P drive the position of the throttle lever and do not measure engine speed; the GS740-3P's closed loop is on actuator position. Real speed regulation requires feedback that reads speed.
Context in which this term is used: Electronic speed and throttle control on a diesel engine