What device is used to measure speed in an Electronic-Hydraulic Governing system?

In an Electronic-Hydraulic Governing system, the primary purpose of the governing mechanism is to maintain a constant speed of the engine or turbine under varying load conditions. To accurately measure this speed, a sensor that is robust and can provide real-time feedback is essential.

A permanent magnet in this context functions within a magnetic sensor that detects rotation. When connected to a magnetic pickup coil, the movement of the magnet as the engine or turbine rotates induces an electrical signal, which correlates to the speed of the machinery. This signal can then be processed electronically to maintain the desired speed of the system through the governing control.

While optical sensors and digital sensors are also commonly used in various speed measurement applications and can provide accurate speed readings, the specific context of the Electronic-Hydraulic Governing system makes the use of permanent magnets particularly suitable due to their reliability and integration with the magnetic sensing technology. They create a simpler and sometimes more rugged setup, which can be beneficial in the challenging environments often found in power engineering applications.

Mechanical dials, while they can also provide speed information, are less common in modern electronic systems as they lack the precision and quick response needed for effective governing.