About the 9905-134
Modeled by Woodward INC, the 9905-134 model is one of the electronic speed control units. This model is a reverse standard speed control in the 2301A series. This model has two supply voltages that can be used depending on the chosen application, 88-131 Vac or 90-150 Vdc. The speed control model can be used in isochronous mode with steam or gas turbine and or gas or diesel engines, often referred to as prime movers. The isochronous mode is often used to aid the prime mover in keeping consistent speed so long as the load is being provided; isochronous mode can also be used with Woodward load sensors. The isochronous mode also features an external droop; the external droop is used for speed control as the load function when the attached prime mover is operating with two or more prime movers or on an infinite bus.
As a reverse-acting controller, the 9905-134 model can operate with a variety of Wodwawrd EGB actuators or governors. In a reverse-acting system, when the current of the actuator decreases, the system will call for more fuel; when the signal to the actuator is completely lost, the system will drive the actuator to full fuel; when this occurs, it allows the backup mechanical ball head governor to take complete control rather than shutting down the prime mover, which occurs in a forward/direct-acting system.
When wiring the 9905-134 model, all wirings are interchangeable between the direct-acting and reverse-acting controls. While the wiring is the same, it is required that changes be made to the attached printed circuit board if a control is needed to operate an actuator opposite the system. For more information on the 9905-134 control, refer to any available documentation for electronic speed controls or the 82020C Instruction and Operating Manual.