An idling system is disclosed for devices such as internal combustion engines having a speed controlling or governor. When no load is sensed by a load sensing means, a disable means generates a disable signal to deactivate the engine's speed controller after a predetermined time delay period. When a load is sensed, the disable means is itself disabled, allowing the device's speed control means to operate the device at the higher governed speed.
The modular, automatic idle down system is plugged in series between the 120 VAC output connector of a generator and the input plug of the load device. One prong of the load's input plug may be received directly in a load sensor, such as a Hall effect sensor. The self-contained modular unit is connectable to the mechanical or electronic governor of the generator's engine. The idling system provides two time delays which delay the idling down of the engine upon initial starting and when the load is removed from the generator. When the sensed load current falls below a threshold value, the idling system generates an output signal, after the predetermined time delays, to override the engine's mechanical or electronic governor. The speed-of the engine is thereby reduced from the governed speed to an idle speed.
A system for controlling a fueling governor for an internal combustion engine includes a fueling governor responsive to a throttle command value and current engine speed to produce a fueling signal for supplying fuel to the engine. The governor defines a droop value corresponding to an engine speed difference between a no-load fueling condition and a full-load fueling condition for any constant throttle command value, and also has a gain value associated therewith defining a responsiveness of the governor to changes in the throttle command value to effectuate corresponding changes in engine speed via control of the fueling signal. In one embodiment a control computer is operable to modify the droop value as a function of one or more engine and/or vehicle operating conditions. Alternatively or additionally, the control computer may be operable to modify the gain value as a function of one or more engine and/or vehicle operating conditions.
The low cost speed governor for internal combustion engines may be completely powered by the ignition coil. The governor receives a periodic signal from the primary ignition winding that is indicative of the actual speed of the engine. A pulsed speed signal is generated that is functionally related to the periodic signal. The pulsed speed signal has a pulse width that is functionally related to the actual engine speed. A pulsed reference signal is generated by a timer circuit, and has a pulse width that is functionally related to a predetermined reference speed. The pulsed speed signal is then compared with the pulse reference signal by a comparator circuit, and a pulsed error signal is generated that has a pulse width which is functionally related to the difference between the speed signal pulse width and the reference signal pulse width. The speed of the device is then changed by a transistor bridge network as a function of the error signal. The speed is changed using a reversible DC motor connected to the engine throttle through a gear reduction system. The electronic governor may also include a delay circuit which delays the operation of the governor when an underspeed condition occurs during engine warm-up. Another optional circuit in the governor limits the changing of the engine speed when only a slight underspeed condition exists, to prevent unnecessary cycling of the engine speed.
