Nitro Governor - with separate control channel
When the nitro Governor mode is used, the throttle servo can be controlled entirely via the throttle channel of the remote control as long as the Governor function is switched off. This is especially necessary to start and warm up the engine as well as to stop the engine after the flight. Only when the Governor is switched on, the system will take over control of the throttle servo to spool up the rotor to the desired speed (if this is not yet reached) and ensure that the rotor speed is maintained during the flight. As some model engines react very sensitive in the lower throttle sector and abrupt engagement can cause the engine to quit, i.e. when the clutch is not fully engaged and/or the rotor is not yet turning, also the manual throttle control can be of advantage. The pilot can run the engine to speed "by hand" before control is passed over to the Governor.
The adjustable rotor headspeed range in "nitro" mode is 2500rpm/min. The lowest head speed to govern is 500rpm/min, the maximum head speed is 3000rpm/min.
When a separate control channel is used for the Governor function the throttle servo can be controlled as usual via throttle channel and throttle curves of the transmitter. By switching the separate control channel in different positions, the Governor can be activated and the desired rotor speed can be preset. Note that for safety reason the throttle channel has priority over the Governor control channel as long as the output is below 25%. So you can always control the lower throttle servo positions by hand, even if the Governor is already switched on by the separate control channel. Only when the throttle is raised above 25% the Governor intervenes and controls the throttle servo to spool up and maintain the rotor head speed. So when you want to bring the throttle servo to idle position for autorotation or to shut off the engine you can always do this, regardless of how the Governor is set at the moment. In respect to this please note that the AR7210BX will be set to Autorotation bail out mode if the Governor was activated once and the throttle channel is brought back below 25%. Now when throttle is increased again, the Governor will speed up the rotor faster than on initial spool up! Therefore if you make a stopover and the rotor is completely stopped, you must completely disable the Governor once with the separate control channel. So the Governor is reset and will perform an initial startup again. Otherwise Autorotation mode would still be active and may cause the helicopter to tip over due to the abrupt speed up.
(scale depending on transmitter)
(= Manual control)
red or blue
(= RPM control)