Spektrum SPMAR7110 - Handbuch (Seite 17)

17
EN
RevLimit Instructions (AR7110R only)
The Spektrum AR7110R features an integrated RevLimit limiter. The RevLimit func-
tions as a digital rpm limiter preventing the main rotor from over-speeding. When
the rotor speed is at or below the programmed rpm, throttle position is controlled
via the radio (i.e. throttle curves). The RevLimit only engages when the rotor rpm
exceeds the programmed rpm reducing the throttle position preventing over-speed.
The RevLimit limiter is designed to limit engine speed between 9,500 and 20,500
rpm. Engine rpm = Rotor rpm * Main gear ratio.
Servo Requirements
All common three-wire servos (analog and digital) are compatible and can be used
for the throttle servo. Note that two throttle channel outputs are available: unregu-
lated and regulated. The unregulated throttle operates at the battery voltage. The
regulated throttle is regulated to 5.2 volts and is to be used when a high-voltage
compatible servo is not being used for throttle control.
Connections
The RevLimit is totally integrated and the target rpm is adjusted via the Gear cha-
nnel (channel 5). The only external connection needed is to mount the backplate
rpm sensor to the backplate of your engine using two backplate screws. Note
that the rpm sensor mount has two positions: extended for .90-size engines and
retracted for .50-size engines. When installed correctly, the rpm sensor should just
contact the backplate. On some engines and specifically the YS .50 and .90, the
sensors must be spaced .5 to 1mm from the backplate. No additional magnets or
brackets are needed. The rpm sensor picks up the magnetic effect of the crankpin
as it passes the rpm sensor.
If your system is not limiting RPM in flight, re-position the sensor .5 to 1mm away
from the backplate. This can be easily accomplished by loosening the 2-56 button
head screw on the sensor mount, re-adjusting the position, and then tightening.
This should resolve the issue.
Install the servos in their appropriately labeled ports. The throttle and gear channels
have two outputs. Output 1 is unregulated and the pack voltage is provided at this
port. Throttle and Gear outputs 2 are regulated to 5.2 volts when a throttle servo
and gyro are used that are not compatible with high voltage. Most gyros require
less than 6 volts.