Bailey Moyes 912 Dragonfly, Руководство по обслуживанию

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An external switch may also be used to manually select which ignition system provides the tachometer
source. Since magneto problems can often be detected early on by erratic tachometer readings, an
external switch allows the pilot to choose which magneto is to be monitored, allowing him to choose a
different mag on each flight, and thus providing some monitoring of the health of each magneto. A
switch can be wired to choose which tachometer output is provide to the EIS tachometer input #1 (as
shown on the tachometer wiring diagram), or alternatively, an on/off switch can be wired inline with
tachometer input #1. This switch can be opened to force the EIS to use tachometer input #2.
7.6.2 Tach Connections to Lighting Coils (Jabiru, Rotax, and others)
When the tachometer connection is made to the lighting coil, typically 1/2 as many pulses will be
generated, as there are poles in the lighting coil. (For 3-phase electrical systems, 1/3 as many pulses as
there are poles in the lighting coil.) For CDI-equipped Rotax Engines, 12 magnets are used,
generating 6 pulses per revolution of the engine. For non-CDI type Rotax engines, 2 pulses per
revolution is generated. Jabiru 4-cylinder engines generate 5 pulses/revolution, and Jabiru 6-cylinder
engines generate 4 pulses/revolution.
7.6.3 Rotax 912 Engine
The tachometer output from this engine provides 1 pulse per revolution.
7.6.4 TachP/R Table
Tach P/R
Setting*
Pulses per
Revolution
Typical Use
0 1.5 6 -cylinder 4-
strokes
1 1 4-cylinder 4-strokes
2 2 Rotax 2-cylcle non-
cdi
3 3
4 4 Jabiru 6-cylinder
5 5 Jabiru 4-cylinder
6 6 Rotax 2-cycle CDI
7 7
8 8
9 9
10 10
11 0.5
12 12
13 2.5
14 3.5
15 4.5
16 5.5
17 1.25 5-cylinder 4-stroke
18 1.75 7-cylinder 4-stroke
19 2.25 9-cylinder 4-stroke
inc. M14 Radial
Larger than 19
not valid.
Don’t use TachP/R
Settings above 19.
Don’t use TachP/R
Settings above 19.