all the E-MAG innovations, the self-powering capability of the "P" Model is
the most significant. It solves the largest single issue faced by
all electronic ignitions - their need for an uninterruptible power
supply. Power back-up strategies that a) compromise ignition effectiveness, b) solve only half
the problem, or c) require additional maintenance are less than ideal.
Next-Generation ignitions need a better solution.
what does a next-generation electrical back-up need to do?
- Above all, it has to be reliable. When it's needed, it has to
work - period.
- It should operate for as long as
needed. Whether it's the last 10 minutes of a Sunday pleasure
flight, or you're crossing the Atlantic.
- It should be maintenance-free. Benign
neglect should not prevent it from working.
- On the rare occasion it's needed, it should
automatically engage without operator intervention.
- A simple and convenient pre-flight check should confirm it's working
Our P model ignition has an internal
three phase brushless alternator that produce enough power to sustain the
ignition when the engine is turning 800 rpm, or more. If the
aircraft buss voltage goes off-line, the ignition has an internal alternator. With
this arrangement, dual electronic ignitions can be run "clean".
batteries and no back-up magnetos.
The P Model
(zero) mechanical contact/wear parts to the system.
Adds only a few ounces of weight.
Requires no additional hardware
Will operate as long as the
engine is turning.
means improving on products that came before.
Prior to the P model,
electronic ignitions addressed the risk of electrical
power loss by:
- Installing back-up batteries, together with switching circuits, to A)
engage the back-up battery when needed, and possibly B) keep the back-up
battery charged. This solution:
- Adds wiring, switches, and batteries not part of the ignition
kit typically provided by the manufacturer.
a finite interval of back-up power.
marginal confidence insofar as batteries are not known for unquestioned
Converting only one ignition to
electronic, and maintain one magneto as a power failure back-up. This solution:
advantages of variable ignition timing and dual
spark. Most of the time, mag timing (fixed) will fire
before or after an electronic ignition using variable timing.
Aircraft engines are
designed for simultaneous firing from two plugs. Firing on one
plug is not optimal.
Compromises the maintenance advantage of electronic
ignitions. The owner has the same inspection, maintenance,
and cost components as before, albeit for one vs. two magnetos.
- Maintaining dual magnetos and piggy-back an electronic
ignition on each. In the event of electrical power loss, both ignitions
can revert to magneto operation. This solution:
- Doesn't reduce the maintenance associated with
magnetos. It adds what ever (minimal) attention is required for
the electronic side.
- Doesn't eliminate underlying reliability issues
associated with magnetos.
- Doesn't streamline the cost and complexity of the
ignition package, as a whole. It makes it more complicated
and much more expensive to produce.
- Requires spark plug gaps be set so magnetos are able to
fire. A key advantage of electronic ignitions is the ability to increase
spark plug gap to nearly double that of a magneto. You can't
do that if your power back-up plan has the plug firing from a magneto.