>The trim enable switch, as shown in Europa's diagram, enables the trim
>readout as well as movement. Since the trim is connected directly to the
>battery, leaving the trim enabled will cause a continuous drain on the
>battery due to activation of the readout. Why is the trim not disabled by
>the master switch? Is this to leave the trim enabled when the master is
>turned off prior to an emergency landing?
The circuit diagram in the Europa manual calls for the trim switch to have
its own 'master' switch. This means that you can switch off all electrics
whilst still retaining trim in an emergency.
>I plan to mount the trim switch on the stick, with the enable switch next to
>the trim indicator. I am unclear on how the trim enable switch should be
>used to prevent trim runaway,
We have got both stick and panel mounted trim switches on 'XDY. We have got
the above mentioned trim 'Master' switch/breaker which then goes through a 2
pole 2 way switch as per the MAC instructions to divert control to either
the panel or the stick. Overall this means that we have 2 ways of
controlling runaway if it is the usual switch induced. We can either divert
control to the panel or stick, or we can switch the whole system of with the
trim master.
>another idea occurred: connect a
>zener in one side so that in one of the positions the voltage and thus the
>trim speed is reduced. Seems like a reasonable thing to want based on
>comments offered on the sensitivity of the Europa's trim.
In practice we have found no problems with the speed of the trim system, as
supplied, although I could just about see that if you were really going to
nit pick right down to the last item, you could possibly ask for a slightly
slower speed when trying to make very small adjustments. But really, we have
not had any problems at all.
Dave Watts ('XDY)
|