I thought this might interest the more thoughtful builders in the group?
>I need to reduce the speed at which my MAC servo adjust the aileron trim
>on my RV9 elevator. 9 volts looks about right and I was wondering if
>there is a simple solid state package that could supply this. Any
>ideas?
>
>Rob.
Sure. Our little half amp dimmers have been used for
this purpose. Instead of adjusting voltage to a light bulb,
you can set the voltage to a more desirable, lower voltage
with the dimmer. You can see the dimmer product at:
http://www.aeroelectric.com/Catalog/lighting/lighting.html#dim5-14
You can download instructions for installing the dimmer
at:
http://www.aeroelectric.com/Catalog/lighting/9013_ins.pdf
This document also illustrates the wiring diagram for
the dimmer which you can use as a guide for fabricating
your own voltage adjustment device . . . the parts needed
to do this are available at Radio Shack.
If you wanted a really compact assembly, the little DIM5-14
assembly can be fitted with a potentiometer right on the
board and eliminate the outboard potentiometer used as
the panel control for dimming.
Bob . . .
> >LM317 is the part, an adjustable voltage regulator
> >
> >why do you want it slower? What you want to do with a electric trim is move
> >it in bumps - press-release not press-and-hold
>
> Many airplanes suffer from poor trim speed selection
> over the full range of the airspeeds. Designers
> have little choice when it comes to off-the-shelf
> actuators to operate trim systems and they seldom
> take the time to optimize the mechanical gain between
> the selected trim actuator and the trim tab . . .
>
> It's not uncommon for builders to find that the
> trim system is too fast in cruising speed to accurately
> trim the airplane. I designed the first multi-speed
> trim system for the Lears about 20 years ago that
> allowed full speed ops in the approach/departure phases
> but slowed it down by about a factor of 4 during
> cruise. Pilots loved it.
>
>
> Bob . . .
>
> ( An inventor is simply a person who doesn't take his education )
> ( too seriously. We often say that the biggest job we have is )
> ( to teach a newly hired employee how to fail intelligently. )
> ( We have to train him to experiment over and over and to keep )
> ( on trying and failing until he learns what will work. )
> ( Charles Kettering )
> http://www.aeroelectric.com
>
>
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