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EPICfan

Good quality potentiometers (sliders, rotary) recommendation?

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I recently rewired my flight controls from parallel port to USB. For this, I cannibalized a USB-joystick and used 10 audio kOhm linear faders as pots (parallel was using 100 kOhm).

 

Unfortunately, I am getting quite a lot of jitter from those pots, and I am thinking of changing all over again and going for a Leo Bodnar product such as this:

 

http://www.leobodnar.com/shop/index.php?main_page=product_info&cPath=67&products_id=180

 

However, Leo advises against using audio pots and makes some recommendations for suppliers. Unfortunately, these suppliers only offer rotary pots.

 

I would be glad for any advice about where to buy linear sliding pots (faders) with good quality to eliminate jitter. If you can recommend a source for rotary pots, I will gladly take your advice, too.

 

Best regards,

Holger

 

 

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Mouser, Allied Electronics, and Newark Electronics all come to mind.

 

If you're using Leo Bodnar's boards, they work very well with Hall Effect sensors...I had a lot of fun converting my six-lever PFC throttle quadrant from linear pots that were always wearing out to HE sensors.

 

Cheers

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Bob, would you believe that I have always dreamt of something like Hall Effekt Sensors, but did not know they existed (well, actually in my dreams I was thinking up something with infrared)?

 

Can I acquire these sensors at the places you mention in the first line of your reply?

 

And do I have to look for certain specifications like linear, certain amount of kOhm?

 

Kind regards,

Holger

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I have read up a bit on the topic and found this very helpful:

 

http://www.jpfiles.com/hardware/uni_stick.pdf

 

So if I understand the concept correctly, the sensor "reads" according to the variation in angle. Since I am planning to replace sliding pots - is there also a similar device which would read variation in distance?

 

Best regards,

Holger

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I have read up a bit on the topic and found this very helpful:

 

http://www.jpfiles.com/hardware/uni_stick.pdf

 

So if I understand the concept correctly, the sensor "reads" according to the variation in angle. Since I am planning to replace sliding pots - is there also a similar device which would read variation in distance?

 

Best regards,

Holger

I use Allegro A1321EUA HE sensors (less than $2 each) in various configurations to measure either angle or linear travel. The IC "reads" the strength of a magnetic field across its sensor, nothing more. So some understanding of how measured field strength changes as a function of distance and angle is necessary...it's not necessarily as simple as just buying a sensor and mounting it. In the case of the aileron and elevator axes, I was able to use a commercial off-the-shelf rotary HE sensor to replace the pots in the PFC yoke.

 

On my modified PFC rudder pedals, I use an HE sensor mounted above a 1/2" neodymium cube magnet to measure angular rotation, and I also use a couple of the same sensors mounted off the ends of a 1/4" x 1/8" neodymium disc magnet to measure linear brake pedal movement. In the case of the brake pedal sensors, I wrote a software driver that transforms the nonlinear response of measured magnetic field as a function of distance between the magnet and sensor to a linear measure of movement, using FSUIPC to both read the raw value from the BU0836X joystick axis and then to write the converted value out to the brake axis in FSX.

 

In my throttle quadrant, I use HE sensors that are moved linearly by the lever between two opposing 1/2" magnets...the response is semi-linear, but I also run a driver doing a real-time transform to make the axis input to the sim nearly perfectly linear across the range of travel.

 

It was a fun project...and a fair bit of work. But now I have a set of flight controls, including a floor-mount yoke, a six-lever throttle quad, and rudder pedals with proportional brakes, using HE sensors on every axis and with response as smooth as a baby's behind. And with no pots wearing out, I don't expect to have to change these out for a very long time. I now keep a couple spare BU0836X joystick boards and a box of HE sensors around just to play with...I'm sure I will come up with some new ways to use these in the future.

 

Cheers

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All right, I ordered the parts, and I am ready to experiment. As far as the wiring is concerned, woul 0.5 mm (0.02") stranded wire be ok? Or would this be too thick?

 

Best,

Holger

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I have been using 22 ga (0.025") hookup wire in my Hall setups and it works fine.

 

Regards

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