[simpits-tech] Simple (?) electronics question - potentiometers

[Roy Coates]

The signal you (and the boards) are interested in is between the wiper and
the ground pin. The voltage on the wiper will vary from the supply voltage
(on your + pin) and the ground pin.

So, wire your supply voltage to the + pin.
wire your - pin to the ground.
Take a wire from the wiper to the input of your plasma board.

Roy.


On 21 February 2012 06:24, <dabigboy at cox.net> wrote:

> Alright, got a little dilemma here, hoping someone can help. I am wiring
> up this Gables nav head for my sim, and the left side of the frequency
> selector (the 108-117) uses a bunch of resistors to determine
> frequency....basically, there are two signal pins. Resistance between those
> pins is varied depending on frequency selection. "Great!" methinks, "I can
> just wire this into a joystick axis and voila!" Old gameport joysticks just
> use two wires, so it should be OK, right? Well, apparently my controller (a
> Beta Innovations Plasma V2) REQUIRES the ground terminal of the pot to be
> connected.
>
> It appears to me that all the ground pot does is provide a "reference"
> voltage, ergo, the max resistance of the pot. The Plasma manual says you
> hook the wiper terminal of the pot to any analog input, then hook the other
> two terminals (+ and -) to any common voltage and common ground terminal,
> respectively. A pot measures its max resistance between the + and -
> terminals, all the time....so, I tried using resistors to equal the max
> resistance of the resistor pack on the Gables unit, and wire that to a
> common negative and common positive terminal on the Plasma. It did not work.
>
> How would I go about wiring this up? I don't really understand why the
> Plasma (and Bodnar board, for that matter) "need" the pots grounded to even
> just have the axis show up and move a little. Or is it that the Plasma
> needs to see the resistance between the wiper and ground be the INVERSE of
> the resistance going to the analog input? If that is the case, I'm not sure
> how I can make this work........
>
> Matt
> _______________________________________________
> Simpits-tech mailing list
> Simpits-tech at simpits.org
> http://www.simpits.org/mailman/listinfo/simpits-tech
> To unsubscribe, please see the instructions at the bottom of the above
> page.  Thanks!
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.simpits.org/pipermail/simpits-tech/attachments/20120221/ddd70e4d/attachment-0001.html