I have used two of the three terminals to vary the resistance for controling the gain or amplification for audio. I am newbie and haven't used the three terminals all at the same time. I guess it might be used to split current or perhaps some usage for varying the voltage drop? Is there any circuit for hobbyist to build to use all three terminals for some sort of cool device?
The "right" way to use a potentiometer for a volume control is to connect the output of your preamp stage to the 'top' of the pot, connect the 'bottom' to ground, and take the audio off of the tap.
Similarly, if you want to use a potentiometer for a position feedback, you would power the top and bottom terminals with either +V and ground, or +V and -V, and take the position reading off of the tap. Using the
+V/-V method means that the tap voltage is proportional to the (signed) position around center, where the +V/0V method means you have to interpret the position as having one sign, or you have to add in an offset yourself.Start paying attention to circuit design projects on web pages or in magazines, and you'll see this.
-- Tim Wescott Wescott Design Services http://www.wescottdesign.com Do you need to implement control loops in software? "Applied Control Theory for Embedded Systems" gives you just what it says. See details at http://www.wescottdesign.com/actfes/actfes.html
This describes the simplest example of a "pad". It is VERY dependent on the impedances of *other* elements in the circuit. (With a "pot", you want that other stuff to be "swamped out".)
...and if you're only using 2 terminals, you're using the wrong term:
Here is the fundamental concept of a potentiometer (without the fancy name).
You use all 3 terminals for a potentiometer, most popularly in your instance as a volume control.
Using only 2 terminals as a volume control will result in a limited range that will never be fully off.
Graham
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Think of it as voltage divider. In some instances that can be an oversimplification but helps understanding.
Across the two ends connect the full input voltage. Let's say (for sake of argument that is ten volts).
Between one end and the 'slider' the movable connection. You will get a voltage which depends on the location/position of the movable connection.
As an example you would expect that if half-way one would get say 5 volts!
What you actually get depends how the resistance varies across the approx. 270 degree rotation. (of a circular 'Pot'). The variation is sometimes referred to as 'taper'.
An older name for them is potentiometer; meaning you can adjust and measure the output voltage
The potentiometer has to fit into (MATCH) the type of circuit in which it is used. One could not for example connect a half megohm 'potentiometer' into a 4 ohm speaker circuit and expect to do anything but give full volume to a speaker, at maximum setting!!!! And probably not much elsewhere the moment the 'pot' is turned away from maximum.
Any help?
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