When a schematic shows a pot with an input, an arrow from the middle post returning to the pot itself, and a ground, what exactly does one with the middle lug? Is the schematic indicating that this post should be left open (untouched), that it should be connected to the housing of the pot (which would be ground?), or what? I just don't feel like I'm understanding that particular symbol . . . I'm still pretty new at this, obviously.
Thanks
it is being used as a varible inline resistor. so you need to connect two of the lugs together. or just use one outside lug and one insdie lug.
that schematic symbol is one I've always thought was a little bit deceptive - when looking at it, it seems like the outside lug is the important one to connect, when in fact the inside lug is the important one. As a matter of habit, most people connect the outside and inside lug together, because of potential problems with aging pots. As the pot wears down, there can be situations where the wiper (attached to the middle lug) will lost connection to the resistive material (which has each end attached to one of the outside lugs). Connecting the wiper to the unused outer lug assures that even if there is a momentary loss of contact between the wiper and the resistive strip, there will still be *some* electrical connection across the pot (the connection will be the equal in resistance to the total value of the pot, since the signal will travel the entire length of the strip getting from one outer lug to the other). This can avoid some pops and crackles when operating a worn down pot.