smitchell82 said:
Hi, this is probably the sillyest question ever asked on this forum.. but ive never been able to come across a proper wiring diagram or instructions for a potentiometer. are different models different? where can i get this info?
Potentiometers are available in many styles and with different resitance increments (or "tapers"). For example, mechanical pots are available in slide type and rotary type, with provision for frequent user adjustment (with shafts) or intended for occasional (calibration) adjustment (with screwdriver slots), with linear or audio tapers, and with different resistive elements (carbon composition or nichrome wirewound).
As was already stated, the conventional pot will have three terminals. Two of these terminals are the end points of the resistive element, and will thus have a measured resistance between them equivalent to the labeled value of the pot. The third terminal is connected to the movable contact in the pot, often called the "wiper", the "traveller", or the "slider". It is at this terminal that we will get a varying resistance measured with respect to either end terminal, with the measured resistance being dependent upon the physical distance along the resistive element of the wiper from the relevant end terminal.
A pot with a linear taper has a regular rate of resistance change throughout its travel. In other words, when positioned at the midpoint of the travel range, the resistance at the wiper will be approximately half of the labeled value when measured to either end terminal. Audio taper pots have a logarithmic resistance change wherein the first half of the pot's travel will only offer about one tenth of the total reistance change, with the second half of the travel providing nine tenths of the resitance change. For a more detailed explanation of this,
look here.
Potentiometers can be and often are ganged with addtional pots and/or switches. A common example of this might be a dual ganged pot used as the volume control for a stereo amplifier.
Pots used for panel (user) controls are usually single turn (or less than single turn) devices, but pots are also available in multiple-turn designs. This simply represents the physical action needed to move the wiper from one end of the resistive element to the other. In a single turn device, one full rotation of the control (shaft or screw) will effect this movement. If a device is a ten turn device, it will take ten full rotations of the control to make the full-length travel on the resistive element. Generally speaking, multi-turn devices allow for more precise adjustment than do single turn devices.
Basically, a pot is used when the designer needs a variable resistance for control or calibration. When used as a simple variable resistor, one end terminal and the wiper are used in circuit. When used as a variable voltage divider, all three terminals are used.