Potentiometers available on the market consists of several types, namely: carbon potentiometer, potentiometer wire wound and metal potentiometer movie.
1. Potentiometer potentiometer carbon is made of carbon price is quite cheap but very low kepressian this potentiometer resistance is usually the price will be very easy to change due to contact shifting.
2. Potentiometer coil of wire (wire wound) is a potentiometer that uses coils of wire Nikelin a very small cross-sectional size. The accuracy of the potentiometer of this type depending on the size of the wire used and neatness penggulungannya.
3. Metal movie is a potentiometer that uses metal material superimposed to insulating material
Figure 3:42 Various Potentiometer
Potentiometer carbon and metal films are rarely used for industrial control because of rapid wear. Wire wound potentiometer is a potentiometer that uses a fine wire wrapped around the metal rod. Accuracy depends on the size of the wire potentiometers. The wire used is always Nikelin wire. The use of a potentiometer to control the position is quite practical because it requires only one excitation voltage and usually does not require a complicated signal processing. The weakness of the use of potentiometers in particular:
1. Fast wear due to friction
2. Often raised noise, especially when the change occurs saaat position and loose contact
3. Easy attacked by corrosion
4. Be sensitive to impurities
Potentiometer linear potentiometer is very subtle changes in the prisoner with the number of rounds to ten rounds (multi-turn). For the purposes of a linear potentiometer position sensors utilize resistance changes, the necessary protection if the measuring range exceeds the rating, a high linearity results are easy to read, but be careful with friction and backlash caused, limited resolution that is from 0.2 to 0.5%
Figure 3:43 Potentiometer test circuit