Wednesday, December 29, 2010
【 Weak current College 】 potentiometer parameter 】
Potentiometer parameters, such as nominal resistance, rated power, resistance variation, dynamic noise, zero Tuen resistance and contact resistance, the humidity coefficient, insulation resistance, wear-resistant life, maximum working voltage, precision, scale, etc. The following are introduced frequently used several parameters:
(1) potentiometer nominal resistance callout in the potentiometer on resistance is called the nominal resistance. Its value is equal to the potentiometer two fixed bow out of the Division of resistance, resistance series potentiometer with E12, E6. And wire-wound and nonlinear round two.
Potentiometer allows deviation for wire wound potentiometer with ±10%, ±5%, ± 2%, ± 1%. For nonlinear around 20% potentiometer is ±, ±10%, ±5%.
(2) potentiometer rating refers to certain provisions of atmospheric pressure and humidity, potentiometer can be continuously during normal working, consumes the maximum allowed power.
Potentiometer power rating is based on the nominal range of annotated. And wire wound and nonlinear around different. For example, wire wound potentiometer with 0.25W, O.5W, 1W, 2W, 3W 1.6W,, 5W, 1OW, 16W, 25W, 40W, 63W, 1OOW. While there is nonlinear round potentiometer 0.025W, 0.05W, 0.1W, 0.25W, 0.5W, 1W, 2W, 3W.
(3) potentiometer sliding noise in the applied voltage, the dynamic contact potentiometer on slip resistance, the resulting electrical noise called potentiometer dynamic noise.
Potentiometer-noise is to select one of the main parameters of the potentiometer, because it effects on electronic equipment, larger, sometimes will enable electronic devices work, such as radios, televisions, etc.
(4) potentiometers for rated operating voltage is also called maximum working voltage, refers to the potentiometer in the conditions, long-term reliable allows the maximum voltage. In the use of voltage is usually less than the rated voltage, in order to ensure the potentiometer ofnormal use.
(5) change of potentiometer resistance refers to the potentiometer of resistance, with the axis of rotation and changes in the relationship. Variation in three different forms, i.e. linear type, exponential, logarithmic, respectively by the letters x, z, d.
Linear potentiometer resistance is doing with the hinge of the rotation and of uniform change and proportional to the angle of rotation. That means resistance with the rotation angle of the grows. This potentiometer divider suited for bias adjustment,.
Logarithmic potentiometer of resistance, with the hinge of the relationship between the rotating do logarithmic. That means the resistance of the changes begin larger, then change gradually slows down, the potentiometer is suitable for making the pitch control and black and white TV hungry black and white contrast adjustments.
Index of potentiometer of resistance, with the axis of rotation do index rule changes. That means the resistance of the changes started to slow, the increase in the future with the corner, the resistance changes gradually speed up. This potentiometer for for volume control.