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Introduction • On Precision Pots • General Product Definitions • Construction Details • Multiturn Precision Pots • Resistive Elements • Terminals • Shaft-Rotor Assembly • Mechanical Rotation • Mounting Methods • 3540 Family • 3590 Family • Knobpot 3600 Family • Single-Turn Precision Pots • 6537/6637 Family • 6539/6639 Family • 3680 Pushbutton Family • Special Precision Pots • Shafts • Mounting Styles • Bearings • Torque • Linearity • Wiper Load • Low Current Applications • High Rotational Speed • Angles • Additional Taps • Sealed Units • Multicup Assemblies • Envelopes •
Environmental • Competition •
Useful Terms
High Rotational Speed
Bourns potentiometers are designed for moderate speed applications. The limiting factor is determined by the element construction. In specifying a potentiometer for applications involving high rotational speed, it is important to keep in mind the trade-off factors with respect to performance, life expectancy and electrical noise.
Standard Models
The viscosity of long-life lubricants may cause the wiper to lift up off the element at high rotational speeds of 60 RPM or higher. Should this condition occur, the end user would see an open wiper condition or discontinuity in electrical output. This effect varies depending on the type of element.
Conductive Plastic Elements
Conductive plastic elements without lubricants are capable of performing at speeds of 500 RPM and above without the effects of wiper discontinuity. However, the rotational life will be reduced and noise will increase.
A compromise solution is a light wipe of lubricant on the element surface. Residual lubricant in the pores of the film surface allows high rotational speed without wiper lift and only marginal reduction of rotational life. Electrical noise can be controlled by the application of low pass filters in the customer's circuit design.
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