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Trimming Potentiometers carry specifications for potentiometer category and actuator configuration. Industrial-grade potentiometers are protected by an enclosure, typically one that is rated by the National Electrical Manufacturers Association (NEMA). Typically, industrial-grade products are gear-driven and have connector outputs. These Trimming Potentiometers resist the ingress of dirt and dust, and last longer than unenclosed potentiometers. Discrete-board components, another potentiometer category, are also commonly available. In terms of actuator configuration, choices include single-turn, multi-turn, and slide. With single-turn devices, the shaft rotation is limited to less than or equal to 360 degrees. By contrast, multi-turn Trimming Potentiometers can be rotated multiple times, with as many as 15 or 20 turns from stop to stop. Slide-actuated products require the user to move a handle instead of rotating a knob.

A membrane potentiometer uses a conductive membrane that is deformed by a sliding element to contact a resistor voltage divider. Linearity can range from 0.5% to 5% depending on the material, design and manufacturing process. The repeat accuracy is typically between 0.1mm and 1.0mm with a theoretically infinite resolution. The service life of these types of potentiometers is typically 1 million to 20 million cycles depending on the materials used during manufacturing and the actuation method; contact and contactless (magnetic) methods are available. Many different material variations are available such as PET(foil), FR4, and Kapton. Membrane potentiometer manuafacturers offer linear, rotary, and application-specific variations. The linear versions can range from 9mm to 1000mm in length and the rotary versions range from 0° to 360°(multi-turn), with each having a height of 0.5mm. Membrane potentiometers can be used for position sensing.http://www.kingtronics.com/trimming-potentiometers/

One of the most common uses for modern low-power potentiometers is as audio control devices. Both linear potentiometers and rotary potentiometers are regularly used to adjust loudness, frequency attenuation and other characteristics of audio signals. The 'log pot' is used as the volume control in audio amplifiers, where it is also called an "audio taper pot", because the amplitude response of the human ear is also logarithmic. It ensures that, on a volume control marked 0 to 10, for example, a setting of 5 sounds half as loud as a setting of 10. There is also an anti-log pot or reverse audio taper which is simply the reverse of a logarithmic potentiometer. It is almost always used in a ganged configuration with a logarithmic potentiometer, for instance, in an audio balance control.

Transducers

Potentiometers are also very widely used as a part of displacement transducers because of the simplicity of construction and because they can give a large output signal.

Computation

In analog computers, high precision potentiometers are used to scale intermediate results by desired constant factors, or to set initial conditions for a calculation. A motor-driven potentiometer may be used as a function generator, using a non-linear resistance card to supply approximations to trigonometric functions. For example, the shaft rotation might represent an angle, and the voltage division ratio can be made proportional to the cosine of the angle.

Variable resistors used as potentiometers have all three terminals connected.

This arrangement is normally used to vary voltage, for example to set the switching point of a circuit with a sensor, or control the volume (loudness) in an amplifier circuit. If the terminals at the ends of the track are connected across the power supply then the wiper terminal will provide a voltage which can be varied from zero up to the maximum of the supply.

Kingtronics is a manufacturer of Trimming Potentiometer. Trimming potentiometers are Kingtronics' first products. On Kingtronics' trimming potentiometers body, we mark "King" due to insufficient space. “Kingtronics” and "Kt" are our brand too. So, Kingtronics trimmers, Kingtronics potentiometers, King trimmers, and King potentiometers all mean potentiometers which produced by Kingtronics International Company.Our products are well crossed to Bourns Brand parts. We offer Kingtronics potentiometers (with Kt Mark trimming potentiometer) include following part number: RKT-3006, RKT-3266, RKT-3296, RKT-3299, RKT-3323, RKT-3329, RKT-3362, RKT-3386, RKT-3318, RKT-3306, RKT-3309, RKT-065, RKT-105H, RKT-C3305, RKT-3361, RKT-3540S, RKT-3590. Our trimming potentiometers are RoHS compliant.

Now Kingtronics offer Bourns equivalence. If you want more details , please visit website:www.kingtronics.com  for full specification.

If you have any inquiry about Trimming Potentiometer , pls contact info@kingtronics.com.

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The reliability of a potentiometer depends on its ability to continue performing its intended function. Since the primary function is to provide a continuous and proportional voltage output, the primary reliability considerations are continuity and proportional voltage output. A failure in continuity is always catastrophic, as the device is no longer acting as a potentiometer.

The primary constituents of continuity are:

Wiper contact to conductive surface

Continuous conductive surface

Wiper (output) and excitation terminal continuity

Dielectric Voltage - The dielectric (insulation of Potentiometer "guts" to the body) rating is especially important if the Potentiometer is connected to mains operated, non-isolated equipment. Wall mounted lamp dimmers and such are typical examples. This is not commonly specified, but for safety, should be at least 2.5kV. A common way to achieve this is to use a plastic shaft, with the body of the Potentiometer insulated from the chassis, and inaccessible by the user - even if the knob falls off or is removed! This point cannot be stressed highly enough.

Most standard Potentiometer will safely withstand (maybe) 100V or so between the resistance element and terminals, and the body and shaft. Miniature types will usually be less than this. Never, ever, use a standard Potentiometer with a metal shaft to control direct mains operated equipment. Even if the Potentiometer case is earthed, the voltage rating between the internal element(s) and terminals to the case is often unspecified, and is almost always completely unsuited to mains voltages.

If RL is large compared to the other resistances (like the input to an operational amplifier), the output voltage can be approximated by the simpler equation:

As an example, assume

, , , and 

Since the load resistance is large compared to the other resistances, the output voltage VL will be approximately:

Due to the load resistance, however, it will actually be slightly lower: ≈ 6.623 V.

One of the advantages of the potential divider compared to a variable resistor in series with the source is that, while variable resistors have a maximum resistance where some current will always flow, dividers are able to vary the output voltage from maximum (VS) to ground (zero volts) as the wiper moves from one end of the potentiometer to the other. There is, however, always a small amount of contact resistance.

In addition, the load resistance is often not known and therefore simply placing a variable resistor in series with the load could have a negligible effect or an excessive effect, depending on the load.

A trimmer or preset[1] is a miniature adjustable electrical component. It is meant to be set correctly when installed in some device, and never seen or adjusted by the device's user. Trimmers can be variable resistors (potentiometers), variable capacitors, trimmable inductors. They are common in precision circuitry like A/V components, and may need to be adjusted when the equipment is serviced. Unlike many other variable controls, trimmers are mounted directly on circuit boards, turned with a small screwdriver and rated for many fewer adjustments over their lifetime. Trimmers like trimmable inductors and trimmable capacitors are usually found in superhet radio and television receivers, in the Intermediate frequency, oscillator and RF circuits. They are adjusted into the right position during the alignment procedure of the receiver.

Trimmers come in a variety of sizes and levels of precision; for example, multi-turn trim potentiometers exist, in which it takes several turns of the adjustment screw to reach the end value, allowing for very high degrees of accuracy.

Since 1990 , Kingtronics International company founded its first factory in mainland of China . For 20 years development and experience in manufacturing timpots , Kingtronics brand is well known by more and more pepole .

Now Kingtronics offer Bourns equivalence: 3006, 3266, 3296,  3323, 3329, 3362, 3386,3309, 3540, 3590 . If you want more details ,please visit website: www.kingtronics.com for full specification.