Thumbwheel Potentiometer

6 August 2018 - 0 Comments

5 Terminal Thumbwheel Potentiometer

Thumbwheel Potentiometer Pinout

Pin Configuration

Pin No.	Pin Name	Description
1	GND	Common pin connected to ground
2	R1I/P	Input to first variable resistance unit, channel 1
3	R1O/P	Output of first variable resistance unit, channel 1
4	R2O/P	Input to second variable resistance unit, channel 2
5	R2O/P	Output of second variable resistance unit, channel 2

Features and Specifications

RK10J is 10mm size
RK14J is 14mm size
Total resistance tolerance is ±30％
Maximum operating voltage is 50V AC, 20V DC （Single-unit only）
Total rotational angle 270°±10° (RK10J) and 270°±5° ( for RK14J)
Rotational torque 0.5 to 10mN・m (for RK10J) and 1 to 10mN・m (for RK10J)
Operating life 10,000 cycles
Nob color is black
Single unit and double unit resistor elements available

Alternatives

Resistors, Trimmers, TrimPot

Brief Description

Potentiometers also known as POT are nothing but variable resistors. They can provide a variable resistance by simply varying the knob on top of its head. It can be classified based on two main parameters. One is their Resistance (R-ohms) itself and the other is its Power (P-Watts) rating.

Potentiometer comes in various structure and designs. Some have rotatory shaft, some come in compact size known as preset w resistor or trimmer pot which have the arrangement to adjust the resistance at a desired value. Then there are potentiometers called sliders whose resistance varies with the linear moving slide control.

Thumbwheel potentiometer has a rotatory wheel which moves in circular motion and the potentiometer resistance various simultaneously.

Three pin and five pin thumbwheel potentiometer are the two types of the thumbwheel potentiometers.

In general, thumbwheel potentiometer with five terminals has dual variable resistance element, therefore have two moving contacts for two different input and output control. It is used mostly to control dual channels like in headphone's audio control.

Thumbwheel potentiometer with three terminals has single variable resistance element inside, hence there is single rotatory shaft inside. It is used mostly to control volume of an audio player, CD cassette player for some single channel control of volume.

3 Terminal Thumbwheel Potentiometer

How to select a thumbwheel potentiometer?

Thumbwheel potentiometer have different model, wheel nob dimensions, unit type (no. of resistance element) and the total resistance value.

Below is an example-

How to Select a Thumbwheel Potentiometer

Model type gives us the different size of thumbwheel potentiometer.

Shaft type specifies the wheel size or the outer dimensions of the pot

Resistance taper helps us to select the pot for specific application like B-for tone and general purpose and V- volume control

Total Resistance is equal to 203=20^3= 20 kΩ

Depending on the application appropriate potentiometer can be selected considering the above parameters. Thumbwheel potentiometer is very easy to handle as its variable nob is very smooth in control.