Potentiometer switch manufacturer, Omeg 'Make us a component part of your business'


This page provides the electrical and mechanical specification for the P20 product range of Omeg rotary potentiometers.

The electrical specification is split into unique and common attributes to highlight the difference between the ECO, P16 and P20 potentiometer.

Go to P20 Potentiometer Dimensions for the potentiometer bush and spindle dimensions; and
go to P20 Potentiometer Types to select the unswitched model and terminal arrangement to suit your requirements.


The following two options are also available on certain models:-
P20 angle of rotation - without and with a rotary switch
P20 angle of rotation - without and with a rotary switch
In the diagrams above WITHOUT switch is on the LEFT; WITH switch is on the RIGHT;
and the potentiometer terminals are marked A, S and E.


Effective rotation:

Rated Power Dissipation @40°C for P20 potentiometers:

P20 Power dissipating curve
20mm power dissipating curve

Limiting Element Voltage: 500 V DC for P20 potentiometers

P20 Maximum working voltage curve
P20 maximum working voltage curve

Insulating Voltage: 1000 V AC for 20mm potentiometers


Conductive polymer (plastic) track (over twice the life of carbon tracks)

Life Expectancy of >20,000 cycles (tested at 30 times per minute)

Insulation Resistance: >= 4 Gohms

Rated Resistance: E3 Series

Tolerance on Rated Resistance: ± 20%

Resistance Laws (Taper):

Resistance law A - Linear
resistance law A (Linear) curve
Resistance law B - Log (Audio)
resistance law B (Audio/Log) curve
Resistance law C - Antilog (Reverse Audio)
resistance law C (Reverse Audio/Anti Log) curve


As a basis of assessing Linearity Tolerance the independent method is the most practical, permitting as it does, the reference curve to be aligned as near as possible to the actual output curve. This avoids the use of the theoretical starting and finishing points, it is normal for the customer to realign the achieved curve with series trimmers at each end of the device if required.
Linearity Tolerance is 4% over the Nominal Resistance range of 1K0 to 1M0. The Linearity Tolerance is measured on at least 70% of the effective rotation range.

Note. In the case of Terminal and Zero-based linearity, both present constraints which increase the manufacturing difficulty and in consequence have an adverse effect on the product's price and availability.

Potentiometer linearity
potentiometer linearity

Matching Tolerance (For Tandem Stereo Potentiometers)

Tandem Potentiometers have two identical resistor units with the same variation law. The mismatching of the two resistor units, expressed in dB, is measured by the difference between the attenuations introduced by each resistor unit at various points of travel.

Matching tolerance for stereo
matching tolerance for stereo

Operating Temperature: -25°C to +70°C

Temperature derating curve
temperature derating curve

Temperature Coefficient of Resistance: +300 -500 ppm

This information is supplied in good faith but the customer is politely reminded that it is their responsibility to check the suitability of our products for their particular application, production techniques and processes. Please note that all dimensions are for reference purposes only and, as it is the Company's policy to continuously improve our products, we reserve the right to incorporate changes without notice.