Variable Resistors
±2%
Tightest Tolerance
Tightest Tolerance
0.1W – 3000W
Power Range
Power Range
22Ω – 4.7MΩ
Resistance Range
Resistance Range
4 Types
Technologies
Technologies
Technologies:
Potentiometer
l
Rheostat
l
Cermet
l
Precision
What Is a Variable Resistor?
A practical overview for engineers and procurement teams evaluating resistive solutions.
A variable resistor is a passive component that allows resistance to be adjusted manually or mechanically — as opposed to a fixed resistor whose value is set at manufacture. RARA's variable resistor range covers two fundamental types: potentiometers, which are three-terminal voltage dividers used for signal-level control and adjustment, and rheostats, which are two-terminal high-power variable resistors used for current and power control in industrial systems.
At the low-power end, carbon potentiometers (PR-16, PR-18, PR-24, SP) provide economical, reliable adjustment for audio, lighting, and general-purpose control circuits. Cermet potentiometers (CN-15, PC-199, CW-18) offer improved stability and longer service life than carbon types — the PC-199 and CW-18 are hermetically sealed for use in demanding environments. Precision wire wound potentiometers (DM, DOW, DG) deliver the accuracy needed for calibration, instrumentation, and closed-loop control applications.
At the high-power end, the BC1 wire wound rheostat series handles 25W to 3000W of continuous power — used for motor speed control, current limiting, and power regulation in heavy industrial equipment where large, stepless resistance adjustment is required.
Construction Technologies
-Carbon potentiometers (PR-16, PR-18, PR-24, SP)
-Cermet potentiometers (CN-15, CW-18)
-Hermetic cermet potentiometer (PC-199)
-Precision wire wound potentiometers (DM, DOW, DG)
-Wire wound power rheostat (BC1 — up to 3000W)
-Carbon potentiometers (PR-16, PR-18, PR-24, SP)
-Cermet potentiometers (CN-15, CW-18)
-Hermetic cermet potentiometer (PC-199)
-Precision wire wound potentiometers (DM, DOW, DG)
-Wire wound power rheostat (BC1 — up to 3000W)
Key Advantages
-Full range from signal-level to 3000W power control
-Hermetically sealed cermet models for harsh environments
-Precision wire wound types for calibration use
-Wide resistance range: 22Ω to 4.7MΩ
-ISO 9001 and IATF 16949 certified manufacturer
-Full range from signal-level to 3000W power control
-Hermetically sealed cermet models for harsh environments
-Precision wire wound types for calibration use
-Wide resistance range: 22Ω to 4.7MΩ
-ISO 9001 and IATF 16949 certified manufacturer
RARA variable resistors come in potentiometer and rheostat designs — from compact 15mm cermet trimmers at 1W to massive 3000W industrial wire wound rheostats for heavy-duty power control.
Applications
Where RARA variable resistors are deployed in the field.
General Purpose Signal Control
Carbon potentiometers (PR-16, PR-18, PR-24) are the standard choice for volume controls, brightness adjustment, speed setting knobs, and general-purpose panel control in consumer electronics, industrial HMIs, and test equipment — offering wide resistance range up to 4.7MΩ in a compact rotary format.
Carbon potentiometers (PR-16, PR-18, PR-24) are the standard choice for volume controls, brightness adjustment, speed setting knobs, and general-purpose panel control in consumer electronics, industrial HMIs, and test equipment — offering wide resistance range up to 4.7MΩ in a compact rotary format.
Calibration & Instrumentation
Precision wire wound potentiometers (DM, DOW, DG) with tolerances to ±2% and stable wire wound elements are used for calibration adjustments, setpoint controls, and feedback trimming in measurement instruments, process controllers, and analog signal conditioning circuits where repeatability over time is essential.
Precision wire wound potentiometers (DM, DOW, DG) with tolerances to ±2% and stable wire wound elements are used for calibration adjustments, setpoint controls, and feedback trimming in measurement instruments, process controllers, and analog signal conditioning circuits where repeatability over time is essential.
Harsh & Sealed Environments
The PC-199 and CW-18 hermetically sealed cermet potentiometers resist moisture, dust, and contamination — making them suitable for outdoor control panels, marine equipment, military systems, and industrial machinery where an unsealed potentiometer would fail due to environmental ingress.
The PC-199 and CW-18 hermetically sealed cermet potentiometers resist moisture, dust, and contamination — making them suitable for outdoor control panels, marine equipment, military systems, and industrial machinery where an unsealed potentiometer would fail due to environmental ingress.
Industrial Motor Speed Control
The BC1 wire wound rheostat (25W–3000W, 1Ω–10kΩ) is used for direct current control in DC motor drives, resistance welding machines, electrolysis equipment, and industrial heating elements — where smooth, stepless power adjustment over a large range is required continuously.
The BC1 wire wound rheostat (25W–3000W, 1Ω–10kΩ) is used for direct current control in DC motor drives, resistance welding machines, electrolysis equipment, and industrial heating elements — where smooth, stepless power adjustment over a large range is required continuously.
Lighting & Dimming Control
Carbon and cermet potentiometers serve as dimmer controls in theatrical lighting, industrial LED drivers, and laboratory illumination systems. The CN-15 trimming cermet type is particularly suited to PCB-level brightness adjustment where the control is set once and not frequently changed.
Carbon and cermet potentiometers serve as dimmer controls in theatrical lighting, industrial LED drivers, and laboratory illumination systems. The CN-15 trimming cermet type is particularly suited to PCB-level brightness adjustment where the control is set once and not frequently changed.
Laboratory & Test Equipment
Precision wire wound potentiometers (DOW at 4W, ±2–5%) provide the power handling and accuracy needed for variable load simulation, resistance substitution boxes, and adjustable reference circuits in laboratory power supplies, impedance bridges, and electronic test fixtures.
Precision wire wound potentiometers (DOW at 4W, ±2–5%) provide the power handling and accuracy needed for variable load simulation, resistance substitution boxes, and adjustable reference circuits in laboratory power supplies, impedance bridges, and electronic test fixtures.
Product Series
Select models from our variable lineup. Download individual datasheets for full specifications, dimensions, and ordering codes.
Model: CN-15
Resistor type: Variable
Description: 15mm, trimming cermet potentiometer
Power Rating: 1W
Resistance (Ω): 100~4.7M
Tolerance (%): ±20, ±30
TCR (ppm/C): 300
Model: PR-16
Resistor type: Variable
Description: 16mm, carbon single turn potentiometer
Power Rating: 0.1W
Resistance (Ω): 100~2.2M
Tolerance (%): ±5, ±10, ±20, ±30
Model: PR-18
Resistor type: Variable
Description: 18.5mm, carbon single turn potentiometer
Power Rating: 0.2W
Resistance (Ω): 120~4.7M
Tolerance (%): ±5, ±10, ±20, ±30
Model: PR-24
Resistor type: Variable
Description: 24mm, carbon single turn potentiometer
Power Rating: 0.5W
Resistance (Ω): 100~2.2M
Tolerance (%): ±5, ±10, ±20, ±30
Model: PC-199
Resistor type: Variable
Description: 19mm, hermetic cermet potentiometer
Power Rating: 1W
Resistance (Ω): 100~4.7M
Tolerance (%): ±10, ±20, ±30
Model: SP
Resistor type: Variable
Description: 29mm, carbon single turn potentiometer
Power Rating: 2W
Resistance (Ω): 470~4.7M
Tolerance (%): ±10
Model: CW-18
Resistor type: Variable
Description: 18.5mm, hermetic cermet potentiometer
Power Rating: 1W
Resistance (Ω): 100~4.7M
Tolerance (%): 20, ±30
TCR (ppm/C): 300
Model: DM
Resistor type: Variable
Description: Precision wire wound potentiometer
Power Rating: 0.75W
Resistance (Ω): 22~47k
Tolerance (%): ±2.5, ±5, ±10
Model: DOW
Resistor type: Variable
Description: Precision wire wound potentiometer
Power Rating: 4W
Resistance (Ω): 22~47k
Tolerance (%): ±2, ±5
Model: DG
Resistor type: Variable
Description: Precision wire wound potentiometer
Power Rating: 2W
Resistance (Ω): 22~3.3k
Tolerance (%): ±5, ±10
Model: BC1
Resistor type: Variable
Description: Wire wound precision rheostat
Power Rating: 25W~3000W
Resistance (Ω): 1~10k
Tolerance (%): ±5, ±10
TCR (ppm/C): 400 max.
Why Choose RARA Variable Resistors
What sets RARA apart for engineers and procurement managers in industrial and automotive markets.
01
Full Spectrum Coverage
From 0.1W carbon signal potentiometers to 3000W industrial wire wound rheostats — RARA covers the complete variable resistor spectrum from a single ISO 9001 certified supplier.
Full Spectrum Coverage
From 0.1W carbon signal potentiometers to 3000W industrial wire wound rheostats — RARA covers the complete variable resistor spectrum from a single ISO 9001 certified supplier.
02
Hermetic Sealed Options
PC-199 and CW-18 hermetically sealed cermet models resist moisture, dust, and contamination — extending service life in outdoor, marine, and industrial environments where standard potentiometers degrade rapidly.
Hermetic Sealed Options
PC-199 and CW-18 hermetically sealed cermet models resist moisture, dust, and contamination — extending service life in outdoor, marine, and industrial environments where standard potentiometers degrade rapidly.
03
Precision Wire Wound
DM, DOW, and DG precision wire wound potentiometers deliver the accuracy and repeatability needed for calibration, instrumentation, and closed-loop feedback applications.
Precision Wire Wound
DM, DOW, and DG precision wire wound potentiometers deliver the accuracy and repeatability needed for calibration, instrumentation, and closed-loop feedback applications.
04
Global Track Record
Trusted by Siemens, Rockwell, Schneider Electric, and Hanwha — deployed in industrial control and power regulation systems across six continents.
Global Track Record
Trusted by Siemens, Rockwell, Schneider Electric, and Hanwha — deployed in industrial control and power regulation systems across six continents.
Products & Downloads
Information & Schedule
100B-11L, 138 Cheongneung-
daero 410beon-gil,
Namdong-gu, Incheon
TEL : +82-70-4355-4327
FAX : +82-32-817-4328
Email: osm1@raraohm.com
daero 410beon-gil,
Namdong-gu, Incheon
TEL : +82-70-4355-4327
FAX : +82-32-817-4328
Email: osm1@raraohm.com
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