Wirewound Power Variable Resistors, Rheostats, Potentiometer


Providing design engineers with economical Power Rheostats (Variable Resistors, Potentiometer)
With high quality performance.

Tokenchina FVR rheostats are designed and manufactured to operate smoothly and reliable over long periods of use. These rugged variable resistors can handle 25W, 50W and 100W Watts of power, 5 Ω to 5K Ω resistance range.

The rheostat FVR are wound with resistive copper or chromium-alloy wire on a ceramic base with metal and are coated with protective vitreous enamel or silicone.

Power Variable Wirewound Rheostat Resistors - FVR Series


  • Linear windings on stock models, Windings secured to prevent shifting.
  • Potentiometer and rheostat applications, Tapered windings available on a special order basis.


  • Load simulations, Industrial machinery RPM adjustment.
  • Speed control of DC motors and Wound-Rotor motors for field excitation.
  • Voltage control of generators and exciters; Adjustment of voltage and current in control circuits.

Resistance Tolerance:

  • K(±10%)

The Rheostat FVR series is lead-free and RoHS compliant. Please contact us for details with your specific needs.

Variable FVR - 25W, 50W, 100W

image/vr11_Variable_Resistors.jpg image/vr2_Variable_Power_Resistors.jpg image/vr3_Power_Variable_Resistors.jpg
Dimensions (Unit: mm) Max. Resistance
A B C D E F G H I J K Weight
25W 2.5 3.2 22 3/8" 6x12 42 50 50 11 5 10 74/g 5Ω-2.5KΩ
50W 4.2 4.2 28 3/8" 6x12 64 60 70 11 8 14 160/g 7Ω-3.5KΩ
100W 4.2 4.2 42 3/8" 6x12 85 75 90 11 8 14 372/g 10Ω-5KΩ

Specifications - Variable FVR

Test Item Test Methods Characteristics
Resistance tolerance JIS-C-5261 5-1 Resistance tolerance ±10%
Insulation resistance JIS-C-5261 6-1 500VDC 100MΩ min
Dielectric withstanding voltage JIS-C-5261 7-1 1000VDC 1 minute Between terminal and axis Free of appearance or structural irregularity
Terminal strength JIS-C-5261 6-5
3kg 30 seconds
Free of appearance or structural irregularity
ΔR/R≤ ±(2%+0.1Ω)
Vibration JIS-C-5261 6-6 1.5m/m 10 ~ 50 ~ 10 Hz/min X-Y-Z 2 hours each Free of appearance or structural irregularity
ΔR/R≤ ±(2%+0.1Ω)
Load life JIS-C-5261 7-7 Free of appearance or structural irregularity
ΔR/R≤ ±(5%+0.1Ω)
Full gyration angle JIS-C-5261 6-1 300± 5°C
Flame retardation 100% - 600% rated wattage load US UL-94 flame retardation test V-0 grade noncombustible
Remarks 1. Resistance and resistance tolerance were tested in-house with micro resistance meter.
2. Coating refers to UL-certified data provided by supplier.

How to Order - Variable FVR

FVR 25W 250R K
Product type
Rated wattage
Max. Resistance Value (Ω)
R5000.500 Ω
1R001 Ω
250R250 Ω
1K001,000 Ω
2K50 2,500 Ω
Resistance Tolerance
K ±10%

Max. Resistance Value:
Max. resistance value is given to calculate the minimum resistance value because resistance value is proportional to the length of resistive wire wound along the ceramic rod.

Rated Wattage: Power rating at Max. Resistance Value.

Resistance Tolerance: Precision range of Max. Resistance Value..

1. Power Rating of adjustable resistor is determined by the maximum resistance value.
2. Resistance and Power Rating should be decreased while you are moving the adjustable lug.
3. Adjustability is 10% to 90% of full value. Wattage is proportional to this adjusted resistance value.

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FVR Series - Power Variable Resistors, Rheostats, Potentiometer