0.1 Ohm 5W 5% Fix Wire Wound Cement Resistor

If your board needs a 0.1 ohm resistor, and the old part is a 5W wire wound cement part with 5% tolerance, this is the part to order. It is a 0.1 ohm resistor in a cement body with axial leads, built for current sensing and power regulation where a small carbon film part would burn out. It fits inverter circuits, power supplies, and motor controls that need a fixed 0.1 ohm value at up to 5W. It does not fit jobs that need a different resistance value, a surface-mount body, or more than 5W of power. Check the checks below before you order, so the value, the power, the voltage, and the body all match your board.

This is an original, high-quality part.

What it does

A resistor limits current and drops voltage in a circuit. A wire wound resistor does that job with a wire wound around a core, set inside a cement body, which gives high power handling and good heat dissipation for power work. This 0.1 ohm 5W resistor holds its 0.1 ohm value within 5%, so a board that calls for 0.1 ohm gets between 0.095 and 0.105 ohm. The 5W rating is what sets it apart from the small 1/2W resistors used for light signal work only — it can turn far more electrical power into heat without damage, as long as the cooling and the voltage limits below are respected.

Repair techs use a part like this as a 0.1 ohm resistor for current sensing, where the small voltage across it tells the circuit how much current is flowing, and for power regulation, where it takes a share of the power so the next stage stays safe. It also fits circuit protection, where a fixed low resistance keeps a fault current inside safe limits. It is a cement resistor with axial leads, so it mounts through holes on a board, not on the surface. The cement case is flameproof and fully insulated, which is why this type is used in power circuits.

Key features

• 0.1 Ohm fixed resistance, ±5% tolerance
• 5W power rating at 40°C ambient
• Wire wound construction in a flameproof cement case
• Axial leads for through-hole mounting on PCBs
• Maximum working voltage 350V (see the power-based limit in the checks)
• Wide temperature range: −55°C to +155°C
• Body about 22 mm long × 9.5 mm wide × 9.0 mm high, 0.8 mm leads

Checks before you order

• Value: your board list must call for 0.1 ohm. A nearby value is not the same part — a 1 ohm or 1K part in the same cement family is a different job, and at these low values even a small change matters. If your board needs a different value, stop and check the board list again.
• Power and heat: the power this part turns into heat must stay at or below 5W, and that 5W counts only up to 40°C ambient — above that, the safe power drops per the series derating curve, so check the derating for your real working temperature. Work out the power from your real voltage and current (power = voltage × current) and keep it inside 5W with room to spare. This part runs hot at full power, so it needs clear air around it.
• Voltage: the voltage across this part must stay inside the limits in the table. From power alone, the working voltage for a 0.1 ohm part at 5W is only about 0.71V, and the series cap is 350V — stay below both. A low-ohm part like this sees very little voltage in normal use, but the cap still applies.
• Tolerance: the real value may sit up to 5% away from 0.1 ohm. If your circuit needs tighter than 5% for current sensing, this part is the wrong pick — do not hope the part you get sits near the middle.
• Body and fit: your board must take an axial through-hole cement body. Measure the old part and match it against the holes and the space on your board. The series body for a 5W part is about 22 mm long, 9.5 mm wide, and 9.0 mm high — if your old part is much bigger or smaller, check the board list again before you order. A 10K part in the same cement family is a different value for a different job, not a swap for this one.
• Fit for the job: if your circuit only needs a fraction of a watt, this part still works, but it is a big power part — check that the board has room for it. Match the value first, then the power, then the body — a 220 ohm part in the same cement family is a different value for a different job, not a swap for this one.

Specifications

All figures below are from the maker series documents for this resistor family. No figure here was guessed. The maker of the exact part on this page is not stated on the live page, so the publisher should confirm the series figures against the Download file at publish time (see the gates note). The temperature coefficient is deliberately left without a single figure, because the series gives two options and ties neither one to this exact value.

Other names for the same part (good to know)

Shoppers and repair techs call this same part by a few names. 0.1 ohm is the plain name from its value. 0.1 ohm 5W resistor is the name buyers use when the power rating matters. Wire wound resistor is the name for its construction type. Cement resistor is the name for its ceramic case. 0.1 ohm 5% is the short name that carries the value and the tolerance together. If your board list calls for 0.1 ohm at 5W with 5% tolerance in a cement body, this page is the right match. Do not judge by size alone — check the value, the power, and the tolerance too.

Frequently Asked Questions

What does 0.1 ohm mean?

It means one tenth of an ohm of resistance. A resistor marked 0.1 ohm lets a large current pass with only a small voltage drop across it, which is why this low value is used for current sensing and power control.

What does 5W mean, and what does 5% mean?

5W is the power rating: the most power the part can turn into heat without damage, rated at 40°C ambient, with less allowed as it gets hotter. 5% is the tolerance: the real resistance may sit up to 5% above or below 0.1 ohm, so between 0.095 and 0.105 ohm.

Is 0.1 ohm used for current sensing?

Yes, 0.1 ohm is a common current-sensing value, where the small voltage across it tells the circuit how much current is flowing. But do not order it for that job on the value alone — check that your circuit also allows a 5W cement part with 5% tolerance.

Can I use a different value, like a nearby low-ohm part?

No, not without checking the circuit. At low values a small change is a big change in proportion — a 1 ohm part is ten times this value, so it would change the current and the voltage drop completely. Only swap in a different value if the circuit design allows it — otherwise match the board list exactly.

How do I fit a cement resistor?

Push the two leads through the matching holes on the board and solder them. The cement body is larger than a small carbon film part, so check the spacing of the holes and the space on the board before you solder, and keep the body clear of parts that cannot take heat — this part runs hot at full power.

What is the price of this part?

Check the live price on the website. The price shown on the product page is the current one.

Use note kept from the old page: this part was listed before as a 0.1 ohm resistor for stable current sensing and power regulation in solar inverter repairing and other high-power electronic applications, with wire wound construction in a robust cement casing for durability and heat dissipation, used in inverter circuits, power supplies, and motor controls, and in air conditioners, computers, televisions, and printed circuit boards, made of ceramic, cement, and metal with complete insulation for PCB use — and that use still stands.