330 Ohm 1/2W 5% Carbon Film Fixed Resistor

 

If your board needs a 330 ohm resistor, and the old part is a 1/2W carbon film part with 5% tolerance, this is the part to order. It is a 330 ohm resistor in an axial through-hole body, built for current limiting, voltage regulation, and circuit protection where a small signal resistor would run too hot. It fits power supplies, inverter repair, and general circuit work that needs a fixed 330 ohm value at up to 1/2W. It does not fit jobs that need a different resistance value, a surface-mount body, or more than 1/2W 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 carbon film resistor does that job with a thin carbon layer on a ceramic rod, which gives steady, low-noise performance for standard circuit work. This 330 ohm 1/2w resistor holds its 330 ohm value within 5%, so a board that calls for 330 ohm gets between 313.5 and 346.5 ohms. The 1/2W rating is what sets it apart from the small resistors used for signal work only — it can turn more electrical power into heat without damage, as long as the voltage and current limits below are respected.

Repair techs use a part like this as a 330 ohm resistor for current limiting, where it holds current to a safe level, and for voltage regulation, where it takes a share of the voltage so the next stage sees the right level. It also fits circuit protection work, where a fixed resistance guards the next stage, and voltage dividers, where two resistors split a voltage between them. It is an axial resistor, so it mounts through holes on a board, not on the surface. Its colour bands are orange, orange, brown, gold.

Key features

• 330 Ohm fixed resistance, ±5% tolerance
• 1/2W power rating at 70°C ambient
• Carbon film construction for steady, low-noise work
• Axial leads for through-hole mounting on PCBs and breadboards
• Maximum working voltage 300V (see the power-based limit in the checks)
• Temperature coefficient −500~+350 ppm/°C
• Wide temperature range: −55°C to +155°C

Checks before you order

• Value: your board list must call for 330 ohm. A nearby value is not the same part — 33 ohm and 3.3K ohm both look close on paper and behave very differently, so read the value twice. If your board needs a different value, stop and check the board list again. A 1K part in the same family is a different job, not a swap for this one.
• Power and heat: the power this part turns into heat must stay at or below 1/2W, and that 1/2W counts only up to 70°C ambient — above that, the safe power drops toward zero at 155°C, 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 1/2W with room to spare.
• Voltage: the voltage across this part must stay inside the limits in the table. From power alone, the working voltage for a 330 ohm part at 1/2W is about 12.8V, and the current that goes with it is about 39 mA — stay below both. Above the 300V series cap, this part is the wrong pick.
• Tolerance: the real value may sit up to 5% away from 330 ohm. If your circuit needs tighter than 5%, 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 body. Measure the old part and match it against the holes and the space on your board. The series normal-style body for a 1/2W part is about 9.0 mm long and 3.3 mm across — if your old part is much bigger, check the board list again before you order. A 330 ohm part rated 1W is the same value in a bigger body, 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 match the value first, then the power, then the body.

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).

Type	Carbon film fixed resistor, axial leads, through-hole
Resistance	330 Ohm (330 Ω)
Tolerance	±5% (313.5 Ω to 346.5 Ω)
Power rating	1/2W at 70°C
Maximum working voltage	300V
Maximum overload voltage	600V
Voltage proof on insulation	500V
Temperature coefficient	−500~+350 ppm/°C
Operating temperature range	−55°C to +155°C
Derating	Full power to 70°C; derate above 70°C to zero at 155°C
Colour bands	Orange, orange, brown, gold

Other names for the same part (good to know)

Shoppers and repair techs call this same part by a few names. 330 ohm resistor is the plain name from its value. 330 ohm 1/2w resistor is the name buyers use when the power rating matters. Carbon film resistor is the name for its construction type. Axial resistor is the name for its lead style. 330 ohm 5% is the short name that carries the value and the tolerance together. If your board list calls for 330 ohm at 1/2W with 5% tolerance in an axial 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 330 ohm mean?

It means 330 ohms of resistance. It is a middle value — low enough to pass real current, high enough to drop a useful voltage — which is why it is used for current limiting, voltage regulation, and dividers.

What does 1/2W mean, and what does 5% mean?

1/2W is the power rating: the most power the part can turn into heat without damage, rated at 70°C ambient, with less allowed as it gets hotter. 5% is the tolerance: the real resistance may sit up to 5% above or below 330 ohm, so between 313.5 and 346.5 ohms.

Can I use the 330 ohm 1W part instead?

Not as a straight swap without checking the board. The 1W part is the same value but a bigger body with thicker leads, so it may not fit the same holes and spacing. Match the power and the body as well as the value.

Can I use a different value, like 390 ohm?

No, not without checking the circuit. A resistor value sets the current and the voltage drop, so a different value changes how the circuit behaves. Only swap in a different value if the circuit design allows it — otherwise match the board list exactly.

How do I read the colour bands?

Orange, orange, brown, gold. The first two bands give the digits 3 and 3, the brown band means multiply by 10, which gives 330 ohm, and the last gold band means ±5% tolerance.

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 high-precision component for solar inverter repairing and general electronic applications, for accurate voltage regulation, current control, and circuit protection, with carbon film design for low noise and thermal stability in sensitive power circuits, used in inverter repair, power supplies, and electronic circuit design, built for durability and heat dissipation, for professionals and DIY electronics enthusiasts — and that use still stands.