Film (polyester/polypropylene) · Exterior view

104J = 100 nF ±5%Plastic case (PBT) · 7.2 × 2.5 × 6.5 mmPins · 5 mm spacing

Red or yellow rectangular box, or green drop body, with the “2A104J” code on top
Varies with the value; 100 nF box type is a few mm, lead spacing 5 mm

Capacitors

Film (polyester/polypropylene)

In simple terms

What is this?

A stable capacitor made with plastic film; a calm, reliable bucket.

What is it for?

It keeps its value in timing and audio circuits; the tone and the duration do not drift.

Where do you see it?

In audio amps and timing circuits.

How do you spot it?

A small box with two legs; a code made of letters and numbers is printed on it.

Caution:

Do not use it as a substitute for an electrolytic; its value is much smaller, so read the code on it correctly.

Technical definition

A non-polarized capacitor made by winding a thin metal-coated plastic film (polyester or polypropylene). Its value changes little with temperature and voltage, and its loss is low. It is larger than ceramic but more stable.

Capacitance100 nF

Voltage100 V

PolarityNone

Schematic symbol Same in IEC and ANSI

IEC 60617: the drawing style used in Türkiye and Europe.

Pins 2

1Pin 1Has no direction1

2Pin 2Has no direction2

Features typical

Capacitance range: 1 nF – 10 µF
Voltage: 63–630 V
Tolerance: ±5% (J) · ±10% (K)
Polyester: Small, cheap, general-purpose
Polypropylene: Very low loss; audio and pulses
Self-healing: Available in metallized types
Warning: X2 types are for mains; mains is outside this app's scope
Example part: 2A104J (100 nF, 100 V, ±5%)

Common mistakes

Reading the code wrongThe “2A104J” on the body says: 2A = 100 V, 104 = 100 nF, J = ±5%.

Using it in place of an electrolyticA film capacitor has a large volume per µF. It is not suitable for supply filters that need hundreds of µF.

Test with a multimeter

Test whether this part is good with the multimeter on the measurement screen.

Take a measurement

Where it is used

555 timing capacitorAudio coupling and tone circuitRC filterSuppressing motor noise