Capacitor: labelled reference, US style, sheet 1 of 1
Fig. 1
12Capacitor
A capacitor symbol stands for two conductors separated by an insulator; the two parallel plates are a picture of that.
Fig. 2
+−Polarised capacitor
In the polarised capacitor drawings here, + marks the positive terminal. The US form has a curved negative plate; the IEC form has a hollow positive plate. The marked polarity must be respected.
Fig. 3
12Variable capacitor
In the variable-capacitor convention used here, a diagonal arrow through the plates indicates adjustable capacitance.
| Fig. | Terminals | What the terminal is |
|---|---|---|
| 1, 3 | 1, 2 | A non-polarised capacitor has two interchangeable terminals. |
| 2 | + | The + terminal is the one the polarity mark names as positive. In the US form here it connects to the straight plate; in the IEC form, to the hollow plate. |
| 2 | − | The − terminal is the other side of the marked polarity. In the US form here it connects to the curved plate; in the IEC form, to the plate opposite the hollow one. |
Sources
- ModEL — Components and Symbols, §3.15 (capacitor polarity, pp. 27–28), Tony R. Kuphaldt, retrieved 2026-09-22
- University Physics, Vol. 2, §8.1 — capacitor representations, Figure 8.9, OpenStax, Rice University, retrieved 2026-09-22
- Name
- Class
- Date
- Sheet
- 1 of 1
- Drawing
- Capacitor Labelled reference
- Style
- US style
- From
- circuitsymbols.com
- Licence
- CC BY 4.0