Wires, junctions and meters: labelled reference, US style, sheet 1 of 2
Fig. 1
Wire junction
In the drawing convention used here, a dot marks a wire connection and a plain four-way crossing without a dot is not connected. Older drawings may use another convention, so check their legend.
Fig. 2
Wires crossing, not connected
In the newer convention used here, wires that cross with no dot are not connected. Older schematics drew connected wires as a plain crossing and made unconnected wires hop over each other with a small half-circle, so check a drawing's legend.
Fig. 3
+−Voltmeter
A voltmeter is drawn as a circle with a V and is connected across (in parallel with) the part it measures.
Fig. 4
+−Ammeter
An ammeter is drawn as a circle with an A and is connected in line with (in series with) the current it measures.
Fig. 5
12Lamp
The incandescent-lamp convention used on this sheet is a circle with a cross inside.
Fig. 6
12Motor
One common motor convention is a circle containing M; this sheet uses that form.
Notes
- The terminal key and the sources are on sheet 2.
- Name
- Class
- Date
- Sheet
- 1 of 2
- Drawing
- Wires, junctions and meters Labelled reference
- Style
- US style
- From
- circuitsymbols.com
- Licence
- CC BY 4.0
Wires, junctions and meters: labelled reference, US style, sheet 2 of 2
| Fig. | Terminals | What the terminal is |
|---|---|---|
| 3, 4 | + | The + terminal marks the side a DC meter expects to be positive: its reading is positive when this terminal is at the higher potential. |
| 3, 4 | − | The − terminal is the meter's other side. A DC meter reads positive when the + terminal is at a higher potential than this one. |
| 5, 6 | 1, 2 | This symbol has two terminals and no polarity mark. The labels 1 and 2 only tell the two ends apart. |
Sources
- Lessons In Electric Circuits, Vol. V — §9, Circuit Schematic Symbols (pp. 130–139), Tony R. Kuphaldt, retrieved 2026-09-22
- Electrical Schematics, §§1.3.1–1.3.5 — nodes, crossings, references and congruent drawings, Tufts University, retrieved 2026-09-22
- ModEL — Components and Symbols, §§3.2–3.3 (meters in series and parallel, pp. 8–11), Tony R. Kuphaldt, retrieved 2026-09-22
- ModEL — Sources and Loads, Voltmeters and Ammeters, §§4.2–4.6 and §6.2, Tony R. Kuphaldt, retrieved 2026-09-22
- ModEL — Electrical Switches, §§3.1–3.3 (pp. 16–19), Tony R. Kuphaldt, retrieved 2026-09-22
- ModEL — Components and Symbols, §3.10 (fuses and circuit breakers, p. 20), Tony R. Kuphaldt, retrieved 2026-09-22
- ModEL — Components and Symbols, §3.11 (relay example with motor and lamp loads, p. 22), Tony R. Kuphaldt, retrieved 2026-09-23
- Combined Science: Synergy, June 2022 paper — motor symbol (p. 47), AQA, retrieved 2026-09-22
Notes
- The Fig. numbers are those on sheet 1.
- Name
- Class
- Date
- Sheet
- 2 of 2
- Drawing
- Wires, junctions and meters Labelled reference
- Style
- US style
- From
- circuitsymbols.com
- Licence
- CC BY 4.0