Slide Switch Symbol
Definition: The Slide Switch symbol represents a maintained-contact SPDT (single-pole double-throw) switch in which a sliding actuator physically moves a contact blade between two positions, used in schematic diagrams per IEC 60617 and ANSI Y32.2 / IEEE 315 to denote a component with three terminals (A, B, and C) where the common pin C is connected to either terminal A or terminal B depending on the slider position.
Also known as: SPDT slide switch, slider switch, panel slide switch, miniature slide switch, on-off slide switch.
What the Slide Switch symbol means
The Slide Switch symbol identifies a three-terminal mechanical switch whose state is set by sliding a knob or actuator along a track. In one position the common contact (C) is connected to terminal A; in the other position it connects to terminal B. A centre-off variant adds a third stable position in which C is disconnected from both A and B.
In circuit diagrams the slide switch is used wherever a compact, panel-mount or PCB-mount switch is needed to permanently select between two signal paths or to open/close a single circuit. The maintained-contact nature means the switch retains its last set position indefinitely, unlike a momentary push button.
How to identify the Slide Switch symbol
The Slide Switch symbol is drawn as a single-pole double-throw switch graphic: a common pin (C) at the centre-top, two output pins (A and B) at the left and right ends of a horizontal track, and a movable contact shown as an arrow or bar that can touch either the A or B terminal. Some simplified representations show it as two separate SPST symbols sharing a common pin, or as a rectangular block with three labelled external terminals.
Function in a circuit
A slide switch opens or closes circuit paths between its three terminals based on physical slider position. When the slider is in the A position, an electrical path exists between C and A while C and B is open. When moved to the B position, C connects to B while C and A is open. This SPDT action makes the slide switch suitable for signal routing, power-source selection, and mode switching without any separate driver circuitry.
Standards: IEC vs ANSI
| IEC 60617 | IEC 60617-07 defines switch symbols. A slide switch in SPDT configuration is represented as a two-throw switch with a maintained-contact operator symbol (no spring-return arrow). IEC 61058-1 governs the safety requirements for switches for appliances. |
|---|---|
| ANSI/IEEE 315 | ANSI Y32.2 / IEEE 315 represents SPDT switches as a single pole with two throw contacts. The designator is S (switch) followed by a reference number. ANSI/NEMA does not define a unique slide-switch symbol distinct from other SPDT mechanical switches. |
| Key difference | IEC 60617 and ANSI Y32.2 / IEEE 315 produce essentially the same SPDT switch symbol for a slide switch. The IEC symbol may include a maintained-contact qualifier; ANSI uses the standard two-throw SPDT schematic symbol. Neither standard distinguishes between slider, rocker, and toggle actuation mechanisms at the symbol level. |
Terminals / pins
| Pin | Name |
|---|---|
| a | A |
| b | B |
| c | C |
Typical values
Typical contact rating: 0.1 A at 5 V DC to 3 A at 250 V AC (PCB-mount types); 0.5 A–5 A at 125 V–250 V AC (panel-mount types). Number of positions: 2 (SPDT) or 3 (SPDT with centre off). Travel distance: 2 mm–6 mm. Contact resistance: <50 mΩ. Insulation resistance: >100 MΩ. Dielectric strength: 500 V AC. Operating life: 10 000–50 000 cycles.
Where the Slide Switch symbol is used
- Battery-powered devices: power on/off slide switch between the battery positive terminal and the supply rail
- Audio equipment: mono/stereo input selection or signal path routing on mixers and effects pedals
- Prototype and hobby electronics: mode selection, feature enable/disable, and configuration on development boards
- Consumer electronics: language, region, or sensitivity selection on remote controls and handheld devices
- Toys and novelty products: motion or sound feature enable switches on PCB-mounted assemblies
- PCB configuration jumpers: replacing solder bridges or DIP switches for factory or field configuration settings
Example
In a portable sensor node schematic, a slide switch is placed with its C pin connected to the battery positive terminal, pin A connected to the main 3.3 V regulator input, and pin B left open (or connected to a charging circuit). When the slider is in position A the device is powered on; when moved to B the main circuit is disconnected and the battery charger path is active instead.
Key facts
- The slide switch symbol has three terminals: A (one output), B (the other output), and C (common/pole) — when slider is in position A, current flows C→A; when in position B, current flows C→B.
- A slide switch is a maintained-contact device: it stays in whatever position it is moved to and does not spring back, distinguishing it from momentary-contact push buttons.
- The SPDT configuration makes a slide switch suitable for A/B selection, polarity reversal, signal routing, and power-source switching using a single component.
- PCB-mount micro slide switches are available in DIP footprints with 2.54 mm pin pitch, making them directly compatible with breadboards and standard PCB layouts without adapters.
- Contact bounce occurs when a slide switch changes position — the contacts make and break several times over 1–10 ms before settling. Digital circuits reading the switch output require debounce filtering (hardware RC filter or software delay).
- Slide switches rated for PCB mounting typically handle 0.1 A to 3 A; panel-mount types handle up to 5 A. The maximum voltage and current ratings must both be observed; exceeding either causes contact arcing and failure.
- The IEC designator for a switch is S (switch) per IEC 60617; in ANSI Y32.2 / IEEE 315 drawings the designator is also S, followed by a sequential reference number such as S1 or SW1.
Frequently asked questions
What does the slide switch symbol look like?
The slide switch symbol shows a single-pole double-throw (SPDT) configuration: a common pin C at the centre connected by a movable contact bar to either terminal A or terminal B. The two throws A and B are at opposite ends of a horizontal track, and the sliding contact indicates which of the two positions is selected.
What does the slide switch symbol mean in a circuit diagram?
The slide switch symbol means there is a maintained-contact SPDT switch that physically connects its common terminal (C) to one of two output terminals (A or B) based on the physical position of its slider actuator. The switch retains its selected position until manually moved.
What are the three pins on a slide switch?
The three pins are A (first output terminal), B (second output terminal), and C (common or pole terminal). In position A, C is electrically connected to A and disconnected from B. In position B, C is connected to B and disconnected from A.
What is the difference between a slide switch and a toggle switch in a schematic?
Both a slide switch and a toggle switch are SPDT maintained-contact switches and use the same schematic symbol in IEC 60617 and ANSI Y32.2. The difference is purely mechanical: a slide switch has a linear sliding actuator; a toggle switch has a lever that tilts. The electrical function and schematic symbol are identical.
What standard defines the slide switch symbol?
IEC 60617-07 defines graphical symbols for switches including SPDT types. ANSI Y32.2 / IEEE 315 provides the North American equivalent. Safety requirements for switches in appliances are specified in IEC 61058-1. No standard defines a unique symbol exclusively for slide switches as distinct from other SPDT switch actuator types.
How do I debounce a slide switch in a circuit?
Hardware debounce: place a 10 kΩ resistor from C to VCC (or GND) and a 100 nF capacitor from the switch output to GND; the RC time constant (≈1 ms) filters the bounce pulses. Software debounce: after detecting a state change, wait 10–50 ms in firmware before reading the final stable state.
What is the current and voltage rating of a typical slide switch?
PCB-mount micro slide switches are typically rated 0.1 A to 3 A at 5 V DC to 250 V AC. Panel-mount slide switches handle up to 5 A at 250 V AC. Always check both the voltage and current ratings of the specific part; exceeding either causes contact arcing, increased contact resistance, and premature failure.
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