# Unidirectional semiconductor power switch

Canonical URL: https://eloragrid.ai/symbols/unidirectional-semiconductor-power-switch
Publisher: Elora Grid
Updated: 2026-10-13
Lookup label: SSW UNI
Drawing use: SLD, Schematic
Reference families: IEC, Manufacturer

A unidirectional semiconductor switch has a specified direction for its power conduction or control behaviour.

## What it represents

A unidirectional semiconductor switch has a specified direction for its power conduction or control behaviour. The functional direction must be identified so reversing a schematic orientation does not reverse the intended meaning.

## How to read it

- Use terminal polarity and the product circuit rather than page orientation to determine direction.
- The preview is an original explanation of this function. Match the actual drawing convention to its legend and the selected equipment documentation.

## Information to show or reference

- Show permitted conduction direction
- Identify control polarity
- Reference reverse-voltage capability

## Important distinction

Unidirectional operation concerns the circuit path; it does not describe the direction of all system power flows.

## Facts

- Drawing role: Switching path
- Representation scope: Functional concept; not an official standard graphic or a product footprint
- Public vendor block reference: HCB11Q57, VCB11Q57 (Autodesk identifiers; not IEC symbol numbers)
- Identifier status: The short label is a functional lookup label, not an assigned IEC or IEEE symbol number. Any separately listed Autodesk code is a verified vendor block name.

## Public references

- [AutoCAD Electrical: Power semiconductor switches](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-54E4231E-F794-4527-9104-C2D7BA312077.htm) — Autodesk. Public documentation of this equipment function or named vendor variant; the illustration is independently authored and is not the source graphic.

## Graphic scope

Independent original educational concept illustration by Elora Grid. Not a certified standards graphic or manufacturer footprint. Unitless; not to scale. Original artwork licence: https://creativecommons.org/licenses/by/4.0/. Publisher material is linked only.