# ANSI/IEEE Unidirectional semiconductor power switch form Canonical URL: https://eloragrid.ai/symbols/ansi-unidirectional-semiconductor-power-switch Publisher: Elora Grid Updated: 2026-10-28 Lookup label: SSW UNI Drawing use: SLD, Schematic Reference families: IEEE / ANSI, Manufacturer ## Symbol convention Convention: IEEE / ANSI Form: 1P with Semiconductors - unidirectional Autodesk IEEE Symbol Preview: Power Switches, block HCB11Q57. Matching functional counterpart linked separately. Independently drawn educational geometry; not a certified IEEE glyph or database identifier. Related representation: [Unidirectional semiconductor power switch](https://eloragrid.ai/symbols/unidirectional-semiconductor-power-switch) IEEE-library form of unidirectional semiconductor power switch: a unidirectional semiconductor switch has a specified direction for its power conduction or control behaviour. ## In plain English ### What does ANSI/IEEE Unidirectional semiconductor power switch form mean? This reference locates unidirectional semiconductor power switch in Autodesk's IEEE-oriented power switches family. 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. The public library uses HCB11Q57 for its horizontal representation; this is a vendor block name, not an IEEE standards symbol number. ### A simple example Read the operating mechanism and the contact reference state together. Cross-reference every associated contact to the same device and show which movement, signal or reset changes its condition; the symbol alone does not establish the complete switching sequence. ### What the drawings help you do Use terminal polarity and the product circuit rather than page orientation to determine direction. Unidirectional operation concerns the circuit path; it does not describe the direction of all system power flows. The linked functional counterpart explains the same operating role in its own drawing context; agreement of every detailed convention mark is not asserted. ### This particular reference IEEE-library form of unidirectional semiconductor power switch: a unidirectional semiconductor switch has a specified direction for its power conduction or control behaviour. Unidirectional operation concerns the circuit path; it does not describe the direction of all system power flows. ### Terms - Normally open / normally closed: The contact state in the normal condition defined for the drawing. - Terminal: An identified point where a conductor connects. - Signal: Electrical information passed between devices, rather than necessarily the main power supply. Concept diagram: Identify the device and form → Read the connections and state → Check the equipment reference A guide to reading this reference. The original symbol illustration and its drawing notes appear below; these boxes are not a wiring diagram. - [Autodesk IEEE Symbol Preview: Power Switches](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-E57D79F6-E6C4-4B78-95DC-62F16642C95B.htm) ## What it represents This reference locates unidirectional semiconductor power switch in Autodesk's IEEE-oriented power switches family. 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. The public library uses HCB11Q57 for its horizontal representation; this is a vendor block name, not an IEEE standards symbol number. Read the operating mechanism and the contact reference state together. Cross-reference every associated contact to the same device and show which movement, signal or reset changes its condition; the symbol alone does not establish the complete switching sequence. Use terminal polarity and the product circuit rather than page orientation to determine direction. Unidirectional operation concerns the circuit path; it does not describe the direction of all system power flows. The linked functional counterpart explains the same operating role in its own drawing context; agreement of every detailed convention mark is not asserted. ## 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 - Convention evidence: Autodesk IEEE Symbol Preview: Power Switches; published form: 1P with Semiconductors - unidirectional. - Public vendor block: HCB11Q57. Vendor library token, not an IEEE symbol number. - Drawing role: Switching path - 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. - Artwork scope: Original educational geometry. Exact standard graphics, product ratings and terminal pinouts are not certified. ## Public references - [Autodesk IEEE Symbol Preview: Power Switches](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-E57D79F6-E6C4-4B78-95DC-62F16642C95B.htm) — Autodesk. Public IEEE-oriented Power Switches table explicitly lists HCB11Q57 as 1P with Semiconductors - unidirectional. This supports the vendor convention context, not reproduction of the publisher 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.