# ANSI/IEEE DIAC form Canonical URL: https://eloragrid.ai/symbols/ansi-diac Publisher: Elora Grid Updated: 2026-10-28 Lookup label: DIAC Drawing use: Schematic Reference families: IEEE / ANSI, Manufacturer ## Symbol convention Convention: IEEE / ANSI Form: Diac Diode - Two Way Autodesk IEEE Symbol Preview: Semiconductor Components, block HDI1V3. Matching functional counterpart linked separately. Independently drawn educational geometry; not a certified IEEE glyph or database identifier. Related representation: [DIAC](https://eloragrid.ai/symbols/diac) IEEE-library form of diac: a DIAC is a bidirectional triggering semiconductor device used in a documented control circuit. ## In plain English ### What does ANSI/IEEE DIAC form mean? This reference locates diac in Autodesk's IEEE-oriented semiconductor components family. A DIAC is a bidirectional triggering semiconductor device used in a documented control circuit. Its terminals and breakover characteristics are defined by the selected component. The public library uses HDI1V3 for its horizontal representation; this is a vendor block name, not an IEEE standards symbol number. ### A simple example Follow the actual current path and terminal polarity in the surrounding circuit. The symbol identifies an electrical function; voltage, current, energy limits and the device package pinout come from the selected component data rather than from the outline. ### What the drawings help you do Follow the trigger circuit rather than treating the device as a controlled switch with a separate gate. A DIAC does not have the same controlled gate terminal as a TRIAC. 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 diac: a DIAC is a bidirectional triggering semiconductor device used in a documented control circuit. A DIAC does not have the same controlled gate terminal as a TRIAC. ### Terms - Terminal: An identified point where a conductor connects. - Rating: A value stating the conditions for which equipment is specified. - Schematic: A drawing showing function and connections rather than physical appearance. 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 — Semiconductor Components](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-EC01CFC2-47B9-4AE3-AE5E-0FB86D327A82.htm) ## What it represents This reference locates diac in Autodesk's IEEE-oriented semiconductor components family. A DIAC is a bidirectional triggering semiconductor device used in a documented control circuit. Its terminals and breakover characteristics are defined by the selected component. The public library uses HDI1V3 for its horizontal representation; this is a vendor block name, not an IEEE standards symbol number. Follow the actual current path and terminal polarity in the surrounding circuit. The symbol identifies an electrical function; voltage, current, energy limits and the device package pinout come from the selected component data rather than from the outline. Follow the trigger circuit rather than treating the device as a controlled switch with a separate gate. A DIAC does not have the same controlled gate terminal as a TRIAC. 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 - Follow the trigger circuit rather than treating the device as a controlled switch with a separate gate. - 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 - Identify connected terminals - Reference breakover rating - Show associated trigger network ## Important distinction A DIAC does not have the same controlled gate terminal as a TRIAC. ## Facts - Convention evidence: Autodesk IEEE Symbol Preview: Semiconductor Components; published form: Diac Diode - Two Way. - Public vendor block: HDI1V3. Vendor library token, not an IEEE symbol number. - Drawing role: Semiconductor function - 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 — Semiconductor Components](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-EC01CFC2-47B9-4AE3-AE5E-0FB86D327A82.htm) — Autodesk. Public IEEE-oriented Semiconductor Components table explicitly lists HDI1V3 as Diac Diode - Two Way. 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.