LDR
Light-dependent resistor
A light-dependent resistor changes resistance according to illumination.
SLD / Schematic
IEEE / ANSI · LDR
ANSI/IEEE light-dependent resistor symbol
IEEE-oriented graphical reference for light-dependent resistor, with public vendor evidence and drawing-reading notes.
IEEE / ANSI · Autodesk IEEE-oriented Resistive Components functional form
Autodesk explicitly publishes this block under IEEE Symbol Preview. The counterpart is the matching functional concept; no equivalence of every detailed standard graphic is asserted.
Shown as an independently authored educational illustration. Use the cited publication and drawing legend to verify the required drafting form.
SLD / Schematic · LDR
What it represents
The light-dependent resistor form identifies a resistive component affected by illumination. Its sensing modifier describes the physical influence rather than a new electrical terminal, while the surrounding circuit translates the resistance change into a usable signal.
This is a convention-specific lookup based on the publisher's IEEE-labelled preview. The geometry here is independently drawn to explain the connection or operation; it is not a certified reproduction of the standard graphic.
How to read it
- Trace the electrical leads independently of the optical indication.
- Read the selected library and the project legend together. A vendor block identifier is meaningful within its named library and is not a universal standard-symbol code.
Information to show or reference
- Identify resistive terminals
- Reference illumination conditions
- Show associated sensing circuit
A distinction that matters
An LDR changes resistance; a photodiode has a semiconductor junction and different measurement behaviour.
Sources you can follow
These public references support the explanation and provide further detail. Their graphics and downloadable files remain with their publishers.
Autodesk IEEE Symbol Preview — Resistive Components
Exact public IEEE-oriented category page verifying the component name and vendor block identifier.
IEEE/ANSI 315-1975: graphic symbols for electrical and electronics diagrams
Graphic-symbol standards context and official status; not a source of reproduced artwork.
About this graphic
This illustration was authored independently by Elora Grid to explain the concept. It is not reproduced from a customer drawing, an official standard graphic or a manufacturer CAD file. Its correspondence to an exact IEC or IEEE symbol identifier has not been certified.
SVG and DXF downloads contain this original artwork. DXF uses unscaled drawing units; a GA envelope supplies no product dimensions, clearances or fabrication information. Original artwork is available under CC BY 4.0. Third-party references retain their own terms.
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