Side-by-side reference

Understand the difference.

Compare the meaning, drawing context and source references of two entries. A similar graphic or shared abbreviation does not establish equivalence.

First referenceCompare with

LDR

Symbols

Light-dependent resistor

A light-dependent resistor changes resistance according to illumination. The schematic places the sensing element in its actual electrical network and the equipment detail identifies the illumination conditions.

Drawing use: SLD / Schematic
Application: Control circuits
Reference family: IEC / Manufacturer

A distinction that matters

An LDR changes resistance; a photodiode produces a different semiconductor sensing response.

Full reference

Symbols

Resistor

A resistor representation identifies a resistive component in a circuit. Different drawing conventions can use different basic outlines, while additional qualifiers distinguish variable resistors, shunts or heating elements. The value, rating and purpose are separate annotations.

Drawing use: Schematic
Application: Control circuits
Reference family: IEC / IEEE / ANSI

A distinction that matters

IEC-style rectangular and other conventional resistor depictions can describe the same component concept, but qualifiers and documentation still matter.

Full reference

Original educational previews. Follow the source references on each full entry for the appropriate standard or selected product.