Circuit lets you measure zener voltages and test LEDs - EDN
LED circuit - Wikipedia
High Power LED Driver Circuits : 12 Steps (with Pictures) - Instructables
Create a blinking LED circuit with a z-diode and a capacitor - Electrical Engineering Stack Exchange
LED – Light Emitting Diode - LEDs for Beginners in Electronics
LED - Light Emitting Diode: Basics, Types and Characteristics
LED - Light Emitting Diode: Basics, Types and Characteristics
Light-Emitting diode connected to 120/240 VAC - Electronics Area
Light Emitting Diode or LED Connected Using Connection Lines. Simple LED Connection Circuit Using Battery, Resistor and Circuit Stock Photo - Image of connections, circuit: 217349946
Wiring a Diode To Protect your Circuit | 14core.com
Resistors for LED Circuits | Resistor Applications | Resistor Guide
Diode circuit - worked example | Spinning Numbers
Schematic of Two-Diode Circuit | Technology Tutorials