Voltage drop is usually 1.9~2.1V for AlGaInP, 3.1~3.5 for InGaN and 1.2V for Infrared.
Current is usualy 20mA, for UFO LEDs current is: 30mA for InGaN and 50mA for AlGaInP.
Supply Voltage - depends what you have at disposal. Usuall is 6V or 12V source.
Leds in series:
Leds in parallel:
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