5mm indicator LED, blue, diffused, 15mm leads *new*

Basic 5mm indicator LED, which can be found in a vast amount of various electronic devices. Simple and elegant solution for communicating various information to humans (Or perhaps animals... We presume it varies from user to user), such as power on status, error status, signal presence, certain voltage presence, device ready status or some sort of an ongoing alarm indication.

Disregarding what on earth you are going to use these for here’s a few tips how to use it.

• Typical indicator LED operating current is ~5...15mA, even though it can operate even up to 30mA current. LED brightness difference between 15mA and 30mA is so low that there is no point on flooring the LED on full blast.
• How to calculate current limiting series resistor for one LED:
  • R=U-U_{LED threshold voltage} / I_LED
  • In layman terms, subtract LED threshold voltage from your operating voltage (usually your power supply or device output’s voltage) (voltages in volts) and divide the result by your desired amount of current in amps. As a result you will get your resistor value in ohms
• How to calculate series resistor for multiple LED’s:
  • R=U-(U_{LED1 threshold voltage} + U_{LED2 threshold voltage....)} / I_LED
  • In layman terms same thing as bellow, but add up all of the LED’s threshold voltages together and subtract that from your operating voltage.
• Remember to check that the resistor power dissipation will not scorch the resistor, and here’s how to calculate the power dissipation of a resistor:
  • P=U_resistor*I
  • In layman terms, use the voltage you counted up previously and multiply it by the current in amps. Your result is in watt’s. Compare that result to your intended resistor’s max power rating. Typical small resistor power ratings are 1/8W (125mW), 1/4W (250mW), 1/2W (500mW), 1W and so on...
• And then remember the right polarity!... Or your creation shall not glow!

LED’ technical details:

• Color:
  • Blue, diffused
• Threshold voltage:
  • 2.9VDC
• Max current:
  • 30mA
• Recommended forward current:
  • 5...15mA
• Beam angle:
  • 120°, diffused
• Polarity:
  • Long lead:
    • Anode (+)
  • Short lead and flat edge:
    • Cathode (-)
• Luminous intensity:
  • Wild guess, enough to indicate something on appliance but way too dim to light up things
• Min lead length:
  • 15mm