Go Down

Topic: 5V power source with LilyPad Micro LEDs (Read 761 times) previous topic - next topic

wmcglass

Hello there!

I've got a project where I am controlling some of the Lilypad Micro LEDs with an Arduino Lilypad 328 Main Board.  I'm powering the project with a Lilypad LiPower board and a 3.7V LiPo battery.  When I purchased the LiPower board, I didn't realize that it converts the 3.7V LiPo source into a 5V source.  I am now worried about burning out the Micro LEDs, as they do not have a resistor, and the datasheets read the forward voltage as between 2.0v and 3.3v, with a maximum of between 2.4v and 3.8v, depending on the color.  I've noticed that the LEDs are noticeably brighter than on the previous project where I used a coin cell battery.  The LEDs are connected to the Lilypad main board using 30awg wire wrapping wire, so my guess is there isn't a lot of resistance there, but I am new to hobby electronics.

All that said, should I be concerned about burning out the LEDs?  The LEDs aren't powered on continously.  The project is actually reading an analog value from a microphone and powering the LEDs based on the volume level (VU Meter), and so the LEDs power on and off multiple times a second.  Thanks in advance for your feedback!

William

CrossRoads

Yes, you should be concerned about burning out the LEDs. At higher unlimited currents their life is greatly reduced from over heating. Add some series resistors right away.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

wmcglass

Thank you for your reply, CrossRoads!  I really appreciate it.

Cheers,
William

Go Up