Posts tagged ‘LED’

Blue LED pumping out light while powered by Joule Thief.

Blue LED pumping out light while powered by Joule Thief.

Continue reading ‘Joule Thief Powers ANY Color LED’ »

Handmade Toroidal Inductor

Handmade Toroidal Inductor

How does the number of turns in the toroidal inductor affect the performance of a Joule Thief?

Continue reading ‘Toroidal Inductors – Number of Turns Affects Joule Thief’ »

When driving LED’s with a microcontroller, chances are you won’t have enough power coming out of the microcontroller’s pins to power an LED. For example, the TI Launchpad MSP430 only allows for a reliable 1.5mA of power out of each pin. To drive an LED, you might want more like 20mA. So you will need an external circuit to safely drive the LED.

Circuit I used to drive an LED with TI Launchpad MSP430.

Circuit I used to drive an LED with TI Launchpad MSP430.

Read on and see the video.

Continue reading ‘Calculate Resistor Values for Driving LED’s’ »

calculate-forward-voltage-of-LEDs-red

It is simple to measure the forward voltage of an LED.  You just need an appropriate choice of battery and resistor.  Read on and see the video…

Continue reading ‘Calculate LED Forward Voltage’ »

Velleman sells a kit that you can build, advertised to be a sound indicator.  “…simple sound-to-light unit for music, the hard of hearing:  can be used to indicate the telephone, doorbell, barking dog.  Adjustable sensitivity with potentiometer…“  We built the MK103 kit and made a video showing a product test and review.

Continue reading ‘LED Sound-to-Light Unit Review’ »