Posts tagged electrical-engineering

LED I-V Curves

I thought it would be fun to do some quick-and-dirty measurements of the I-V characteristic of some LEDs I had laying around. I have no idea where they came from, but one is red and one is white.

Fun fact: white LEDs, which of course would require many junctions of varying bandgap to produce white light directly, are often implemented by coating a blue LED in a phosphor that downconverts some photons into the rest of the visible spectrum.

../../_images/red-led-iv.png

Read more ...


Modeling copper losses in a boost converter

This post will work through a simple power electronics problem. An ideal boost converter uses only lossless components (L, C) and no lossy components (R). However, real inductors will have nonzero resistance in its wiring. This copper loss has a strong effect on the converter’s ability to boost voltage. This follows the approach of Chapter 3 of Fundamentals of Power Electronics, 2e by Erickson and Maksimović.

First let’s draw the boost converter we’ll be modeling. Note that in this context, the precise switching circuit (PWM driver, MOSFET, etc) is irrelevant and represented by an ideal switch.

Read more ...