Eric Holland

Most of my Blog posts involve short 3-4 hour projects/hacks that I just build up for learning and fun. I thought it was time to develop something a bit more involved and share my design process in a series of posts over the next few months.

I have lots of test…

Most people in the Embedded Electronics world view discrete RF Design as “Black Magic”. I would agree RF is complicated, but it isn’t Black Magic. The magic is that when you are dealing with signals in the RF frequency range the “small things” matter; my little experiment below proved that to me…

In my last blog post I took an Adruino Uno and a Protoshield and made a simple battery monitor, so I could measure the voltage of a discharging 9V battery when it was drained through a constant 100mA load. Below…

Trying to figure out the capacity left in a battery based on only its voltage is difficult. The equivalent-series-resistance (ESR) of the battery makes the cell’s voltage a function of the current that is being drawn from it. For this reason I like to measure and plot the discharge of a battery, I…

I have been slowly reading through Jim Williams “Analog Circuit Design” book. Not slowly because it is boring, it is actually very interesting and a good read; I just get easily distracted and it has been a few weeks since I picked it up. I am about 200 pages or so into it and my favorite chapter…

It is Sat. afternoon, mom is in Kentucky visiting family and I have the girls……. what should we do? A 555 timer based Rudolph the Red-Nosed Reindeer of course!

I grabbed some scrap double sided PCB material and cut out a cookie cutter like reindeer shape.

Then I had my 4-year old…

Last week I saw a neat post from Johngineer where he took an Arduino and a couple RC filters and made a Xmas Tree on his scope.

I thought this would be a fun project to replicate with my 2 and 4 year old daughters, but I wanted to make a small tweak and…

Back in October I managed to get my 7400 Logic PLL Based Switcher in the third place category of the “Dangerous Prototypes Open 7400/4000 Series Logic…

Lately I’ve been soldering quite a bit at home and thought a fan based fume extractor would be a good investment. I came across this MAKE video recently that describes how to build one that fits in an Altoids box.
MAKE Video

I…

I actually heard about the contest while listening to a weekly electronics radio show, TheAmpHour. Chris and Dave, the two radio hosts, were ranting about how strict the design contest rules were. Each entry had to use one or more Touchstone Semiconductor TS1001 low power…