Friday, 5 December 2014

Improved Current Load

Some Free Advice!

Back when I write about my failure to build a current limiting circuit for my Alarm Panel Interface, Zega was kind enough to offer me some advice.

Long story short, half the oscillations I was chasing in my limiting circuit were due to my quick and dirty Constant Current Load.  

Here's the Problem...

Thursday, 4 December 2014

nrf51822 QFN48 Reference Design

Giving Back

The other day I was looking at my blog stats, I was surprised to find that my KiCAD posts were linked to, where someone was wanting help converting an Altium reference design into KiCAD.

So, I thought I'd help out - here's the reference designs, converted to KiCAD PCB.


Tuesday, 2 December 2014

KiCAD Tidbits

KiCAD, For Profit!

I recently picked up a small contract for a board design, and the client wanted to use KiCAD.

I'd dabbled with KiCAD before, and even though I wont favour it over Altium, it's still a useful package, at a great price :)

But, it's not without it's quirks.

All About The Angles

Wednesday, 15 October 2014

Bright Light

The Workshop

At home I've seconded a small corner of my garage for my work space.  

You could describe it as 'spartan' or 'functional' but in reality, 'cheap' is more accurate.  One problem with the bench is that it's poorly lit.

Saturday, 16 August 2014

Altium MultiChannel

Multi-Channel Rules

Just recently I was reading this post on the EEVBlog forum and thought "Ah ha!  I've done this before." Should be easy.  Famous last words.

So after spending a ridiculous amount of time workign out what the missing step was, I thought I'd better capture it for the next time I want to use it.


You use a multi-channel design in Altium when you have multiples of an identical sub-circuit.  QAll you need to do is lay out the one channel, and then you can duplicate the layout by 'Copy Room Formats".  This has saved me a ton of time in the past.


Altium uses a complex naming convention:

Monday, 4 August 2014

Multi Channel Meter, Part 2

From Idea to Implementation

What I really love about my hobby projects is that I can develop answers to questions that I can't explore at work.  20kW HF transmitters, Radar Installations all over the world, and Cutting Edge elemental analysers?
No worries.

Digitally Controlled GainIsolated PSU Choices?  Fergedaboudit.

In part 1, I detailed my path from the concept of a multi-channel volt meter, to a working system based on individual modules.  Here I'd like to talk about how I refined the design into my first prototype and then look at where I'm going from there.  Like Art, Engineering is never finished, you just chose a point to stop...

Sunday, 27 July 2014

Multi Channel Meter

So after all that background...

Recently I've blogged about DIY Isolated Supplies and Microcontrolled Analogue Gain, as these have been necessary building blocks for my latest project - a multi channel voltage / current meter.