Sharing the Love

Share Alike

Today I was asked if I could share my soldering iron hack PCB.

So I did!

PSU Console

Dead Simple Power Supply

At work I'm quite spoilt, there is an abundance of equipment in the labs, and if I need, I can borrow something for home use.  Very handy when ding something specific (like the thermocouple I used here) but it comes with a down side.

If I realise I need something, it means dropping work for a few days until I can borrow the equipment (if it's in use at work, I can't have it until it's free) and as I catch the train, it also means bringing the car in if it's too big to fit in my backpack.

When it came to powering my projects, I have a very basic dual rail Power Supply (I built one just like in in Uni, tortured it to death over the coming years by running a car amp from it in my bedroom) that I inherited from a guy-who-got-it-from-a-guy-from-a-garage-sale deal.

The updside: It's got dual isolated rails, 1.25V to 15V range and 'up to' 1A output.  

The downside: It's so old the pots are scratchy, so setting an output voltage is a chore, and there isn't any current limit.  And you need to whip out your multimeter to set the voltage / measure the current in use.

So I got cracking on this:

Improved Current Load

Some Free Advice!

(Update - July 2019 - see the end of this post regards how not to blow this up!).

Back when I wrote 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...

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

Isolation Options

Isolated PSU

So if you find out you need to isolate your circuit, you will need to power it over the isolation barrier, and there are options out there to do that.

Finding myself in that position, and being a notorious tight-arse I started to look at DIY options.

10 Years On

DIY Trailer LED Lights

About 10 years ago I built a pair of LED trailer lamps for my Father In Law. This was back when LED lights were stupidly expensive - and as luck would have it I had access to some high brightness samples. 

Anyway, the lights served their time in the harsh conditions of the Riverland and the plastic lenses finally turned more opaque than useful. 

After replacing with a set of lamps off eBay for less than $40 I thought I'd share what they look like now. 

Closing the KiCAD Gaps

Imports and Persistence

As discussed before, I'd decided to try KiCAD for the first time and the approach I took as to port an existing design, in this case EEVBlog's uCurrent.

To recap, I'd produce a schematic that still needed it's annotation and part values updated, and I'd also imported the Altium PCB files into KiCAD, with an Altium to P-CAD conversion as an intermediate step.

New Boards!

New Boards

My next bunch of boards from Seeed studio have arrived.  Here's some shots of parting out the prototypes from 10 x 15 cm panels.

Build and test info coming... as soon as I build and test.

What's All This KiCAD Stuff, Anyhow?

Going Open Source CAD

As can be seem from various post's here, I'm an Altium user.  I'm lucky enough to have access to it work, and I've been using it since it was good old Autotrax for DOS.   Yes, I'm that old....

For work that's fine but with my home projects I'm keen on sharing these as Open Source Hardware and releasing designs in Altium goes against the grain here - the community prefers that you share using open source tools.

So with this in mind, I decided to take the plunge and try KiCAD.  My following thoughts will be comparisons between 'what I know' about Altium and what my impression are about KiCAD and I fear it will be far from fair.  Altium does set the bar, and thus my expectations of what a PCB CAD tool can do, pretty high...

It Can Be Done!

And besides, I need something to do while I wait for my next revision of Alarm PCBs to land....