Saturday, June 24, 2017

Building a 5V Transient Tester for USB Power Analysis

One part I find myself using somewhat regularly in projects is a lithium battery bank charger/USB power supply - it's the guts of a battery bank phone charger, except always turned on.  This provides a reliable 5V output for projects, charges from micro-USB if needed by the project, and offers some basic battery protection behaviors (on paper, they should turn off below a certain input voltage and stop charging over another voltage).

However, while fighting with the SparkFun ESP8266 WiFi Shield, I discovered that these units do not handle transients very well - if the load changes quickly, the voltage wanders around for a while before recovering.  Different units behave differently, and I wanted to find out how different testers behave under this type of load - so I built myself a USB 5V Transient Tester!


Why?  Because!  I wanted something that did this, couldn't find one easily available, and set out to build one.  This is the sort of one-off bit of lab equipment that Arduinos are perfect for.

Interested?  Read on!


Saturday, June 17, 2017

Building Ural-compatible PVC Target Stands for about $25/ea

You know what you need?  Cheap target stands for range days!  You can build a pair of these stands for just over $50 in parts from your local Home Depot or Lowes.

I built this pair in just over an hour.  Most importantly, they fit on my Ural!


If you find yourself needing some cheap target stands on short notice, read on!

Saturday, June 10, 2017

Solar Shed Part 16: Interior & Exterior Improvements

My solar powered office has been up and online for a while, but one of the joys of a space like mine is that it's always a project - and I can do whatever I want with it, constrained only by what is possible affordable and what I can figure out how to do!  For instance, I'm almost, but not entirely, out of space for more monitors.


This space is totally awesome for what I do with my time - it's working absolutely as well as hoped, and I have no significant complaints.  But, I have been making improvements as I go to make the space better for my needs.  Read on for some of the changes I've made since the original post last July!

Saturday, June 3, 2017

Solar Shed Part 15: Surviving the Winter (Heating)

Winter is a cold time of the year - and in my solar powered office, the lack of sun in the winter can pose some serious problems for keeping the place warm.  Even with good insulation, I need some heat!

My original plan for heat involved using my air conditioner/heat pump/resistive heater paired with an awful lot of optimism about solar production in the winter.  You may be able to guess that if I'm writing a whole post on heating, this plan did not work quite as well as I'd hoped...

And you'd be right.  My wall unit is great - but I didn't get enough sun to keep me warm all the time.  In other ways, it was too powerful for winter use.  But, I've found solutions!  And as you can see, they work rather nicely!


Read on to find out what I figured out to stay warm in the winter!

Saturday, May 27, 2017

DeWalt NiCd Tool Battery Teardowns

It's the last week in May - so the last week of tool pack teardowns for a while.

This week, I've got a huge pile of older DeWalt 18V NiCd batteries (and a lone 14.4V battery) that need to come apart so I can remove them from my office and get some space back.

I've got a 14.4V XR pack, a stock 18V pack, an 18V XR pack, an 18V XR2 pack, and an 18V XR+ NiCd pack.  They look pretty similar on the outside, but the similar form factors conceal some (very) minor interior differences!


Are you interested?  Well, if you've seen one NiCd pack, you've seen most of them - this is not one of my more exciting posts.  But, read on if you're curious.

Saturday, May 20, 2017

Ryobi One+ Lithium & NiCd Tool Battery Teardown

It's still May, and I'm still doing tool pack teardowns to get through the seemingly endless boxes of tool batteries in my office.  I'm a bit fuzzy on where they all came from, though I do faintly recall picking up a box of dead ones at some point in the past.

This week, I have a pair of Ryobi One+ batteries - one lithium, one NiCd.  This represents the "old generation" and "new generation" of a generation of batteries - they both run in the 18V tools, but one is the old style NiCd, and one is a new style lithium (though, as you'll see, early lithium).


Join me as I rip into another two packs!


Saturday, May 13, 2017

DeWalt 20V Max 1.3Ah and 18V Nano Phosphate Teardown

Another week in May, another pair of tool packs in my series of tool pack teardowns!

This week, I'm back to DeWalt with a 20V Max 1.3Ah, and an older 18V "Nano Phosphate" pack - which has the weirdest cell layout I've ever seen.  The date code says 2007 - so this is another example of an early tool pack in the "Working out the details" phase of lithium tool packs.


Join me as I rip into another two DeWalt lithium battery packs!