Wednesday, December 30, 2015

Building a Model Train Power Supply - Part 2

Incase you got here from Google and missed it, Part 1 of this build is here.

So I needed to get 1/4" material that would take laser engraving well and not be expensive. I took a chance on using Sande Plywood. It's a material sold at Home Depot in 4' x 8' sheets. After cutting the 4x8 sheet lengthwise, then ripping that into 12" strips using a table saw, I was ready to put the strips into this:

This Epilog Mini is available for use in the basement of the Cleveland Public Library in their maker space called Tech Central. I scheduled a time to use the machine, made sure my drawings fit onto the 12" x 20" sheets (the maximum "printable" area of the laser engraver), and got started. About 90 minutes later, I had not only cut the parts of the power supply box, but also was able to engrave some signs to put on the doors of my daughter's bedrooms as Christmas gifts.

So, here are the pieces cut out of the Sande Ply:

Next I stained the plywood with a Minwax Natural Stain:

Then apply a Minwax Quick Drying Polyurethane:

Now, assembly! I modified the buck converter that I bought from Amazon by removing the 50K trim pot (I removed it to measure it's resistance) and soldering a wire jumper to a panel mountable 50K pot I got from my local MicroCenter.

Now solder on the 3 wire voltage meter powering it with the 24v coming into the DC-DC converter and measuring the output:

Then install the power switch/fuse/jack and the neon light:

After doing some soldering and hot gluing the voltage meter in, here is where we're at:

You'll notice that I have 2 binding posts that aren't hooked up. I mean for them to be 5v & 12v respectively but I didn't have enough time to build the regulator circuit for the posts just yet. That will be resolved soon.

Since some of the parts I needed to solder were rather large (compared to soldering parts on a PCB) I had to use a much larger soldering iron to get the volume of heat I needed. So, I busted out an old school soldering iron that is certainly much older than me:

So after installing the knob for the speed control pot, here is the "finished" product:

And here it is hooked up to the train set, but after I already removed the live Christmas tree.

My girls enjoyed playing with it which is all I could hope for. I suppose, I could use the power supply as a makeshift bench power supply in the off season...

Tuesday, December 29, 2015

Building a Model Train Power Supply - Part 1

For a number of years I have owned a G Scale train set from Bachmann. Here is an example of the set:

If you have never seen a G Scale train set, it is quite large at a scale of 1:22.5. Another name for G Scale trains is Garden Railway. Unfortunately, I haven't had a workable power supply that would produce enough current to drive the train set. When I looked at buying a manufactured power supply from MRC, such as this:

The price of the power supply is around $260USD, holy crap! So that's out, time to build one I guess. After determining that the track voltage can get up to 21v and I would need at least 5 amps of current, I settled on using a power supply that I recently picked up from an electronics surplus store.

So, I start collecting some parts, and needed to get working on an enclosure. My plan was to have this power supply built by Christmas so that my kids can play with the train set for a few days before it & the Christmas tree go away for the season. Here are the parts that I collected for this project:

After taking some measurements, I decided to build a box that was 7 inches wide, 5 inches tall and 11 inches long. This should be enough space to fit all of the parts. I used Box Maker to get a drawing of the correctly sized parts that would be made with 1/4" plywood material cut in a laser cutter/engraver.

After measuring the electronic parts (power supply, buck converter, binding posts, voltage readout) I updated the Box Maker drawing to include holes for ventilation, knockouts and mounting screw holes.

Here is what the drawings look like prior to cutting. The top & bottom of the box:

The sides of the box:

That's it for now. In the next post, I'll go over the material I used for the box as well as finishing the plywood and assembly.

Wednesday, December 2, 2015

CodeMash 2016 Submissions - The Followup

A little late on this, but yeah, didn't make the final cut with my submissions. A number of us at LeanDog submitted talk ideas and didn't make it, but be sure to look for talks & pre-compilers from Charlotte Chang, Nicole Capuana, Doug Morgan, and Kyle McKee.

I am planning on submitting ideas/scheduling time for Open Spaces with hardware & IoT related topics. Keep an eye out for them!

Monday, August 31, 2015

CodeMash 2016 Submissions

Well, CodeMash 2016 is quickly approaching. So, what better time than to submit your talks. As I write this, we have just under 2 hours left to submit talks & precompiler ideas.

I am submitting ideas for:
  • Designing a PCB Pre-Compiler
  • UART, I2C & SPI Talk
  • Introduction to Transistors Talk

My LeanDog co-worker, Steve Jackson, will be submitting a talk about some awesome load testing & environment architecture that we both worked on for a client that I will co-present. Also, I might be co-presenting a talk with Nick Barendt on Pub/Sub Patterns for IoT.

Of course, any or all of this "participation" in CodeMash is subject to the whims of the Tiki Gods that review the talk submissions.

Wednesday, August 5, 2015

Contextual Electronics... Now with Embedded!

Yeah, so it's been a while... OK, a loooong while since I last posted. So, what have I been up to?
  1. Youngest daughter turned 1 earlier this year, has become significantly more mobile...
  2. A lot of flooding happened in North East Ohio earlier in the year, been doing a lot of landscaping to try & repair things.
  3. I, along with Ronald Sousa, am working with Chris Gammell on the new Embedded curriculum of Contextual Electronics - The online Electronics Apprenticeship.
 This tweet kicked off the whole thing! I'm super excited to be working with Chris & Ron on this endeavor. I have done some embedded programming in the past, but this will take things to a whole new level... the HNL as a former co-worker once put it.

Ron made a great kickoff video about Migrating away from the Arduino IDE if you are interested in learning more about the magic in that environment.