Add VoltMeister 100 Part 2

content/posts/2014-11-24-voltmeister-100-atx-bench-power-supply-part-1.md

@@ -26,7 +26,7 @@ This is Part 1 of a two part write-up of how I designed and built my first bench
 power supply.
 
  * [Part 1 - Design, schematic and PCB](https://ariejan.net/2014/11/24/voltmeister-100-atx-bench-power-supply-part-1)
- * Part 2 - Enclosure and finished build - _coming soon_
+ * [Part 2 - Enclosure and finished build](https://ariejan.net/2014/11/26/voltmeister-100-atx-bench-power-supply-part-2)
 
 ## The ATX Power Supply
 

content/posts/2014-11-26-voltmeister-100-atx-bench-power-supply-part-2.md

@@ -0,0 +1,104 @@
+---
+title: "VoltMeister 100: Bench Power Supply - Part 2"
+created_at: 2014-11-26
+kind: article
+tags:
+  - electronics
+  - voltmeister
+  - power supply
+summary: |
+  In Part 1 of this series I discussed how an ATX power supply can be used
+  to create a poor man's bench power supply. In Part 2 I'll show you how
+  I managed to fit the ATX power supply, my control board and everything
+  else neatly into a single box.
+---
+In [Part 1](https://ariejan.net/2014/11/24/voltmeister-100-atx-bench-power-supply-part-1/) of
+this article I've discussed the design and PCB layout for my _VoltMeister 100_ project. 
+I've converted an ATX power supply to a safe-to-use bench power supply. Although not ideal 
+for anything serious, it's a great way to actually get started and complete a project.
+
+This is Part 2 of a two part write-up of how I designed and built my first bench
+power supply.
+
+ * [Part 1 - Design, schematic and PCB](https://ariejan.net/2014/11/24/voltmeister-100-atx-bench-power-supply-part-1)
+ * [Part 2 - Enclosure and finished build](https://ariejan.net/2014/11/26/voltmeister-100-atx-bench-power-supply-part-2)
+
+## The enclosure
+
+I think that in a professional design process there is some tension between the PCBs you design, the
+components you use and the enclosure you need to all fit it in. I tried to be smart and opted to buy a 
+'universal enclosure' that would fit my ATX power supply and leave some room for a small PCB.
+
+Because of the dimensions of the ATX power supply (roughly 140x50x80mm), I needed something that would fit that.
+Note that most dimenstions specified when shopping for enclosures are _outside_ dimensions.
+
+In the end I opted for a nice Hammond enclosure, large enough to fit my power supply snugly and not 
+too expensive. It even has nice aluminium front and back panels. For those wondering, it's 
+the [1598ESGY](http://octopart.com/1598esgy-hammond-46506) from Hammond.
+
+![](/img/hammond-enclosure.jpg "Hammond Universal Enclosure")]
+
+Another thing I learned is to take a detailed look at the specification drawings.
+
+![](/img/hammond-inside.png "Inside the enclosure")]
+
+Notice the two supports circled in red? Yeah, those are used to screw the top and bottom parts of
+the enclosure together. And guess what, my ATX power supply does _not_ fit between those
+two supports and is now protruding about 10mm from the back. Booh!
+
+This is really a problem. I don't want to have an ATX power supply hanging out of the back. 
+
+At first I thought of just buying a larger case, but I would not be that easily defeated.
+
+Because I'm curious by nature, I opened up my ATX power supply to see what's inside and
+remove some of the cables I would not need.
+
+The PCB for the ATX supply is pretty tightly packed, but I noticed that transformer on the side was
+not mounted on the PCB. There was a nice cutout on the PCB to allow room for the transformer.
+
+Putting one and one together I decided to remove the ATX enclosure and see if I could fit 
+the PCB in my small Hammond case. The transformer could be moved just a bit so it would
+not interfer with the support inside the case.
+
+This worked brilliantly. All I had to do was make cutouts for the powercord and 120/230V 
+selector.
+
+The only reason I did this is because there is a clear separation between the high
+voltage parts of the supply and the control (for the fan, I presume). Because the 
+orientation was just right, it would also shield my own PCB nicely.
+
+## The build
+
+Here you can see the inside of my bench power supply.
+
+![](/img/case-inside.jpg "Inside the case")
+
+The bottom half is filled with the ATX PCB. You can see the ground wire floating around, 
+this has been connected properly tot he front and back panels.
+
+The transformer is leaving a bit of a gap and has been placed just on the other
+side of the support. 
+
+On the top you can see my PCB with the ATX connector attached to it and wires going
+out to the LEDs, the power switch and the different output voltages.
+
+## The result
+
+And, this is the end result. Suffice it to say that my precision drilling skills need 
+some more love. But other than that, I'm quite happy with how it turned out. It's my
+first project, after all.
+
+![](/img/voltmeister-100.jpg "VoltMeister 100 in all it's glory")
+
+## Conclusion
+
+Building an ATX-based bench power supply like this is nice. If you need
+a stable and reliable power supply, you're probably better off buying a cheap
+linear power supply online for like € 50. 
+
+I did this project to learn something. And I did. I learned how to SMD solder components,
+I learned what to look out for when selecting an enclosure for your project. I also learned
+about ATX power supplies and how you don't want to mess with them. These units handle
+pretty beefy currents. If you don't know what you're doing you could end up hurting yourself.
+
+What's next? The VoltMeister 200, of course!