A little while ago, I posted about using surface mount stencils for the first time on a new project. I’ve been able to get a couple of the units completed, and with some help from a friend with milling the front panel of the case, the units are looking really nice.

This is a PDU based on my earlier design, but modified to better support PoE (Power over Ethernet) devices. The ports are designed as a passthrough, so one port will connect to your switch, the other will connect to the device and receive power. It’s designed to support gigabit connectivity, and handle PoE+ loads.

This new revision makes the project much more valuable for the HamWAN project on our remote sites, where all of our equipment is PoE.

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Cheap Wall Rack

After putting together the ESD protection bar for my PoE devices, I decided that I wanted to reduce the number of ethernet runs I had strung across the garage, so I took some scrap bits of lumber, and made a small, wall mount rack, to put a switch, and my PoE PDU into.

I also took the opportunity to change the uplink to the switch to fiber, to further electrically isolate my outdoor PoE devices from my main server cabinet and network gear.

As an additional bonus, now I can remotely power cycle any of the PoE devices via the PDU in case of an issue.

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2017 Balloon Launch

This last weekend I went over with the class from UW and helped out with the annual high altitude balloon launch. I flew a position tracking payload, as well as a camera that got some pretty nice photos. Check out more on the project page here: 2017 Launch

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Basic ESD Protection

A recent thunderstorm that came through the area reminded me that I needed to work on some improvements to my surge suppression systems. I have a number of outdoor ethernet devices like security cameras with rather long runs of cable outside, and I’d hate to have a surge come through and damage my main switch.

There are a number of options in terms of ethernet surge supression, and I found a name brand at a cheap price in the Ubiquiti devices. Amazon had them to me a couple days later, and I mounted them onto a 1″ square aluminum tube. The tube is then grounded to a rod outside. The whole thing is mounted in my garage right where the ethernet runs enter the house.

It’s a simple setup that didn’t take long to put together, and adds a little peace of mind for the next time a thunderstorm rolls through.

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Surface Mount Stencils

I’ve been working on a project recently that calls for a pretty sizable board, with a fair number of parts on it (4″ x 10″ board size).

Traditionally when I’ve assembled these boards, I’ve either used wire solder and soldered parts on by hand, or more recently, been using a syringe with solder paste, placing all the parts on, and then placing the board in a toaster oven to reflow all the parts at once.

For a board this large though, either prospect was going to be pretty tedious, on top of placing the components to begin with, so I decided that I was going to try using a solder paste stencil this time.

A stencil is simply a sheet, usually of stainless steel or mylar plastic, with precisely cut holes in it where you want the solder paste to go. You squeegee the paste over the top, and it deposits just the right amount, right where you need it.

I got this stencil from OSH Stencils, and it was pretty inexpensive considering again that this is a large board.

The critical thing about it is getting it lined up properly with the board itself. Laying down just the right amount of paste in the wrong spot doesn’t help any, so the pcb, some framing supports, and the stencil were all taped down to prevent any movement.

After placing all the parts and reflowing, I had a perfectly soldered board.

The through hole parts still have to be soldered on manually though. No wave soldering for me yet…

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