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Fan Controller

Fan Controller Project

Recently I had the problem some expensive components did overheat in my server rack. The ventilation was not optimal and I had to install additional fans. Because this rack is in my office and I like a quiet working place, the ventilation had to be as quiet as possible.

First I thought about buying a off-the-shelf product, but then I realised: If this controller does not work as I expect and the fans will spin too fast/loud, this will drive me crazy over time. So I decided to build a own fan controller. A very simple one, where I can write own code and tweak it until it runs as I like.

On the project page I describe how to build this particular controller. It is not meant you really reproduce this same controller exactly as shown, but maybe understand some basic principles to build your own controller.

Continue reading on the project page!

Final Outmoded Sequencer

Outmoded Sequencer Part 2 Ready

I just finished part 2 of the project description for the Outmoded Sequencer. In this second part I describe the steps from the prototype to the final device. I copied the preface from the page after this link .

Outmoded Sequencer Part 2

(Preface from the project page)

Building the Outmoded Sequencer was a really interesting project where I learned a lot. It was the first project with a custom designed PCB. Usually I just solder everything onto stripe boards, because I only produce one single device. The complexity of this device with the matrix forced me to design a proper PCB, soldering everything on a stripe board is feasible but requires more space and a different approach for the matrix.

Not everything turned out as well as expected. First there was the idea with the matrix using steel balls as switches: Even with the magnets generating a certain force to the pads, the steel balls do not connect as reliable as I would like they do. As you can see in the demonstration video, it is still possible to have a lot of fun playing with the sequencer – however better connections would make the experience even better.

Should you build your work Outmoded Sequencer? Yes, absolutely! But you should definitely use a different approach for the matrix. Best first only experiment with the matrix part until you have a working solution there before you add the other parts around.

Should you use the provided PCBs? No, better design your own board especially implement the matrix in a different way.

Should you use the circuit design as provided? Yes, definitely! The design is, in my opinion, a very good start and should give you a reliable and working device with minimal effort. Keep in mind: This is a minimal design and there and many ways how to improve certain aspects of the circuit. So feel free to address the problems if you have components left, to spend on this project.

Continue on the project page



Soldering for Show

This article is about soldering for show. While usually you solder electronic components to make the best possible connection and keep everything working, this is just to make a great visual result. If you want to take photos from your projects or would like to impress a customer with a nice looking prototype, you have to solder with more care to the detail.

In the next sections I will describe a few things which are worth to think about, using Boldport Project #4 as an example. If you have any questions or suggestions, feel free to add a comments to this article. Also feel free to ask about any other technique I use, about which you would like to see another article.


To get great results you need the right tools.


First, you really need a good soldering station. The brand does not matter, but the performance does. The solder iron should actually transfer the required heat to the solder joint and this in a very consistent and reliable way. For this reason, the temperature sensor should be as close to the tip as possible. I personally use products from the Weller WT Series.

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Boldport Tap Second Try

Boldport Tap — Second Try

If you already saw the soldering video, here two photos of the result.

To get this result, I was inspired by the way Saar from Boldport was soldering his own projects, I adapted his technique.

  • After initial soldering, I flush cut carefully the wire as close as possible to the board. Cutting off any solder with the wire to make it flat.
  • Next I add more solder to the point  until it forms a small round dome.
  • On the component side I add solder if necessary to fill the hole and make a smooth transition from the hole to the wire.

For this photos I use solder with lead – this is a huge exception. It is the only way to get this shiny domes. Normally I work with lead free components and solder according to ROHS.

Final Outmoded Sequencer

Outmoded Sequencer Live Demo Video

Today I made a short live demo of the Outmoded Sequencer. I just added briefly some audio effects at the end of the video, so you can hear the real sound of the device. Adding effects is a really great way to turn the beep sounds in interesting music.

You can also see the connection problems sometimes happen. A short push on the steel ball solves this problem usually.

Let me know what in think in the comments. Next I will finish the second part of the guide, where I explain how everything was built.

Final Outmoded Sequencer

Outmoded Sequencer Finished!

Hurray! I just finished the final Outmoded Sequencer device. The tuning of all frequencies was way faster than I expected, because I used a new method. Have a look at the following photo gallery before I tell you some details.

You can see the device is build like a control desk, with the PCB a little bit at an angle. The left knob on the top controls the speed of the sequencer and the right one the volume.

A did a few tests already and the idea with the steel balls is working, but not great – just ok. So sometimes they do not connect and you have to move them a little bit until they make contact again. Most of the positions are working always without problems.

It is a great fun to play with the device, changing the pattern while the melody is playing. Now everything is finished, I also can move two steel balls at a time which can create interesting variations.

Next I will do a detailed video, where I demonstrate the final Outmoded Sequencer. It should give you a better impression of the device in action. I will also setup a complete filter chain, so you can experience how easy you can use the sound of the sequencer as input to do various interesting effects.

I will also add the second part of the project page, where I explain some of the details about the magnet matrix and how the whole thing is built.

There are seven absolutely perfect PCBs left, so I think about to give them away if someone is interested into building the project. But be aware, this is no kit, just the plain PCB. You also have to use the exact same components as I did – or at least ones which perfectly fit into the holes. All components should be available to buy at various stores, and I will provide the exact part numbers.

Assembled Outmoded Sequencer PCB

Video: Assembling Final Outmoded Sequencer PCB

Here a short update on the progress with the final Outmoded Sequencer project. I did the whole assembly of the final PCB and connected everything. You can see part of the soldering process in the following video:

I accidentally cut a route on the bottom of the PCB, so I had to fix this with a short wire. It is not visible on the final device. The magnet matrix mentioned in a previous post is already securely fastened to the bottom and holds the steel balls in place.

There are only the final adjustments of the frequencies left to do. I have to tune each tone and add the last four missing resistors.

PCBite Mount

PCBite Arrived

I recently ordered a set of “PCBite”. These are special PCB holder as shown in the images in this post. To solder components into PCB I sometimes used one of this many “helping hands” products with two clamps, but they are no real use in most cases.

PCBite seems to solve some of the problems very well. You get a metal plate with a mirror finish and four of this cylinders which have a very strong magnet in the base. The middle part of the cylinder with the grip on is can be moved down and the PCB fastened that way. It is very solid and two would be enough to hold the PCB easily.

PCBite Closeup

The mirror finish makes the bottom side of the PCB easily visible so you can solder on the top side and keep the component in view.

PCBite Mount

The shown PCB is from my Outmoded Sequencer project.

You can get you own set for $79 here, this includes free shipping. The quality of this PCB holder is outstanding. If you look at the close up photo, you see the perfection how this tool was made. I can really recommend this PCB holder.

Currently I am working on the final assembly of the Outmoded Sequencer, it looks very promising. There will soon be an update with all details about the final device.


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