This is the test board I made up for the experimenting with polymer capacitors challenge based around my current amplifier project. I had meant to include this in the first challenge blog, but published the blog without including it, so I will put it in my own blog with a few things that went well and improvements that could be made.
Blog 1 - Using polymer capacitors in the current amplifier
Blog 2 - Test results for polymer capacitors in the current amplifier
The video shows how easy it is for me to remove the amplifier board to changeout the capacitors.
The one thing that has impressed me are the Wago terminal blocks I used for the AC power supply and DC fan supply connections. I have come across spring style terminals in lamp fitting many years ago, but have never really used them for anything else. The apparatus I work on will generally have DIN style screw terminals with a cage clamp, but as I have started to wire up my new garage, I have utilised them some more and their ease of use made me look at alternatives available for my test board.
As can be seen below, these spring style terminals do not cause any damage to the ferrules inserted into them, unlike the standard electrical screw connector block commonly available.
A close up picture shows the screw indentations on the ferrule that has been in the screw terminal block. Multiple tightening and releasing will eventually lead to the ferrule needing to be replaced.
The close up shows the screw indentations and the undamaged red ferrule ,that has been utilised I the Wago terminal block.
The other good think about the Wago blocks is that they have much less exposed metal - giving a safer working environment for testing.
The other thing that has impressed me is Gorilla glue, that I used to hold together the metal bracket for the SMA connectors. I know that there is not much pressure on the plate as I am only unscrewing a couple of SMA connectors, but the joint between the two right angle sections is just on its edges and it has held without any problems. I did rough up the galvanised finish before applying the glue.
A couple of things that have not worked so well.
The red identified SMA lead is a little too close to the metal bracket glued on and makes the SMA connector awkward to disconnect. I have also positioned the complete bracket with all of the connections too close to the amplifier board supports. This doesn't leave much room when unscrewing the red and blue SMA connectors.
I also planned to utilise wing nuts on the 4mm jacks for the amplifier output leads. However, I positioned all of the holes centrally in the bracket and the wing nuts fouled and could not be screwed on, so I resorted to normal hexagon nuts. The use of these though has eventually damaged the 4mm jacks and the metal insert has started to pull out of the plastic holder.
You can see this on the yellow 4mm jack, where the metal section has now pulled through more in comparison to the black jack. Some more Gorilla glue may be in order soon to fix this.