The other day I’ve built myself an ESP8266 WiFi dual-relay for standard DIN rails.
Electronics Bottom PCB The bottom PCB is fairly simple, input goes through a polyfuse and a bridge rectifier such that I can power it both from 8VAC-12VAC or 12VDC. And then just a 7805 with protection diodes and a heatsink. At 12V the 7805 dissipates around 0.6W of power which doesn’t sound much, but it gets hot.
Leitz REDYX Fuse Addition
I have an old Leitz REDYX variable AC transformer for 6V and 8V tungsten microscopy lamps. Unfortunately it does not contain a fuse, so in other words if the transformer has an isolation failure it will start smoldering until the main circuit breaker for the room trips. So I figured to improve the safety I should add a fuse. In this case I’ve only fused the primary side, it might be a good idea however to fuse the secondary sides as well. But since I only run tungsten lamps from this there isn’t much of a danger of a prolonged short circuit on the secondary side (not without me noticing anyway).
Apple PowerBook 170
So I recently rescued an Apple PowerBook 170 from ca. 1991. I couldn’t find the power supply, but fortunately the power connector is just a standard DC jack requiring 7.5V - so I removed the (probably broken and internally leaking) NiCd battery.
So I took a DC jack, hooked it up to my lab supply …and bingo! Started up right away! However the mouse ball didn’t worked initially, turns out it was dirty. Anyone still remember those days when you had to clean your mouse wheels from time to time? After cleaning the internal wheel up a little bit the mouse worked as well.
Now powered by Hugo
I decided to switch the content management to Hugo, because my old site was a mess out of custom Perl scripts that generated me the static HTML. Hugo on the other hand does this all for me and in a consistent manner.