I have been working on this for the past couple of months, as a way to learn electronics design but also mostly because most powerbox connectors are not secure.
Sure, you can buy great powerboxes out there but like all the accessories we love they all use those 2.5mm barrel connectors. As I was building my observatory I wanted something secure that would not disconnect with a slew. A few years ago I got so frustrated with my EQ6 power connector and flimsy serial port that I removed the plate and replaced both with Gx12 aviation connectors. I never again had an insecure connection. So of course when shopping for my new power distribution box I wanted something similar. I could have bought a commercial one and added a 3d printed case around it with my own connectors but I thought "how hard can it be to build one from scratch?" after all I had already built several Arduino projects.
- cheap (well at least not as expensive as those awesome 650$ power boxes)
- gx12 connectors
- plenty of ports
- switchable ports, PWM ports, measure power draw on each port.
- open source
And here is the result:
- all-in I spent about 300$ to get 4 boards built ( minimum order was 2 boards for each prototype ), it would cost about 120$ to have one built from my files.
- 2 always-on up to 10Amps ports
- 8 on/off ports 6.5A each
- 6 12V
- 1 5v 5A
- 1 USB 3A
- or any other combination you want out of those 8 12v ports
- 4 PWM ports 6.5A each
- 1 expansion port for an i2c sensor (temperature and humidity) because why not?
Note that my power box does not have downstream USB ports. I wanted them but it turns out that designing a big reliable USB3.1+ hub is really hard and the 'cheap' would have flown out the window with the number of iterations it would have required a non pro designer like me to get it right. So I'll be buying an industrial USB hub to go with it.
If you want to build one or even better: make it better and contribute back here is where you will find everything you need
I included the Arduino code, ASCOM drivers, 3d print STLs and source, all the PCB build files, and am working on Indi drivers.