(Project) Ultimate Geeky Desk Sockets
I finally got a new desk and decided i didn’t want to keep bending down to plug stuff into my computer nor did i want the computer on show.
I wanted a few more functions than just a desk USB Hub.
Looking on the net i came across this youtube video . This was the type of thing i was looking for but it had far too many functions and too large.
I decided to list the things i would like:
1) USB Hub (powered)
2) SD card reader
3) Basic adjustable psu
4) Mains socket
I decided rather than making something scratch i would see if there was anything available i could just modify to fit all my criteria.
After doing a bit of research i came across desk mounted sockets for office etc. They simply clamp on to the desk and have a mains and Ethernet sockets and being a grid system, this make it easy to customize . Also the aluminum case may be an ideal heat-sink for the variable psu.
New these seem very expensive but on eBay i was able to get one for £15 making the project worth doing.
I started by removing one of the mains and Ethernet sockets as i only needed one of each and this would give me room for extra stuff i wanted to add.
I designed and 3d printed my own face-plates as i couldn’t find any of the correct type as they were not the standard 50mm euro modules that just clip in these were odd size and only slide in a channel. As much work as it sounded it was nice not have to cut holes out and also allowed proper screw mountings ie led meter.
Sd Card Reader:
I bought a USB Stick SD reader and basically glue it on to a 3d printed faceplate and then USB plug was removed and hardwired into one of sockets on the USB hub.
Two sockets were mounted to a custom 3d printed grid plate mentioned earlier. The main USB hub PCB was hidden at the rear this also allowed access to a fourth usb port. The 5v power for the USB ports is supplied from external supply allowing USB charging when computer is switched off.
This is not designed to replace my bench power supply but just provide a quick simple supply that wont take up must desk space etc.
A LM317 based PCB (on ebay as fan speed controller) is used to vary the Dc output. The Lm317 ic is screwed to the aluminum chassis to sink the heat.
This is a very simple supply hence no short circuit protection or current regulation . A cheap eBay Panel meter Display the output voltage behind some tinted Acrylic. Again the components were mounted to a custom 3d printed plate.
An old external hard psu is used for +5v for USB sockets and +12v for the variable supply. The AC for this psu is connected in place of one of the original mains sockets reusing its fuse and mains switch. At the rear of the unit a IEC (kettle) lead comes out that connects to External 12v/5v psu. The DC Enters back in on a 4pin DIN connector. Although it would been nice having a self contained unit but this simply allows for easy upgrade of the psu plus it wouldn’t all fit haha.
Two things caught me out…
When removing the usb sockets from the usb hub it stopped working even though being so careful desoldering them . After head scratching and use of bad words i found the hub PCB used the usb sockets sheild to bridge the ground plane so simply just added a few link wires in. Not being a pcb designer but is it bad practice to bridge tracks with connector shells ?
I forgot the tag of the Lm317 voltage regulator IC is connected to its output and when mounting it directly to the earthed aluminum case shorted it out. After relising the errors of my ways i replaced the lm317 and mounted it with isolating pad and plastic washer.
This a cool project and has made life easier plugging in stuff in at desk level whilst keeping the area looking tidy. The single power switch makes it really useful when leaving in a rush and ensuring everything is powered off.
*For anyone planning a similar Project take extra care when working with mains power and seek professional advice if unsure !