I had built a power adapter for my in-laws earlier using a white box to power a wifi router and DSL modem. It did work well at that time, but it eventually got damaged due to melting of the box by the transformers getting hot. While I could have fixed it by replacing the transformer, this time I wanted to build a better power brick. I wanted to let go the heavy / ugly transformers and instead use switching power supplies I scavenged from power adapters lying around in my junk box. I also wanted to make it look cool this time so that won’t sit behind the computer table. So I thought about using a transparent (Acrylic) casing for it with guts visible. The final product looked good and also pleased my in-laws as it looked cool.
Here’s how I switched from ugly box to a transparent adapter.
The old box was meant to supply power to two devices.
1. A DSL Modem running with a 12V power supply.
2. A Wifi Router running with a 5V power supply.
Both devices had their own power adapters but they had gone dead. As there was already a shortage of power sockets near the computer table ( well, most of us face this problem ) I thought of putting everything in one box and also adding a socket it for extra plug. This way, it can take care of three devices with one socket. Built some three years back, I was happy with the results, as I shoved all the parts in one nice box.
But over the time, the white box gave away to the hot transformer. The box melted and it caused a short circuit killing the 12V supply. I tested and found that the transformer was dead. So, I thought of replacing it. Then it occurred to me to build a better one this time. Use switching supplies instead of transformers. As I scavenged my junk box, I found everything I wanted.
Building the Box – Raw material : I had 2 hours to finish this small project, as without the adapters the internet was down for my in-laws without power supply for DSL modem & wifi. I took the dead white box and drove back home. I searched and found following items that I could put together for the new supply.
1) A Transparent box that an iPod Nano came in, as enclosure. I checked and found that it had enough room to hold two power supplies separated by enough space to avoid short circuit (again). Apple builds stuff with high quality material, so I believe the box will be pretty sturdy.
2) Few small sheets of PVC. to be used for building interiors.
No screwing, only using hot glue for this project to finish it fast.
3) A small night-lamp. To give it a glow. ( Who doesn’t like a glow ). It will also serve as the prongs for the power brick. I tested and found the prongs were designed well to fit snugly in most wall sockets.
P.S. In India, the wall sockets/ plugs come in variety of standards. I mean most are similar but I hate the minor differences that causes plugs/ adapters to fall off very often. So its got great value if a plug fits the sockets well.
4 ) Power supplies. I cracked open two working power adapters that were lying around; were earlier used in a 8 port switch & a PPOE router that I don’t use anymore. I confirmed that the current ratings of 1000 mA at 12V & 5V respectively were good enough. I kept the cables with plugs that will be later used.
Building the box – Assembly : After collecting everything, I got started with a hot glue gun & soldering Iron. I know, you may hate Glue, but I had planned to finish it in one hour. I also was fascinated by idea of giving it a hand made look. Besides, nothing is as easy as just using Glue to put things together for electronics projects.
I measured the box on how to put things together. As I wanted the guts to be visible, I decided to mount them side by side with components showing outside. drill holes in the box for the cables and mount the prongs directly the box. It will make it like a standard power brick that can be directly plugged in.
I cut the sheets to form two cavities for both the PCB’s. Glued them inside the box. I tried to avoid gluing the outside transparent areas as much as possible but couldn’t do it well. I believe that the glue is a creature with its own brain and will. it will always stick to places where you don’t want to.
Anyway, it was not too bad. I drilled holes for the plug cables. Inserted the wires from the holes & then soldered them on the PCB’s outputs making sure that polarity is correct.
Then I disassembled the night lamp. it was secured by few Philips screws. it had three parts; prongs with circuit, a translucent body and top cover. I carefully soldered two pieces of wires to the direct 220V power on the PCB. Cut holes on the box so that the box can be sandwiched between the two parts of night lamp.
I drilled a hole on the back plate of night lamp to take the wire out of it. These wires were then routed from the transparent cover of the box to be eventually supply 220V to the two power supply circuits.
After doing so, I put the parts back together and tightened the screws.
This is what the end result looked like. The cover can be put back on the main box.
Final Assembly : I was happy to get this far in first hour. I wished to rush from here, but took time to make sure the assembly was correct and there was no loose connections/ soldering.
As you can see, the cover was put back, the wires coming from night lamp were soldered to the two power supplies. The cables with plugs come out of holes in the box. I added some more glue near the holes to hold the wires and not stress the circuit solder pads. I tested everything with a multi-meter and it looked ready to go.
Finished Product Comparison : The finished box looked nice and worked well. After testing the Voltage on the two plugs, I marked the plugs with 12V & 5V so that they do not get plugged to wrong devices.
Here is a comparison of the old and new power supply.
Thanks for reading…