Gigabit Power Over Ethernet Injectors Project Built

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While going through my electronic project folders, I came across one of my past project, the gigabit power over ethernet (PoE) injector that started some time in May 2012. The motivation for this project was when I wanted to add a second WiFi access point in order to expand wireless coverage for the whole house.
There were limitations or requirements for the task, firstly was the location only had an RJ45 termination nearby and the nearest power socket was at least 5 meters away. Secondly the access point that I would be using is an 802.11n rated 450 mbps transfer speed. In order to fully utilized it, the uplink would have to be gigabit ethernet.


High Side Switch Using N Channel Mosfet

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I've built up a prototype board for using N channel mosfet as high side switch. Usually, P channel mosfets were used in such application. However, they have higher RDS(on) resistance as compared to N mos and they also cost slightly more. Another downside of using N channel as high side switch is that it requires a form of bootstrapping its Gate voltage as it requires >Vs + Vth in order to fully turn on.


4 Channel Electronic DC Load Project

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This is a backlog entry for my 4 channel electronic DC load project build which started on 26th December 2012 and completed on 27th May 2015. This build is the 3rd iteration of electronic load I've build so far.

Completed 4ch dc load

Adapting Thermalright XP90 HSF to LGA1155 board

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So I had a Thermalright XP90 lying around which I thought it would be wasteful being kept in the storage. The HSF fits natively onto a stock PGA478 retention bracket. I've decided to try to to adapt it into a LGA1155 board.
A quick search on Google shows that the mounting holes on the are close to one another. I would just need to split the PGA478 retention bracket apart on its width.

LGA1156 dimensions

Pico PSU quick modification

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These little ATX power supplies could be bought off from Ebay cheaply. Its build quality wasn't that bad. It works fine on my old Intel Core2 system. However, I don't like the fact that it uses a single AWG20 wire to on the 12V-ATX connector. There's no way it could safely powered a 65w or 5 amps CPU.