This is the second post on my power supply build – also see part I and the Circuitmaker project page. The aim of this project is to design and build a linear bench power supply with adjustable current and voltage and up to 2.5A output from 0-30V.
After building and testing the first version of the board I discovered a couple of issues. Most of the basic functionality worked – the voltage control, digital display, transformer tap select, etc. However, the current limiting never worked properly, there were some noise/oscillation issues and a couple of mechanical problems. So, Rev.1.1 was born which has now been tested and seems to be working nicely.
Continue reading Bench Power Supply Build – Part II
I have finally finished my temperature monitor and logging module, originally designed to monitor beer temperature as it is fermenting (beer, fridge and ambient temperatures). It is an Arduino-based device which measures and displays temperatures from multiple attached temperature probes and logs them to an SD card . This is an old project from last year sometime which has been sitting 95% complete, just waiting on an enclosure and some finishing touches to the code. I posted a separate post about the enclosure design and 3D print, read it here.
Continue reading Temperature Logger
This will be a quick post about the design and 3D printing of a custom enclosure for a temperature logger (see full writeup here) – a project which has been sitting on my table 90% finished for about a year now. I always find the enclosure to be the most time consuming and least interesting part of any project. As such an unfortunately high number of them stall at this final stage. 3D printing a custom enclosure is a much more interesting and attractive alternative to my usual approach of attacking a jiffy box with a drill and hacksaw.
The box needs to hold a board roughly 90x50mm, have a slot for an SD card, 3 temperature probe input connectors, a DC jack power input, a 16×2 character LCD and 3 pushbuttons. The design was all done in Autodesk Fusion (see my previous post) and printed on my Printrbot 3D printer (see my previous post). There were several iterations and test prints along the way to check sizing and tolerances and to test out some different designs. The final design can be found on my Autodesk account here.
Continue reading Designing a 3D printed electronics enclosure
This is the first post on my power supply build. Also see part II and the Circuitmaker project page.
An adjustable bench power supply has been on my list of things to build for quite a while. A linear supply should be relatively simple to design, with the added bonus of being a useful thing to have around. My goals with this project are to design and build a slightly more complex system than I have in the past, to lean to use PCB layout software and to actually get a PCB designed and manufactured. I wanted to design it from scratch, rather than using an adjustable 3 terminal regulator or a controller chip with everything built in – this is supposed to be a learning experience more than anything else.
My requirements are:
- 0-30V adjustable voltage
- 0-2A with current limiting.
- Separate fixed 5V output for powering digital circuits.
Continue reading Bench power supply build – part I