Hey everyone.
It is weird that after many in-active years with my electronics that I managed to jump straight back into it without much problem.
Anyway I (before acquiring my large dual rail PSU) needed a small lowish current variable power supply in order to test and work on my various projects. These things costs a small fortune in the store. So this small project was born.
At first I decided that a simple LM317 could supply more than enough power for the type of projects I was looking to work on. Well it is but that is for another post.
I drew up the schematic in Eagle which is where I do most of my design work.
I eventually assembled the Regulator control board on my breadboard and low and behold she worked beautifully. The only problem was at full load the LM317 got pretty hot. Well to cut a long story short The LM317 and the 7805 that powers the logic board have been mounted to a heatsink which I salvaged from a none working UPS. They do get warm now but not hot per say.
This Vero board with Heatsinked LM317 can be seen below:
The other veroboard on the top left of the case is the 5V supply for the logics as well as the voltage and current sensing circuit which brings the signal to within spec for the ATMEGA to be able to read on its analogue inputs.
I first built a fully functional unit with the ATMEL on a breadboard however I did not like the build even though it worked well and decided to use an okd serial Arduino board and removed the female pin headers and replaced with male pin headers. I then programmed the ATMEGA328-P on one of my other Arduino’s and placed it into circuit.
All alignment of volts and amps is done via the 3 buttons on the back of the case which puts you into setup mode and allows you to fine tune. No variable resistors or such to fiddle with.
FIRST VERSION MOUNTED TO VEROBOARD:
SECOND UPGRADED VERSION WITH OLD SERIAL ARDUINO:
In the above and below images I am aligning and setting the unit to within spec.
Close enough for me. I also verified and tuned again using my Fluke DMM as well. Hell for what I need it for its more than within spec.
Well this is the end result.
She is back on her spot on the bench and raring to go. Alongside her big sister…. :-P
No comments:
Post a Comment