I was looking for a bench PSU, but was surprised by the prices of these boxes, and also because I'm a Arduino freak (even if beginner) I decided to build my own.
In order to overcome the missing current limitation, I've build a current limiter for the three voltages (3.3V, 5V and 12V) with MAX890L (for 3.3V and 5V) and UCC2915DP (for the 12V) Current Limited High Side Switches. These are Switches which are switching off, if a programmable current is reached or exceeded. All this driven by a ATmega328 programmed with Arduino, what else 8)?
All this integrated in the PSU, with LCD screen showing the limitation for the 3 voltages, and the actual current.
It's working correctly, only problem is that I have probably un unstable tension in my circuit, so the current measurement is not really acurate, but for what I need (eliminating the risk of smoke) it's fine. One day, when I do not have other projects running, I will refine it, but for the time being it's fine for me.
If somebody is interessted, I can post the circuit, code of the PSU.
I attached a photo of it (the led's are "dimmed" with tape for the photo only)
Cheers
Jens
