Hello guys, I have two questions on you.
I'm working on a bench power supply from an old ATX power supply. I don't have enough money for a proper lab power supply - I know that it won't do miracles, but I just need something to power my experiments. I want to make a power supply with 1x variable output, 2x 12V output, 2x 5V output and 2x 3.3V output + 2x USB connectors for charging. I've added Arduino for measuring voltages, LM317 circuit for the variable 1.25-10.8V line and some thermal sensors for measuring the temperature. This part is done, it works. But here are my two questions:
Every time I read about ATX PSU conversion to bench PSU there is something about a dummy load on the 5V line. But I don't know if I even need it. I've tested my ATX PSU. It outputs stable 12.06V, 5.09V and 3.4V. When I attach some load (9V DC electric motor - no matter which line I use) - it works. Voltage drops only slightly, current is around 1-1,5A - and voltages across all the other lanes are the same. Does it mean that I don't need a dummy load?
I unsoldered the 3.3V sense wire, because I want to have two 3.3V outputs, not just one - I thought that I might solder back two another wires and attach one of them to each 3.3V output line. Will it work? Or it won't get accurate information when I will draw different currents from different outputs? Or it will be better to attach that sense wire only to one output? Or should I keep it removed?
Thanks for your answers