Hello everyone, newbie here. Recently I've taken some interest in small electronics as a hobby and of course one of the first things I've found is the EEV YT channel and this forum. I've always tinkered with electronics but only with the most basic stuff. I would change a capacitor or something obviously blown, make a new charger from an old one adding a voltage divider with some resistors and stuff. Nothing sensational, I just liked spending some time with this stuff on a weekend.
However recently my interest has peaked and I'm set on educating myself a bit more about basic electricity and electronics and start experimenting with my own small circuits projects, arduinos and so on. Hopefully, one day my very own Nixie clock.
As the title suggest, I've decided to create myself a bench power supply so I don't have to rework old power adapters I have laying around constantly and jump start my hobby, hopefully not literally. My lack of knowledge however ran me in to some problems that I hope to get advice for from you guys.
First off, before I proceed with my questions, here is a link to a "schematic" so to speak of how I imagine the PSU will be wired and all the parts I intend to use.
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Basic plan of the PSU •
Boost/Buck Converter •
Digital Volt/Ammeter for front panel •
Potentiometer to for the front panel with which I will replaces the ones on the converter •
Possible output on/off button Problem 1 : The PSU I intend to use. Unfortunately I've removed all the labels from it because I used it in an acrylic PC build and I didn't want any not even dreaming of using it for what am I about to now. All I know is, it's an old, very decent Fortron 350W PSU with Passive PFC. However I have no knowledge of the current on the different lines of the PSU and I've scoured the internet to find anything more but without a model number it looks like a mission impossible. Will this prove a problem since I'm using it only to power small circuits and the converter is limited to 3A, which I doubt will ever use? Also, will the passive PFC be a problem?
Problem 2 : As I hope it can be seen from the "schematic" I'm not set on how to wire it properly. I will mainly use the 20 pin connector and isolate the rest without cutting them off completely, in the events that I decide to add more non-variable outlets to the front. I've seen DYI supplies that use only one live wire+gnd and I've seen some that connect all the free live wires with same voltage in one. For example, the 12V rail from the 20pin and the 2 from the 4pin. Which is the better solution?
Problem 3 : I want to add a neat button to the front panel that will cut off the power to the banana plugs so I can, for example, cut off the power, set the exact voltage and then put power on. I however lack the knowledge how to pick a suitable button that will do the job and
possibly have an LED indication working. Should I just pick a button as the one I linked with LED rated for 24V, will this just result in a dimmer light while the voltage is set to something lower, for example 3-5V?
Problem 4 : PSU's Ground wire. I intend to remove the old PSU case and use an acrylic-based material to create a new case for the bench PSU. The PSU circuit + the Passive PFC coil and the cooling in the back, the rest on the front panel. However, I have no idea where to connect the ground wire in this situation that would be otherwise connected to the metal case of the PSU. If it matters, I live in an old "USSR" era apartment building that has only 2 wire 220V installation. All the wall sockets are connected to only 2 wires in the main with a bridge between "earth" and "neutral".
I apologize that I came straight in as a new user with this wall of text asking for so much information, and I will greatly appreciate any information provided.