Power supplies for modern MCU Geiger counters

I am going to build a nice linear PSU for small electronics. I just want a simple and reliable solution for 5V and 12V at 1 amp each. I have all the parts, it's just a matter of digging them out and having some time. I can't be bothered fannying about with crappy SMPs and making filters and things to make good of that which is essentially, bad. And will probably only last 3-5 years before it go pop. I had one go up in smoke a few weeks ago when trying different power supplies. It was plugged in, working, and after a few minutes I could smell it, and then I saw a bubble appearing on the case. It was one of the two(?) 400v smoothing caps had gone dry, heated up and melted the plastic on the inside. I think it carried on working as there was another smoothing cap on the mains side. I don't like cheap SMPs. Never really have done, but certainly don't now. There are some good SMPs though, but they are expensive and usually too big for small electronics. By Big, I mean I don't need 5V at 20A for running a couple of Geiger counters. One amp is enough.

     

 

I was going to throw a linear PSU together a couple of weekends ago, but the transformer I was going to use is too high a voltage so when rectified and smoothed it resulted in about 29vdc. That's too high for my liking to go into a 7805 and a 7812 and would just cause unnecessary heat. I have a bunch of old transformers in the workshop, but the workshop is like a crashed spaceship at the moment, so getting to things is a matter of moving lots of other things. Its a bit like one of those slide puzzles where you only have one square empty. It's a pain. I need more room!   My plans are set on a linear. Quite basic, just the transformer, bridge rectifier, decent smoothing cap, 2500uF - 3500uF should be nice for a couple of amps at 50HZ ripple. So then that right into a 7805 and a 7812 with some small ceramics to remove any small noise around the regulators. And that is about it. I will get around to it soon, after I have finished being so busy....