Hmmmm, not sure if I should reply to this thread as I don't 'dabble' in electronics, but do it professionally.
I have a couple of spare time projects on the go:
1) An electronic ignition system based around a M0 core ARM processor and an avalanche MOSFET. The aim is to eliminate the shortcomings of the simple Darlington transistor ignition systems and, most importantly, use an ignition coil that has a 10:1 winding ratio between secondary and primary. A home designed spark plug is also part of the equation.
2) A simple processor circuit with 'constant current' drives for white and red LEDs in lamps for my traction engines while simulating the intensity variations of an oil lamp.
Professionally I have at least half a dozen circuits in progress as well as mechanical design and 3D printing, but of course I am not at liberty to say what they are specifically. But I can pick out a few general sub-areas:
1) Isolated power supply 48V to 7.4V, at 2A, with isolated measurement of output voltage and current.
2) Circuit for accurate measurement of low currents, ie, a few nanoamps
3) Digitally controlled power supply from 0 to 10V at 500mA and which will follow a 1kHz control signal – current design uses less than half a square inch of PCB, just as well since there are eight PSUs per PCB
4) Several processor designs using a M4 ARM core processor with RMII interface to WiFi, SDcard, USB2.0, GPS and other interfaces
5) Lots of precision, better than 0.1%, digitally controlled analogue AC drive and sensing circuits
6) Lots of bogstandard switch-mode power supplies
7) And all the PCB layouts for the above – an interesting mix of switch-mode power supplies, digital signals in the tens to hundreds of MHz and precision low level analogue electronics all within an inch or two of each other.
The biggest problem with electronics today is that I can't see the darn components. Everything I do is surface mount and the components just keep getting smaller. That's why I am building 4" scale traction engines, at least I can see the parts.
Regards,
Andrew