New, just started, project! =) Involving switch-mode power supplies, encoders, buttons, LCD screen, control theory and the Teensy 3.1.
I need a simple power supply, driven from 5V, for quick and easy use when testing stuff. Usually I only have the 5V from the Uno board at hand when using my breadboard, this leads to trouble as soon as you want to test something involving something as regular as a standard OP.
It should have:
*Two variable outputs: 5 15V & -15 -5V. (Not 0V for simplicity.)
*Two fixed 3.3V & 5V.
*CV & CC operation, or at least current limiting.
*Encoder and buttons to set voltages and current of the variable outputs as well as the current of the fixed outputs.
50mV accuracy or so should suffice.
This will also be a learning experience for me. I will try to make my own SMPS-circuit, controlled digitally via the teensy in a closed-loop control system.
Perhaps, when time allows, an function-gen output as-well.
I've been having trouble getting by "big-ass" mosfet, from an old class D amplifier project I'd been working on, working with the 3.3V output from the teensy (gate charge, threshold voltage etc.). Eventually I managed to put together a circuit with a 3.3V to 5V level-shifter + totem-pole-driver to drive the mosfet. This mosfet will not be used in the final design but I will use it for a proof-of-concept breadboard circuit . According to my first simulations I am able to reach around 80% efficiency, which I find fantastic. It's not too close to the commercial ICs but hey, it's 80% efficiency with only a switch, inductor, diode and cap.
After realising the big issue with getting god efficiency when designing your own SMPS I've been looking for controllers and converters to help me out. The result so far has been that there is none that is available to me and fits my needs so I'll have to turn down my current specs a bit, to say around 100mA for the two variable supplies, and do it myself.
I think I'll upload the .asc files from ltspice when I get a working circuit.