I have a device with two possible output pins with max. rating 60V/1A and 12V/100mA that I would like to connect to an ESP8266 (that sends notifications when ON). To keep it simple, I would connect it as a regulated source (3.3V) directly (without transistor or optocoupler) to Vcc and so on so It's not necessary to use another external source. (Maybe I should, as an amateur I'm listening to you.)
Can you please give me a direction how to regulate the source? Linear regulator (as the main part) seems to be inefficient in this case so maybe a switching (buck) regulator? The 60V seems to be high for that and 12V has only 100mA that seems to be low for the ESP (even with a capacitor?) as it needs about ~50-170mA with ~350mA spikes (thats what I have found)? Is there a way how to lower the voltage to rise the current (transformator, inductor or anything? )?
to keep the answer one and clear: How would you regulate/use 60V/1A or 12V/100mA to get ESP's 3.3V/~300mA?