To power a
#microcontroller the author needs a voltage between 3 and 5 V, but only a 48 V battery is available. There are very few ready-made modules or ICs capable of handling such a high DC voltage. So why not design a circuit independently? The first idea was a classic step-down
#converter controlled by a multivibrator as pulse generator. Since the battery voltage is fairly constant, an unregulated version would be sufficient. The voltage could be coarsely adjusted via the duty cycle.