In this project, I'll make a small circuit capable of controlling a servo, it is a servo tester made out of a 555 timer IC.

The Proxmark3 PCB 125kHz antenna., GNU GPL version 2, GitHub link. Picture this: It’s the end of the year, and a few hardy souls gather in a hackerspace to enjoy a bit of seasonal food and hang out.

The improved one-BJT current-limiting supply is not much different than the primitive circuit, though its one additional resistor does change the circuit behavior. The improved circuit is shown below.

I recently published a Design Idea (DI) showing some very simple circuits for PWM programming of standard regulator chips, both linear and switching, “Revisited: Three discretes suffice to interface ...