The bipolar NE555 timer IC is widely used in inductorless dc-dc converters, most frequently in doubling and inverting converters. However, another very popular IC, the LM386 audio amplifier, may be a ...

Here is an interesting hobby circuit of a “crank” door bell! The circuit is built around a timer 555 and a musical piezo-buzzer. The circuit works off 9 volt battery supply. One 9volt PP3/6F22 compact ...

We’ll start with my power supply. It’s a 143D two amp bench supply from Southwest Technical Products Corporation [8]. It came as a kit, and I built it around 1968. Although admittedly the caps are ...