Super easy 555 PWM Generator - Never Breadboard Another 555!

PWM square wave generator using a 555 and a 10 pole rotary selector switch.
The 555 is ubiquitous and schematics are readily available online. Seems almost every experiment requires a clock or a PWM signal. Each time I have to go through my junk box to find the components and then breadboard a 555, again. Recently, I salvaged an old rotary switch and figured it could help save a lot of time. I built a standard 555 square wave generator. Then I added a couple diodes and two potentiometers to control the positive and negative duty cycles independently for use as PWM. Then, the magic sauce; instead of adding a single capacitor for a specific range of frequencies.... I attached nine caps to the rotary switch. Viola! Simply turn the dial and you have access to nine separate capacitors from 10nF to 4.7uF. The box is made from scrap metal.