rapide555

Last update: Thu Jun 5 22:25:41 2025

Rapide555 is a board of my RapideXXX series, small boards for quick prototyping, with everything you need around one component. This time, the all famous 555!

Presentation

Principle

Small board, monopurposed or multipurposed if better. For me 555 rhymes with PWM, so that will be the base business case (<- I'm working too much). Then around that I want to be able to hijack that quickly into other fun use cases of the mythic 555: monostable, on-off button etc... I won't fit them all, there's entire books about 555 circuits! Just make sure I have enough pins free for soldering the puppy in other config than PWM.

Points of interrest

Implementation

Bill of materials

555 in DIP format (I like it retro, and 8 pins anyway you're not saving much with the SMD version)

PPTC?

Power regulation?

2 free PCB holes per pin, in case

Solder switch ready to close to immediately get a PWM config

Optional status LED

Schematics

PWM555 (as in Aquarium Lights)

Gives a nice 98% - 8% or less range. Could be made better though.

IC1: 555 in DIP format

R1 and R2: 100 ohm

R3: 470 ohm

D1: Schottky diode

C1: 0.1 uF

Q1: IRFZ44N MOSFET

R6: potentiometer, 1k - 10k

Source code

On GitHub.

Pictures

Links

Helpful sources

Inspiration

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