An astable 555 multivibrator circuit, where the timing characteristics are determined by the interplay of an inductor, resistor, and diode.

Whenever I use the 555 timer, it seems that the output polarity is invariably incorrect, and the way the 555 functions, it normally cannot generate a duty cycle of less than 50% — 90% yes, 10% NO!

There is many a comment on these here pages along the lines of “Why did you use a microcontroller, when you could just have easily used a 555 timer!” And, yes, we sometimes agree with t… ...