555 timer Easter egg?

What’s in a name? David L. Jones of EEVBlog thinks he’s found an Easter egg in the performance characteristics of the 555 timer chip which reveals the basis of the “555” in its name. Build his circuit (schematic at video 13:25), fire up the scope and see if you agree!

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  1. LOL, guys, that was April 1st joke. Dave is known for these – the last year’s one was also pretty good!

  2. He seemed so enthusiastic, but I kept thinking: Wouldn’t the results change with different external resistors and capacitors? I mean, it wouldn’t always be 5550 Hz or 55.5 kHz, but might be any frequency. I’m not talking about the power supply filter cap that he made a point of removing and reinstalling, but the other primary capacitor that “programs” the time constant of the timer chip.

    Anyway, I guess a really good engineer’s April Fools Day joke makes you think as much as it makes you laugh.

    P.S. The joke would have been even more fun if he had made the noise appear at 555 Hz!

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