A 555 story.

Today, while doing a birthday present for a soon-to-be electronic engineer friend, I remembered a story from back when I was studying electronics.

We where doing a few montages: 555 timer, constant current source + triangular signal generator and triac switch. At the end, whe where bound to add all that up, and make a lamp dimmer, that used the triangular signal, with a fixed pwm signal from the 555 timer.

The thing tough, is that whe where using a period about six to eight seconds long, so I thought that, in order to show that I had understood the 555 circuit, instead of the triangular signal, I would use the charging and discharging capacitor as voltage source.


Yes, I know that the capacitor charge and discharge is not especially triangular like, but given a long enough period…and if you don’t know that your student is trolling you, it looks triangular-ish enough.


So, to add to the fun, when I presented the paper, instead of explaining the intended relationship between circuits, I said that, given the purpose of the circuit, and the limitations of the human attention span, a simplistic approach using the 555’s capacitor, was the most elegant way to do it.
Also, you could use a constant current source to generate a real triangular signal, but that was overcomplicating.

Would you say that my teacher didn’t like it and made me rewrite the paper? (that was a 20 minute job, so no hard feelings, but I had my laugh).

Trolling teachers to show understanding is so fun!, nowadays I only get to tell one of my bosses that he works like crap, (BAM!, to his face, in front of the main engineer and my massive-angel manager). Their faces where priceless, or so I’m told, as I was too concetrated on the problem at hand, in disregard of who I was talking to.
That’s what happens when I’m 110% sure of something, I just ram against anyone who tries to disagree.


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