Firstly, you should read 7400 Contest Pt. 1 first. Or at least skim over it or something.
Anyway, the point of that story was that we didn’t finish our contest entry in time.
So we moved on to plan B.
So for our plan B project, we decided to turn a “heat generator”. That’s right. We just abuse a poor little 7400 series chip (we specifically used a 74hc74 D-type Flip-Flop), until it heated up a lot… and eventually spewed out its magic smoke.
Here’s how we hooked the poor thing up:
We originally tried this with 5V, but it barely pulled 120mA, a meager 0.6W, rising only a little above room temperature. So we tried it with 12V. The results were very nice; at 12V, it used a whopping 1.0A of current, a full on 12W of power being dissipated by a defenseless 7400 chip. This got the temperature of the chip up over 350 degrees Fahrenheit.
Here’s a video of the endeavor:
Unfortunately, we cut the camera right before it got interesting. There was a pop, then the chip started smoking. By the time we got the camera back out, most of the smoke was gone, but we did get a little bit.
All in all, we abused a 7400 chip, generated some heat with it, and left a nice burnt spot on my breadboard as a permanent reminder of the chip that died there.