We are giving away some Sparky the Blue Smoke Monster pins in the Adafruit Discord chat! All you need to do is post your wonderful mistakes in the #showandtell channel and we’ll be reviewing them every week or so and randomly picking one! If you’ve won, we’ll message you on Discord so we can send you one!
“I was trying to figure out why this 3-way adapter produced half-wave rectified DC in opposite polarities on the “low” and “medium” setting when my scope ground touched one of the wires and let the smoke out. The blown component appears to be a “quadrac” (combined diac and triac in a single package) in an old TO-105 case. The circuit seems to just put a diode in a series for “low” and a diode going the other way with a non-adjustable triac dimmer in parallel for “medium”.”