JK flip-flop racing
Why Electrical Engineering Stack Exchange recommends it
Electronics Stack Exchange users link it as a clear, hands-on demonstration of JK flip-flop race conditions and as the source of a circuit people ask about or cite when it appears to be wrong.
Recommended by 1 people across 1 different months, 2019 to 2023.
What it is
Ben Eater builds the JK flip-flop circuit from his previous video using 74LS-series NOR and AND gates, then shows on the breadboard that it misbehaves. He demonstrates the 'racing' (race-around) condition, where the output keeps toggling while the clock is high.
What people said
Recommends Gunther Schadow · 2020-07 · Electrical Engineering Stack Exchange · on “Is it mandatory to include a pulse detector in order to design an edge-triggered JK Flip Flop using logic gates?”
I'm just at the same problem and find this demonstration perfectly instructive of the issue. Ben Eater: JK flip-flop racing [this video]
Cites matryx · 2019-07 · Electrical Engineering Stack Exchange · on “Which of these is the correct circuit for JK flip-flop”
If you read through the comments for that video, you can find that someone has pointed out that as a mistake (the one from your second diagram). And apparently that has been corrected in his next video [this video]
Cites Omar and Lorraine · 2019-11 · Electrical Engineering Stack Exchange · on “Why does this capacitor shorten the clock pulse?”
I am trying to understand more about electronics. To this end I started studying the Ben Eater videos. Brilliant. But there is something I don't understand about this circuit. Specifically it's to do with the reason why that capacitor will shorten the clock pulse. simulate this circuit [LINK] – Schematic created using CircuitLab [LINK] Link to a video that shows the capacitor [LINK] . You can fast-forward to 3:19 to see it. Another video where he's got the clock pulse up on the oscilloscope [this video] . This may be seen at around 9:21. Why does the voltage after the capacitor slope down like that, and then stay low? It's as though the capacitor's resistance increases to infinity as it charges,
Cites Paa · 2020-04 · Electrical Engineering Stack Exchange · on “JK latch, possible Ben Eater error?”
Is it possible that the schematic shown here [this video] is wrong? [LINK] I would expect something more like that [LINK] ... [LINK] It seems like that he inverted the feedback wires, but I'm quite suspicious because he made the circuit and it works, I'm a bit confused. EDIT: as said in the comments this is not a flip flop, but a latch, sorry for the error.
Critical Math Keeps Me Busy · 2023-09 · Electrical Engineering Stack Exchange · on “Which of these is the correct circuit for JK flip-flop”
@Allen The mistake is much greater than simply that the J and K are swapped. Watch the rest of [this video] beginning at 188s. The circuit has a race condition, and works only intermittently.