NPN high-edge flipflop

Question

I'm looking for a design of an NPN flip-flop that reverses its output when the input is brought high. I'm looking to use the 2N2222 for this purpose.

"that reverses its output when the input is brought high." That is not how a flipflop works. — AnalogKid, Jun 18 '22 at 02:23
Here's a discussion where the issue is about bringing the input low instead of high. Perhaps this will help. (An inverter would be an obvious adaptation.) — jonk, Jun 18 '22 at 03:30

score 1 · Answer 1 · answered Jun 18 '22 at 02:35

Here is a divide-by-10 counter circuit I designed for fun on a steamy August evening about 20 years ago. Might give you some ideas. I used fourteen 2N4401s but any jellybean NPN transistors with similar hFE should work. I built it as well as simulating it, and it worked fine. It's a Johnson counter so it uses one more FF than required to divide by 10, but the decoding to 1 of 10 is much easier than a straight binary counter.

The three diodes in series (10 triplets) represent red LEDs with a Vf of around 1.8V.

score -1 · Answer 2 · answered Jun 18 '22 at 02:04

-1

If you really want to solder this..

1 Bit binary counter with discrete components

schematic

^{simulate this circuit – Schematic created using CircuitLab}

answered Jun 18 '22 at 02:04

Jens

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NPN high-edge flipflop

2 Answers2