-3

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.

JYelton
  • 32,302
  • 33
  • 134
  • 249
christian gavaller
  • 1
  • "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](https://electronics.stackexchange.com/a/351026/38098) 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

2 Answers2

1

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.

enter image description here

Spehro Pefhany
  • 376,485
  • 21
  • 320
  • 842
-1

If you really want to solder this..

1 Bit binary counter with discrete components

schematic

simulate this circuit – Schematic created using CircuitLab

Jens
  • 5,598
  • 2
  • 7
  • 28