Compact BJT 2-Bit Counter

Job ID: 40585833

Budget: $10 – $30 USD

need a straightforward 2-bit counter designed entirely with discrete Bipolar Junction Transistor (BJT) logic. My priority is to keep the component count as low as practical while still delivering clean, glitch-free counting through the four binary states (00-01-10-11).


• Use only BJTs – no FETs, ICs, or microcontrollers
• Favor the fewest possible transistors and passives without compromising function
• Standard 5 V logic levels are ideal, though I’m open to 3.3 V if that helps reduce parts

Ultimately, the most important thing is that the design works practically on the breadboard—without issues and without noise.