Simple Two-Transistor Single-Supply Resistor–Capacitor Chaotic Oscillator

We have modified an otherwise standard one-transistor self-biasing resistor-capacitor phase shift oscillator to induce chaotic oscillations. The circuit uses only two transistors, no inductors, and is powered by a single supply voltage. As such, it is an attractive and low-cost source of chaotic oscillations for many applications. We compare experimental results to SPICE simulations, showing good agreement. We qualitatively explain the chaotic dynamics to stem from hysteretic jumps between unstable equilibria, around which growing oscillations exist.