Self-excited intermittent oscillation circuit diagram

Crystal Oscillator

Quartz Oscillator 3225 20M OSC

This article explores the concept of a self-excited intermittent oscillation circuit. An oscillating current is a type of electrical current that changes in both magnitude and direction over time, following a periodic pattern. A circuit designed to produce such a current is known as an oscillating circuit. The most basic form of this circuit is called an LC circuit, which consists of an inductor and a capacitor connected in a loop.

Oscillating currents are essentially high-frequency alternating currents (AC). Unlike the AC generated by rotating coils in magnetic fields, these currents are produced specifically through an oscillating circuit. This makes them essential in various electronic applications, including radio transmission, signal processing, and timing systems.

When the circuit is first powered on (at time t = t₀), current flows through the primary winding of the transformer to the collector, creating an induced voltage u₁ and a secondary sense voltage u₂. The polarity of u₁ alternates, and this causes u₂ to change accordingly. As u₂ increases, it further amplifies the voltage across the base, triggering a positive feedback effect known as "avalanche." This process sustains and strengthens the oscillation within the circuit.