Definition
An electronic circuit that produces a non-sinusoidal repeating output, typically a sawtooth or square wave, by alternately charging a capacitor through a resistor and then rapidly discharging it when a threshold voltage is reached. The cycle repeats automatically, producing a steady train of pulses whose frequency is set by the resistor and capacitor values.
Plain English
A circuit that slowly builds up a voltage, suddenly dumps it, and then starts building again. This repeating build-and-dump action creates a steady rhythm of electrical pulses.
Context Anchor
Seen in aircraft electrical and avionics discussions for circuits that need regular pulses, timing, or flashing action.
Derivation
From Latin relaxare, meaning 'to loosen' or 'release'. The name describes how the circuit slowly builds up energy and then 'relaxes' by releasing it suddenly, repeating the process. 'Oscillator' comes from Latin oscillare, 'to swing', describing any circuit that produces a repeating output.
Why Pilots Care
A relaxation oscillator may be part of a circuit that controls pulsing or timing. If that circuit fails, the equipment it controls may stop flashing, pulsing, or timing correctly.
Analogy
Think of a toilet cistern. Water slowly fills the tank, and when it reaches a set level, it dumps all at once and starts filling again. The relaxation oscillator does the same thing with electrical charge instead of water.
Grounding Statement
Picture an electrical circuit slowly building up charge, then suddenly releasing it, again and again.
Intuition Check
“Relaxation” does not mean the circuit is calm or less active. It means the circuit repeatedly releases a built-up electrical condition and returns toward its normal state.
Example Sentence 1
The technician traced the timing problem to a faulty relaxation oscillator in the radar sweep circuit.
Example Sentence 2
A technician replaced the capacitor in the relaxation oscillator to restore the correct flash rate of the beacon light.