doubt in auto search

[chandra999777]

hey guys i want to know how exactly auto search feature works in our fm radios. without manually tuning how could it automatically changes frequency .

 

[MikeMl]

Are you asking about "scanning" to find stations? Since the local oscillator is a voltage-controlled oscillator (VCO) driven by a digital frequency synthesizer phase-locked loop (PLL), it is simple to step through all of the preassigned channels sequentially (simple digital counter). When the receiver lands on a channel with a signal on it, the signal is demodulated, and is used to stop the scan. The logic for this is implemented in a micro-controller which manages the memories and frequency display, too.

 

[audioguru]

On CDs, MP3s and FM radio my car radio shows who sings or which group plays and shows the name of the song.
Of course it also scans radio stations.