(1) (
Voltage
Controlled
Oscillator) An oscillator that can be tuned over a wide range of frequencies by applying a voltage (tuning voltage) to it. Used in many applications such as radio tuners, VCOs are less costly than crystal oscillators, but not as stable. Contrast with
crystal oscillator.
(2) (
Voice
Carry
Over) A telephone that allows deaf people to read incoming messages from a relay service, but lets them use their voice to respond.