In which type of oscillator, the output frequency is dependent on the amplitude of input voltage ?
In which type of oscillator, the output frequency is dependent on the amplitude of input voltage ?
a. Quadrature Oscillator
b. Voltage Controlled Oscillator
c. Wein-bridge Oscillator
d. Phase-Shift Oscillator
Correct Answer : b. Voltage Controlled Oscillator
Explanation :
Generally, the time constant helps in determining the frequency of oscillation in any oscillator. But, in some of the applications like Frequency Modulation (FM), Frequency Shift Keying (FSK) where the frequency needs to be controlled by input voltage. This input voltage performs the functionality of controlling voltage level & hence, precisely referred as 'Control Voltage'. This entire functionality is undertaken by Voltage -Controlled Oscillator (VCO). Another name of VCO is Voltage to frequency converter.
For e.g. Signetics NE/SE 566 VCO generates the triangular as well as square wave outputs simultaneously as a function of an input voltage. VCO are applicable in conversion of low-frequency signals into audio frequency ranges especially in bio-medical applications EEG (electroencephalograms) & ECG (electrocardiograms).