555 timer voltage controlled oscillator


Posted on Feb 7, 2014

This is a circuit of a voltage-controlled oscillator (VCO) that uses the 555 timer IC as the main component. As expected, the 555 timer is configured as an astable multi vibrator to be able to serve as an oscillator. An astable multi vibrator is just a timing circuit whose output oscillates between `low` and `high` continuously, in effect generati


555 timer voltage controlled oscillator
Click here to download the full size of the above Circuit.

ng a train of pulses. This is the figure of the circuit; The difference of this circuit with the basic 555 astable circuit is that its 555`s pin 5 is tied to an external voltage source. Pin 5 is the 555`s control voltage pin, which allows the user to directly adjust the threshold voltages to which the pin 2/pin 6 input voltages are compared by the 555`s internal comparators. Since the outputs of these comparators control the internal flip-flop that toggles the output of the 555, adjusting the pin 5 control voltage also adjusts the frequency at which the 555 toggles its output. Increasing the input voltage at pin 5 decreases the output oscillation frequency while decreasing the input voltage increases the output oscillation frequency.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Code-Practice Oscillator Iii
Monitoring Voltages with Scaling Circuits
zener Floating Voltage to Bias a P-Channel Mosfet without Exceeding Source-Gate Max Voltage
guitar amplifier electronic 60 watt
Bluish Flasher
Electronic amplifier
USB Bootloader
Combustible gas alarm circuit diagram 7812 7805 555



Top