Simple-vco


Posted on Feb 20, 2013

The output frequency of the VCO, U1, varies inversely with the input voltage. With a 1 `V input, the oscillator output frequency is about 1500 Hz; with a 5-V input, the output frequency drops to around 300 Hz. The output frequency range of U1 can be altered by varying the values of C1, R2, and R3. Increasing the value of any those three components will lower the oscillator frequency, and decreasing any of those values will raise the frequency. Output-waveform gymmetry suffers since the frequency varies from one extreme to the other.


Simple-vco
Click here to download the full size of the above Circuit.

At the highest frequency, the waveform is almost equally divided. But when the frequency drops, the output of the circuit turns into a narrow pulse. If a gymmetrical waveform is required, add the second IC, U2, half of a 7473P dual TTL J-K flip-flop, to the oscillator circuit. The signal frequency output by U2 is "iz of the input.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Power Supply for TTL
Low-flow-rate-thermal-flowmeter
0-24VDC Digital PIC Power Supply circuit diagram
A Bedside Lamp Timer Circuit Schematic
Simple TV Transmitter circuit diagram (VHF)
PWM Speed Control Circuit Using Forward-Reverse and Regenerative Braking
Astable Multivibrator using NE 555 timer IC
Vintage Remote TV-B-Gone Case Mod
78xx Voltage Regulators
Improved Anode Circuit Parasitic Suppression for Modern Tubes
Lamp automatic exchange regulator circuit schematic
Normally closed contact burglar alarm circuit diagram
2Y-Y-2 - connection four-speed motor contactor control circuit



Top