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Table of Contents
Voltage Controlled Oscillator
This is a small Voltage-Controlled Oscillator - the heart of every analog synthesizer. It provides a square and a triangle wave, and it could be hard synced, too.
The OpAmp is a rail to rail MCP6002 from Microchip.
It is designed to use for experimts and development together with a breadboard.
Schematic
Paper PCB
Parts
- Resistors:
- 1x 1 kOhm
- 2x 10 kOhm
- 1x 12 kOhm
- 6x 47 kOhm
- 1x 100 kOhm
- Capacitors:
- 1x 3.3 nF (foil)
- Electrolytic Capacitors:
- 2x 10 µF
- Semiconductors:
- 1x LED
- 1x OpAmp MCP6002
- 1x BC547 transistor
- Mechanical:
- 1x IC socket, 8 pin
- 2x pin strip 3 pin
- Potentiometers:
- 1x 100 kOhm
Voltage In
Any voltage between 0-5V can control the frequency. Without input resistor the potentiometer wont have any effect. But depending to the value of the input resistor the potentiometer will change the frequency, too.
Voltage Source-------100 Ohm-------- Voltage IN
Sync
For the Sync input one can use any 0-5V source but a resistor and a diode works best.
Sync Source -----resistor------diode-----Sync Input
Output
If one wants to use it as a sound source one needs to attach a resistor and a 47µF capacitor to the output:
+ 47µF square out----470 Ohm-----||-------Line Out | 120 Ohm | GND
+ 47µF triangle out----470 Ohm-----||-------Line Out | 150 Ohm | GND
License
The Voltage Controlled Oscillator was designed by Wolfgang Spahn 2020.
It is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.