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This is simple Comparator Based Crystal Oscillator Circuit Project . Although a simple crystal oscillator may be built from one comparator of an LT1720/LT1721, this will suffer from a number of inherent shortcomings and design problems. Although the LT1720/LT1721 will give the correct logic output when one input is outside the common mode range, additional delays may occur when it is so operated, opening the possibility of spurious operating modes. Therefore, the DC bias voltages at the inputs have to be set near the center of the LT1720/LT1721’s common mode range and a resistor is required to attenuate the feedback to the non-inverting input. Unfortunately, although the output duty cycle for this circuit is roughly 50%, it is affected by resistor tolerances and, to a lesser extent, by comparator offsets and timings. Comparator Based Crystal Oscillator Circuit Diagram If a 50% duty cycle is required, the circuit shown here creates a pair of complementary outputs with a forced 50% duty ...

Here is some important ADVANTAGES and DISADVANTAGES OF RC PHASE SHIFT OSCILLATORS ADVANTAGES OF RC PHASE SHIFT OSCILLATOR. 1. It is cheap and simple to design because it contains only one transistors with some Resistors and Capacitors. 2. It provides good Frequency stability. 3. Circuit is simpler than other OSCILLATOR. 4. It doesn't need any negative feedback and stabilisation arrangements. 5. The output is Sinusoidal so it is quite Distortion Free. 6. Having wide operating Frequency range. 7. Also suitable for low Frequencies. DISADVANTAGES OF RC PHASE SHIFT OSCILLATOR. 1. The output is small due to smaller feedback. 2. It is difficult for the Circuit to start oscillations. 3. The Frequency stability is not so Good. 4. It requires high Vcc. For large feedback. Back to MYCIRCUITS9

OPERATIONAL AMPLIFIER OP-AMP OSCILLATOR ELECTRONIC CIRCUIT Timing capacitor (C1) produces several times constants which is used to allow large voltage swings on the input due to the LM101's large input voltage range. The R2 should be reduced and the C1 should be increased to keep from exceeding these ratings. The smaller polarized capacitors is still used by returning them to positive supply voltage instead of ground, even though C1 requires the large values.

Simple triangle-square wave oscillator circuit diagram . In this circuit by making Rt variable it is possible to alter the operating frequency over a 100 to 1 range Versatile triangle/square wave oscillator has a possible frequency range of 0 Hz to 100 kHz. Triangle Square wave Oscillator Circuit Diagram

Although a simple crystal oscillator may be built from one comparator of an LT1720/LT1721, this will suffer from a number of inherent shortcomings and design problems. Although the LT1720/LT1721 will give the correct logic output when one input is outside the common mode range, additional delays may occur when it is so operated, opening the possibility of spurious operating modes. Therefore, the DC bias voltages at the inputs have to be set near the center of the LT1720/LT1721’s common mode range and a resistor is required to attenuate the feedback to the non-inverting input. Unfortunately, although the output duty cycle for this circuit is roughly 50%, it is affected by resistor tolerances and, to a lesser extent, by comparator offsets and timings.  Comparator Based Crystal Oscillator Circuit Diagram If a 50% duty cycle is required, the circuit shown here creates a pair of complementary outputs with a forced 50% duty cycle. Crystals are narrow-band elements, so the feedback to the...

Here is a phase-shift audio oscillator with excellent distortion characteristics thanks to “softened” diode limiting provided by the 1N914 and resistor divider and degenerated gain provided by the 68 ohm emitter resistor. For minimum distortion, increase the 68 ohm resistor to a point just below where oscillation stops. A simple buffer may be added for driving lower impedance loads. The output amplitude will be about 5 volts p-p but one of the 1N914 ’s 10k divider resistors may be changed for a different output amplitude. The circuit will work well with a power supply voltage other than 9 volts but the 68 ohm resistor may need adjustment