Sinewave oscillators ( 20 ) :

Sine wave oscillators are useful in applications likeaudio signal generation, reference signals for differentapplications and in measurement applications.To vary the frequency of a traditional RC filter based sine-wave oscillator, you should generally use a pair of ganged variable resistors, and you should thoroughly match their characteristics over the entire variation range to satisfy the oscillator's balancing conditions. This restriction leads to problems in the tuning range and high cost, thereby limiting the range of applications.

• 1 kHz Audio Oscillator - This circuit consists of a CMOS square wave oscillator on a frequency of approximately 1 kHz. The RC filter, which has a roll-off frequency of 500 Hz, filters the harmonics, providing a sine-wave output. The oscillator has many uses, sidetone circuits in transmitters and signal injectors for audio tests are just two.   
• 68HC11 synthesizes accurate sine wave - you can use a 68HC11 and a 12-bit serial DAC to generate accurate sine waves without using floating-point arithmetic   
• 770 Hz Simple CPO - simple sinewave oscillator   
• Amplitude-stable oscillator has low distortion, low cost - square wave and sinewave oscillator examples    Rate this link
• Audio signal (sinewave) generators - wien bridge oscillators, twin-t network oscillator and RC phase shift oscillator   
• Audio Test Oscillator - Wein Bridge Basic Circuit   
• Current-feedback amp yields simple oscillator - handful of components configures a current-feedback op amp as a large-amplitude sine-wave oscillator with independent adjustment of amplitude and frequency   
• Digital signals produce pure sine waves   
• Gate Deep Oscillator - This is just a variable oscillator based on a bf245 or k 161 fet. By changing the coil it can generate frequency between 0.5 and 300 MHZ. this circuit is useful to test radio circuit such as filter, receiver, transmitter and so on . It can be use for coil tuning thanks to the 100microamo meter built in.   
• Gates provide low-cost sine-wave generator - simple device to generate 300 to 4000 Hz test signals   
• GIC resonator has inherent amplitude control - This circuit is based on a classic GIC (generalized impedance converter). The sine-wave-oscillator circuit has inherent amplitude stabilization and normally operates from dual power supplies. However, if you connect a few additional resistors, you can operate the circuit with one supply.   
• Grounded resistor tunes oscillator - To vary the frequency of any sine-wave oscillator, you usually have to use a pair of ganged variable resistors, and you should thoroughly match their characteristics over the entire variation range to satisfy the oscillator's balancing conditions. This restriction leads to problems in the tuning range and high cost, thereby limiting the range of applications. This sine-wave oscillator is free of the cited disadvantage. You can tune it over a wide frequency range using only one variable resistor. The variable resistor connects to ground, an advantageous fact in many applications. PSpice simulations prove the possibility of tuning the oscillation frequency over three decades (20 Hz to 20 kHz) by varying R1 from 1.2 M. to 1.2 k.
• Grounded resistor tunes oscillator - To vary the frequency of any sine-wave oscillator, you should use a pair of ganged variable resistors, and you should thoroughly match their characteristics over the entire variation range to satisfy the oscillator's balancing conditions. This restriction leads to problems in the tuning range and high cost, thereby limiting the range of applications. This sine-wave oscillator design is free of the cited disadvantage.   
• Microcontroller emulates numerically controlled oscillator - Microcontrollers commonly add intelligence or digital functions to products, but they can also provide a variety of analog signals. An 18-pin PIC 16C54 microcontroller, combined with an inexpensive, 8-bit DAC and a simple lowpass filter, can generate sine waves from dc to approximately 50 kHz with a tuning resolution of 24 bits.   
• Op-amp oscillators simplify RF designs - a novel circuit that uses a low-cost, high-speed op amp as a crystal-controlled RF sine-wave oscillator   
• Programmable oscillator uses digital potentiometers - This Design Idea describes an oscillator in which setting the resistance of two digital potentiometers independently programs the oscillation amplitude and frequency. This design idea uses diode-stabilized Wien-bridge oscillator that generates accurate sine waves from 10 to 200 kHz.   
• Simple circuit generates clean sine waves - technique for generating a high-quality sine wave from a square-wave source   
• Sine reference is synchronous with ac line - Many applications require a sinusoidal reference voltage synchronized to the ac line voltage. You cannot derive such a reference voltage directly from the ac line because the waveform of the ac line is distorted because of nonlinear loads connected to the line and because the amplitude of the line signal varies.   
• Three-Phase Sine-Wave Generator - A circuit generates three-phase sine waves with excellent amplitude and phase symmetry. A variable-frequency, three-phase, sine-wave generator circuit has been designed for use as a source of polyphase excitation in studies of the propagation of traveling waves in plasmas. The circuit internally generates three symmetrical square-wave voltages with precisely 120� phase difference, each square wave containing only odd harmonics. Three switched-capacitor, six-pole Butterworth low-pass filters (U10, U11, and U12) remove the harmonics but pass the fundamental sine-wave component. The operating-frequency range of the circuit, 10 Hz to 10 kHz, is covered in three decade ranges. A Zener-stabilized voltage-controlled oscillator (VCO) functions as a variable-frequency oscillator and covers just over one decade.   
• Voltage controls sine-wave frequency - generates a 50-Hz to 1-kHz sinusoidal waveform that exhibits lower than 60-dB THD   

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