Sine wave

Wien Bridge RC Sinewave Oscillator

Three examples of Wien Bridge oscillators are shown below. The first uses three bipolar transistors. The second uses a bipolar and JFET, and the third is the more popular type using an op-amp for minimal parts. The idea is to generate a 360 degree phase shift at some particular frequency using 2 resistors and caps of equal value. One cap and resistor are in series, while another cap and resistor are in parallel. The signal loss through the network is about 66 percent so the amplifier gain needs to be around 3 for a loop gain of 1. The gain of the amplifier is critical since too much gain will produce a clipped (distorted) waveform and not enough gain will not sustain oscillation. ..

Sinewave Generator schematics

The two circuits below illustrate generating low frequency sinewaves by shifting the phase of the signal through an RC network so that oscillation occurs where the total phase shift is 360 degrees. The transistor circuit on the right produces a reasonable sinewave at the collector of the 3904 which is buffered by the JFET to yield a low impedance output. The circuit gain is critical for low distortion and you may need to adjust the 500 ohm resistor to achieve a stable waveform with minimum distortion. The transistor circuit is not recommended for practical applications due to the critical adjustments needed. ..

Function Oscillator using 8083

Built around a single 8038 waveform generator IC, this circuit produces sine, square or triangle waves from 20Hz to 200kHz in four switched ranges. There are both high and low level outputs which may be adjusted with the level control. This project makes a useful addition to any hobbyists workbench as well. The waveform generation is produced by IC1. This versatile IC even has a sweep input, but is not used in this circuit. The IC contains an internal squarewave oscillator, the frequency of which is controlled by timing capacitors C1 - C4 and the 10k potentiometer. The tolerance of the capacitors should be 10% or better for stability. ..

Tunnel Diode Oscillator

The excess small forward current flow in a tunnel or Esaki diode is a manifestation of quantum mechanical tunneling...

Function Generator, capacitance and inductance meter

This site contains complete schematics and code for a 68HC11 based frequency counter, square wave synthesizer, sine wave synthesizer, programmable filter, capacitance and inductance meter, with a digitalker speech synthesizer output. Project specifications are given below...

Function Generator Sine / Triangle / Square / Saw ( PIC16F870 )

After the recent demise of our multifunction signal generator, we decided to make one of our own. The circuit uses a PIC16F870 (about $3), an R/2R resistor ladder network (for a real fast and cheap D/A), and a few other parts. You can check out the schematic and the current source file. Also the object (hex) file. All of the sine wave functions utilize a full 256 byte by 8 bit lookup table. Contrary to what you may have heard elsewhere, it is possible to use a full memory page in the PIC for a lookup table - check it out...

Digital Sine Wave Oscillator

If found myself in need of a 1 KHz signal source for an experiments. My function/sweep generator was needed as a pulse generator for the same experiment, so I went though my junk box, looking for circuits from long ago that might fill the need, but found nothing useful. I had a board with an AT90S8515 and an 8 bit resistor ladder network on it, which serves as a DAC (digital to analog converter), so I thought "This will be easy." and sat down to write the code. Since I wrote it in C rather than assembly, writing the code took much longer than I expected, but in the end, I managed to get it to do what I wanted it to do, and I fixed the typographical errors. ..

Frequency Sine wave generator with MAX083

This circuit uses the versatile MAX038 function generator. Although in this circuit some of the advanced characteristics of this IC are disabled, you can generate Sine, Triangle, Square waves (adjusting A0 and A1 pins see datasheet on www.maxim-ic.com if you want other waves, use a switch). The signal is amplified through a TCA0372 (from ONSEMI) Power opamp with current capability up to 1A and bandwitch up to 1 MHz. I selected this particular frequency (122 Khz) because i needed a cheapo ESR-o-meter for my electrolytic capacitors to monitor their health as they have to discharge tens of amperes in less than 2 ms. At 122 KHz capacitive reactance is very low, and inductive reactance isn't so high, so forcing a current (es 200mA, using a precision resistor) through a capacitor and reading AC voltage drop accross it gives me an estimation of ESR (Vdrop/current). Of course inductive and capacitive reactance are still present, but negligible...

Adjustable Sine Square Wave Oscillator

This is a adjustable sine square wave oscillator circuit...

The LM12 is a power op amp capable of driving ±25V at ±10A while operating from ±30V supplies. The monolithic IC can deliver 80W of sine wave power into a 4 load with 0.01% distortion. Power bandwidth is 60 kHz. Further, a peak dissipation capability of 800W allows it to handle reactive loads such as transducers, actuators or small motors without derating...

Figure 2 shows a block diagram for this sine-wave generator. You can easily analyze the generator`s behavior by writing state equations in the z domain. You can also write equations in the s domain. The location of the two poles on the right-hand side reveals the generator`s oscillatory nature. The inverse Laplace transformation is simple and results in a sine-wave statement...

This circuit generates a good 1KHz sinewave adopting the inverted Wien bridge configuration (C1-R3 & C2-R4). It features a variable output, low distortion and low output impedance in order to obtain good overload capability. A small filament bulb ensures a stable long term output amplitude waveform. Useful to test the Precision Audio Millivoltmeter, Three-Level Audio Power Indicator and other audio circuits posted to this website...

This circuit generates a good 1KHz sinewave adopting the inverted Wien bridge configuration (C1-R3 & C2-R4). It features a variable output, low distortion and low output impedance in order to obtain good overload capability. A small filament bulb ensures a stable long term output amplitude waveform. Useful to test the Precision Audio Millivoltmeter, Three-Level Audio Power Indicator and other audio circuits posted to this website...

You can use a 68HC11 and a 12-bit serial DAC (Figure 1) to generate accurate sine waves without using floating-point arithmetic. Figure 2 shows a block diagram for this sine-wave generator. You can easily analyze the generator`s behavior by writing state equations in the z domain. You can also write equations in the s domain. The location of the two poles on the right-hand side reveals the generator`s oscillatory nature. The inverse Laplace transformation is simple and results in a sine-wave statement...

The multivibrator is a common circuit that consists of an amplifier with both positive and negative feedback (Figure 1a). When the output is positive, the positive input terminal equals ½V+, and the voltage at the negative input terminal changes toward V+. When this voltage exceeds ½V+, the output voltage rapidly changes to V. The positive input terminal becomes ½V, and the negative input terminal changes toward V...