Free Circuit Diagram

Sine wave oscillator can be implemented using Wien-Bridge oscillator like in our previous sine wave oscillator circuit, but now we present another method of generating sine wave signal. Using phase shifter, we can build a simple sine wave generator, as shown in the schematic diagram below: Sine wave oscillator using phase shifter has [...]

This circuit detect the amplitude of audio signal, suitable for audio level detection that demand for high precision. Amplitude detection or signal envelope detection is usually implemented using a peak detector. An ideal amplitude detector give continuous level at any time because the amplitude of a sine signal (every signal can be seen as sine [...]

The excellent high input impedance, high slew rate, and high voltage qualities of CA3140 op-amp make it suitable for Wien-bridge sine wave oscillator. The basic circuit for Wien-bridge sine wave oscillator is shown in the figure below (the upper part). You can see the formula in the figure, when R1=R2=R, and C1=C2=C, then the formula [...]

Notch filter is known as band-cut filter or band-reject filter. The fuction of this filter is to remove some frequency portion of a signal. The schematic diagram of this filter circuit, a second order notch filter is depicted in the figure below. The formula is actually complicated, but by taking the R3=R4 and [...]

This sine wave generator is adjustable between 15 Hz to 150 kHz. The circuit is basically a Wien-bridge oscillator, with multiple capacitor selection. Here is the schematic diagram: A stereo 10k potentiometer is used to control the frequency. The dashed line connecting these two potentiometers show that both potentiometer has single axis.