
The schematic diagram shown in the figure below show a function generator circuit using CA3130 in the integrator the threshold detection sections. Both triangular and square-wave signal are available from this circuit’s output, ranging from 0.1Hz to 100KHz (1:1000000 ratio). This frequency adjustment is done only by a single control R1. A voltage control input [...]
Read the rest of this article [..]

Using a single supply quad comparator LM339, LM239, LM2901, LM2901V, NCV2901, or MC3302, we can build a square-wave oscillator with simple circuit and formula. Here is the schematic diagram: This circuit is suitable if you need many square-wave oscillators in one circuit, since the quad packaged comparator provide four comparators in one single [...]
Read the rest of this article [..]

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 [...]
Read the rest of this article [..]

This circuit is similar to our previous tone control circuit, a bass-treble tone control circuit, but here we present the formula for design your tone control’s custom frequency response. Here is the schematic diagram and formula of the tone control circuit: Almost all op-amp type can be used, as long as they have [...]
Read the rest of this article [..]

The simple low-pass filter is shown in Figure below. The filter has a 20dB/decade roll-off after its corner frequency fc. Its low-pass frequency gain (f->0) is defined by R3/R1. This allows low-frequency gains other than unity to be obtained. R2 should be chosen equal to the parallel combination of R1 and R3 to minimize error [...]
Read the rest of this article [..]

Waveform generator is very useful in electronic experiment and design. This circuit generate sine wave oscillation, but actually we can modify the circuit to generate triangle or square wave function. Lets see its schematic diagram first, here it is: The core of this waveform generator is MAX038. This integrated circuit chip gives complete [...]
Read the rest of this article [..]