Multiplying pulse widths circuit

Description: A circuit designed to multiply the width of incoming pulses by a factor that can be greater or less than unity is straightforward to construct. It features a single adjustable potentiometer for selecting the multiplying factor. This factor is established by configuring the potentiometer in the feedback loop of a 741 operational amplifier. The input pulses, characterized by width (r) and repetition period (T), trigger a sawtooth generator at their rising edges, which produces a waveform (e2) with a peak value of (E) volts. The peak value is subsequently sampled by the input pulses to create a pulse train (e3) with an average value of (e4 = t/T), which is proportional to the width (t) and independent of the period (T). The direct current voltage (e4) is then amplified by a factor (k) and compared with the sawtooth waveform (e2), resulting in output pulses with a duration of (kt). This circuit operates effectively within the frequency range of 10 kHz to 100 kHz.

The described pulse width multiplication circuit effectively utilizes a 741 operational amplifier configured in a feedback arrangement with a potentiometer to determine the multiplication factor. The incoming pulse width and repetition period are critical parameters that dictate the circuit's performance. The sawtooth generator, triggered by the rising edges of the input pulses, generates a triangular waveform (e2) that serves as a reference for sampling.

When the input pulses sample the peak value of the sawtooth waveform, a new pulse train (e3) is produced. The average value of this pulse train (e4) is directly proportional to the width of the input pulses and inversely proportional to the repetition period, allowing for precise control over the output characteristics. The subsequent amplification of the average voltage (e4) by a factor (k) enhances the signal strength before it is compared with the sawtooth waveform.

The output pulses, characterized by a duration of (kt), provide flexibility in the design, enabling the circuit to adapt to various applications requiring pulse width modulation. The operational frequency range of 10 kHz to 100 kHz indicates the circuit's suitability for a variety of electronic applications, including signal processing and waveform generation. The simplicity of the design, combined with the ease of adjustment through a single potentiometer, makes this circuit an efficient solution for pulse width multiplication tasks.A circuit for multiplying the width of incoming pulses by a factor greater or less than unity is simple to build and has the feature that the multiplying factor can be selected by adjusting one potentiometer only. The multiplying factor is determined by setting the potentiometer in the feedback of a 741 amplifier.

The input pulses of width r and repetition period is used to trigger a sawtooth generator at its rising edges to produce the waveform e2 having a peak value of (E) volt. This peak value is then sampled by the input pulses to generate the pulse train e3 having an average value of e4(= t/) which is proportional to t and independent on T. The dc voltage e4 is amplified by a factor k and compared with sawtooth waveform e2 giving output pulses of duration k t.

The circuit is capable of operating over the frequency range 10 kHz - 100 kHz.