Here’s the Mono-stable multivibrator circuit generates a fixed pulse width when receiving a trigger signal on its input. The pulse width of the output is fixed regardless of the input pulse duration/width. In practical application, the width of the output pulse is determined by choosing the right components values for certain application. In today’s digital electronics, mono-stable function can be easily implemented using micro controller. In many practical they’re more than enough, but many experimental works sometime need very specific function with high speed performance while maintaining its flexibility. This is the figure of the circuit diagram.
With this circuit schematic
diagram, we can build a voltage controlled pulse width generator, so we can
provide a flexible mono-stable multivibrator for doing many experiment in the
lab. This circuit has two input, the voltage control for controlling the width
of the output pulse, and the trigger input for triggering the output pulse
generation. By adjusting the control voltage between 0 to 2.5V, we can adjust
the width of the mono-stable multivibrator output between 0.05 to 2.5 uS. A
full-scale calibration trimmer is provided to make sure this controlling range.
This control voltage can be generated from a potentiometer (voltage divider) or
from DAC (digital-to-analog converter) of a micro controller. Finally, this
circuit provide two pulse output, the active high and active low (its
inversion) for flexible usage.
