1445326735900-0

Diodes II
Filter tips
Although we’ve managed to obtain a full-wave rectified d.c.
load voltage we still have the problem that this voltage is not
too steady (ideally we would like a fixed d.c. voltage which
doesn’t vary at all). We can reduce the up-and-down variability
of the waves by adding a capacitor to the circuit output. If
you remember, a capacitor stores charges — so we can use
it to average out the variation in level of the full-wave rectified
d.c. voltage. Figure 7.12 shows the idea and a possible
resultant waveform. This process is referred to as smoothing
and a capacitor used to this effect is a smoothing capacitor.
Sometimes the process is also called filtering.
Figure 7.12 Levelling the rectifier d.c. with the help of a capacitor: the process
is known as smoothing
159