Page 1050 - Basic Electrical Engineering
P. 1050
Figure 15.11 Bridge rectifier with a smoothing capacitor
using the relation,
Capacitors of 100 μF are available as can be checked from the
manufacturer’s list.
Similar to the capacitor filter used in half-wave rectifiers, capacitor filters
are used in full-wave rectifier also as shown in Fig. 15.11. The circuit works
exactly the same way as has been explained in the case of half-wave rectifier
with a capacitor filter. From the dc output voltage wave shape it is observed
that the ripple is minimized to a very small level.
The ripple voltage that appears across the capacitor can further be reduced
by use of another resistor and a capacitor. The resistor is connected in series
while the capacitors are in parallel making a π formation. Such filters are
called R–C filters or simply π filters. Similarly, we can use L–C filters also to
further smoothen the output voltage. An inductor in series with the load also
works as a filter as the inductor allows dc current to flow and opposes ac
current flow.
15.3 APPLICATIONS OF DIODES IN CLIPPING AND CLAMPING CIRCUITS
A clipping circuit removes, i.e., clips off a certain portion of the input voltage
wave form. Clipping circuits are used when it becomes necessary to protect a
