.. 3.1

Half wave rectifier using PN junction
=====================================

**Objective**

Learn the working of a PN junction diode as a rectifier. RC filtering to
reduce the ripple (the AC component).

.. image:: schematics/halfwave.svg
	   :width: 300px
.. image:: pics/halfwave.png
	   :width: 300px

**Procedure**

-  Make connections and observe the output
-  Connect a :math:`1~k\Omega` load resistor, note the difference in amplitude
-  Connect a :math:`1 \mu F` capacitor, and see the filtering effect.
-  Try different values load resistors and filter capacitors

**Discussion**

The negative half is removed by the diode as shown in figure. Also
notice that the voltage in the positive half is reduced by around 0.7
volts, the voltage drop across a silicon diode. A load resistor is
required for the proper operation of the circuit, it could be more than
1kΩ but do NOT use very low values since our AC source can drive only up
to 5 mA current.

We can see that the capacitor charges up and then during the missing
cycle it maintains the voltage. The remaining AC component is called the
ripple in the DC.

Can we use very large capacitance to reduce the ripple ?

During what part of the cycle does current flow through the diode ?

Amount of peak current is decided by what ?
