Physics - Converting AC to DC: half-wave rectification
Converting AC to DC: half-wave rectification
The electricity provided to your home is in an AC format. However many of
the items in your home require DC electricity to operate them. Many of
these items are electronic devices that need relatively small voltage
signals, of the order of 9 to 12 volts DC.
The first step when converting from AC to DC electricity may involve
stepping down the AC voltage to a more suitable level. This would involve
the use of a step-down transformer as described previously in this unit.
The next step is to convert a signal that is alternating in its direction
of current flow into a current that flows only in one direction. The
simplest (but not the most efficient) way of doing this is to employ a
single diode as shown. An AC signal input to this circuit would only result
in current flow during half of each cycle as the diode would block the path
of any 'backward' flowing current. Although the objective of producing
uni-directional current has been achieved, for half the time no current
flows at all. This process is called half-wave rectification, and the
resulting signal requires further modification before it can be utilised.
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