POWER SUPPLY
Bridge type full wave rectifier is used
to rectify the ac output of secondary of 230/09V
Step down transformer. This project uses
regulated 5V, 500mA power supply. 7805 three
Terminal voltage regulator is used for
voltage regulation.
Mains Transformer:
It is a Step-Down power transformer that operates at power line Frequency of
50Hz. It converts 230v AC into 0 to 09v DC.
Rectifier Circuit:
It is a Full-Wave Bridge Rectifier consisting of four IN4007 diodes.
Filter Section:
It consists of a capacitor C1, which has a capacitance of 1000micro Farads. It
is large enough to supply a constant current to the load during the non
conduction period of the diode
Regulators: 5v voltage regulator-7805 .
Operation:
The
transformer provides voltage transformation and produces AC voltage required
for producing the desired DC voltages across its secondary windings. It also
provides electrical isolation between the power supply input i.e., AC mains and
DC output. The rectifier circuit changes the AC voltages appearing at
transformer secondary to DC. Commonly used rectifier circuits include half-wave
rectifier, conventional full-wave rectifier requiring a tapped secondary or a
bridge rectifier.
The rectified voltage will always have some AC
content known as power supply ripple. The filter circuit smoothens the ripple
of the rectified voltage. The filtering action of the capacitor connected
across the output of the rectifier comes from the fact that it offers a low
reactance to AC components. The ripple in nature is inversely proportional to
capacitance. Thus, the capacitor connected across the output of the rectifier,
which provides the filtering action, must be large enough to avoid the ripple.