AC and the conversion to DC
Direct Current. (a) DC Sources. (b) DC Flow. (c) Graphic Representation of DC.
Alternating Current. Voltage that varies in amplitude and polarity as a function of time
AC Power Distribution.
AC Wave Shapes. (a) Sine Wave. (b) Square Wave. (c) Pulse Wave. (d) Triangular Wave. (e) Sawtooth Wave. (f) Irregular Wave.
Sine Wave Characteristics
Transformers only work with Alternating Current because
.
Where
is the magnitude of the EMF in volts and ΦB is the magnetic flux (strength) through the circuit
Transformer Action.
A transformer is a device that transfers electrical energy from one
circuit to another through inductively coupled conductors
the transformer's coils.
A varying current in the first or primary winding creates a varying
magnetic flux in the transformer's core and thus a varying magnetic
field through the secondary winding.
This varying magnetic field induces a varying electromotive force
(EMF), or "voltage", in the secondary winding. This effect is called
inductive coupling.
If a load is connected to the secondary, current will flow in the
secondary winding and electrical energy will be transferred from the
primary circuit through the transformer to the load. In an ideal
transformer, the induced voltage in the secondary winding (Vs) is in
proportion to the primary voltage (Vp), and is given by the ratio of the
number of turns in the secondary (Ns) to the number of turns in the
primary (Np) as follows:
Transformer Action.
Center-Tapped Utility Pole Transformer.
DC Power Supply. (a) Block Diagram. (b) Built-In Subsystem. (c) Stand-Alone Unit.
Half-Wave Rectifier. (a) Basic Circuit. (b) Positive Input Half-Cycle Operation. (c) Negative Input Half-Cycle Operation. (d)
Input/Output Waveforms. (e) Half-Wave Output Minus Diode Barrier Voltage.
Half-Wave Rectifier.
Percent of Ripple Out of a Filter.
V peak (ripple)
VRMS (ripple)
1
Peak to Peak ripple
2
0.707 V peak (ripple)
Vavg (ripple) Vmid ( Peak to Peak )
% ripple
VRMS of ripple
100
Vavg of ripple
Full-Wave Center-Tapped Rectifier. (a) Basic Circuit. (b) Positive Input Half-Cycle Operation. (c) Negative Input Half-Cycle Operation.
Input/Output Waveforms of a Full-Wave Center-Tapped Rectifier.
Full-Wave Bridge Rectifier. (a) Basic Circuit. (b) Positive Half-Cycle Operation. (c) Negative Half-Cycle Operation.
Capacitive Filtering of a Half-Wave Rectifier Output.
Capacitive Filtering of a Full-Wave Rectifier Output.
Function of a Regulator.
Zener Diode Regulator.