06-09-2017, 10:13 AM
The most popular types of linear and fixed output voltage regulators are by far the series of positive output voltage of 78 ... and the series of negative output voltage of 79 .... These two types of complementary voltage regulators produce a precise and stable voltage output ranging from about 5 volts to about 24 volts for use in many electronic circuits.
There is a wide range of these three terminal fixed voltage regulators each available with its own built-in voltage regulation and current limiting circuits. This allows us to create a whole series of different rails and power outlets, whether single or double power, suitable for most electronic circuits and applications. There are even variable voltage linear regulators available as well as providing an output voltage that is continuously variable from just beyond zero to a few volts below its maximum voltage output.
Most d.c. power supplies are composed of a large transformer and heavy network transformer, rectifying diodes, either full-wave or half-wave, a filter circuit to remove any ripple content of the rectified d.c. producing a d.c. suitably smooth. voltage and some type of voltage regulator or stabilizing circuit, either linear or switching, to ensure correct regulation of the output voltage of the power supplies under different load conditions. Then a d.c. typical. Power supply would look something like this:
Typical DC power supply
These typical power supply designs contain a large network transformer (which also provides insulation between the input and output) and a series disipative control circuit. The regulator circuit could consist of a single zener diode or a three-terminal linear regulator to produce the required output voltage. The advantage of a linear regulator is that the power circuit only needs an input capacitor, an output capacitor and some feedback resistors to adjust the output voltage.
Linear voltage regulators produce a regulated DC output by placing a continuously conducting transistor in series between the input and the output that operates it in its linear region (hence the name) of its current-voltage (i-v) characteristics. Thus, the transistor acts rather as a variable resistor that is continuously adjusted to whatever value is needed to maintain the correct output voltage.
There is a wide range of these three terminal fixed voltage regulators each available with its own built-in voltage regulation and current limiting circuits. This allows us to create a whole series of different rails and power outlets, whether single or double power, suitable for most electronic circuits and applications. There are even variable voltage linear regulators available as well as providing an output voltage that is continuously variable from just beyond zero to a few volts below its maximum voltage output.
Most d.c. power supplies are composed of a large transformer and heavy network transformer, rectifying diodes, either full-wave or half-wave, a filter circuit to remove any ripple content of the rectified d.c. producing a d.c. suitably smooth. voltage and some type of voltage regulator or stabilizing circuit, either linear or switching, to ensure correct regulation of the output voltage of the power supplies under different load conditions. Then a d.c. typical. Power supply would look something like this:
Typical DC power supply
These typical power supply designs contain a large network transformer (which also provides insulation between the input and output) and a series disipative control circuit. The regulator circuit could consist of a single zener diode or a three-terminal linear regulator to produce the required output voltage. The advantage of a linear regulator is that the power circuit only needs an input capacitor, an output capacitor and some feedback resistors to adjust the output voltage.
Linear voltage regulators produce a regulated DC output by placing a continuously conducting transistor in series between the input and the output that operates it in its linear region (hence the name) of its current-voltage (i-v) characteristics. Thus, the transistor acts rather as a variable resistor that is continuously adjusted to whatever value is needed to maintain the correct output voltage.