A regulated power source can be any power supply; the only requirement is that it have a consistent output voltage. A regulated power supply might be a linear power supply, an adjustable power supply, or a variable power supply. It can have any voltage value, such as 5V, 10V, 12V, and many more. The advantage of using a regulated power supply is that it removes much of the risk of exposure to high voltages that are common with unregulared power supplies.
For example, if you were to use an unregulated power supply to power a motor, there would be a chance that the voltage might be high enough to cause damage to either the power supply or the motor. With a regulated power supply, this problem goes away because the regulator will always keep the voltage at a safe level.
Also, unregulated power supplies can produce large amounts of noise due to their lack of regulation. This noise may interfere with other circuits on your project board and could also be harmful if it is an AC power source and comes into contact with metal objects.
So yes, there is a need for a regulated power supply in any project that has components that are exposed to risk of damage from high voltage sources.
A regulated power supply, in electrical terminology, delivers a consistent output voltage that is independent of the output current. A regulated power supply with numerous regulators can provide a variety of output voltages for powering various devices. An unregulated power supply produces voltage drops that are dependent on the load it is supplying.
A regulator uses feedback information from its input (the supplied voltage) and its output (the delivered voltage) to regulate the amount of energy that is delivered to the output. This allows the regulator to maintain a constant output voltage even if the input voltage varies.
The two main types of regulators are switching-mode regulators and linear regulators. Switching-mode regulators such as buck converters use a switch to control the flow of current through an inductor or capacitor. The switch may be implemented using transistors, which are easy to control but have large parasitic capacitances that limit the frequency at which they can be operated. Linear regulators such as diode-based resistors operate by forcing constant current through the resistor regardless of how much voltage is applied. They are less efficient than switching-mode regulators but are capable of higher frequencies because they do not contain any moving parts.
Regulated power supplies are essential for many appliances and electronic devices that require a constant voltage source.
The use of a regulated power source ensures that the output stays consistent even if the input fluctuates. A regulated DC power supply, often known as a linear power supply, is a multi-block integrated circuit. The regulated power supply will receive an alternating current input and provide a constant direct current output. This is useful for devices that must function properly under certain conditions, such as lights that need to shine steadily regardless of fluctuations in the power line.
Linear power supplies are used in many appliances that require a constant voltage source for their operation. These include computers, televisions, stereo systems, and various other consumer electronics products. In addition, they can be found in any device that requires a steady stream of electrons to operate reliably, such as lasers and LED lighting. Because these supplies are integral to so many products, they have been adopted into many industrial settings where continuous, reliable power is required.
There are several types of linear power supplies, each with different advantages and disadvantages. They all produce a fixed voltage no matter what the load demands are, but differ in how much current is delivered while maintaining this fixed voltage. Some power supplies can switch between delivering a high current and low current depending on which mode you need at the time. Others can only deliver a fixed maximum current or a fixed minimum current - they cannot vary their output within one single cycle.
Linear regulated power supplies receive their name from the fact that they employ linear, or non-switching, approaches to regulate the power supply's voltage output. The phrase "linear power supply" refers to a power supply that is controlled to give the right voltage at the output. Such supplies were originally based on magnetic circuits with iron plates and magnets, but modern equivalents are made using semiconductor technology.
In general, all power supplies must make some form of regulation to ensure that the output voltage is within specified limits. This may be done in several ways: by switching on and off the current through a load (switch-mode power supplies), by adjusting the amount of current drawn from the mains (current-limiting power supplies), or by providing a constant voltage regardless of how much current is being drawn from the mains (voltage-regulating power supplies).
A linear regulated power supply works by comparing the output voltage with a reference voltage. If there is a difference between them, an error signal is generated which controls a regulator circuit. This may be anything from a simple on/off switch to a more sophisticated circuit such as a pulse-width modulator. The regulator then adjusts the input to the supply so that the output matches the reference voltage in value but not necessarily in phase. Thus the word "regulated" means that the voltage supplied will be consistent but not necessarily equal to the reference voltage.
The less load regulation there is, the more stable and dependable the power supply is. Typical well-regulated power supplies have load regulations of less than 1%, which means that the output voltage will fluctuate by no more than 1% across the supply's load current range. Power supplies with load regulations of 5% or 10% are common but can also be found for very low load currents.
In practice, most power supplies have load regulations between 15% and 100%. These lower limits are imposed by the electronics used to control power delivery to reduce stress on those components and extend their life. Load regulators typically have maximum load capacities of about 100 watts so don't worry about power supplies being able to handle huge loads occasionally. A load regulation of 15% means that the output voltage will fluctuate by 15% across the supply's load current range. Not all power supplies have load currents measured in milliamps, so be sure to check the specifications before you buy a product.
Stable power supplies are essential for good performance in high-end audio equipment and other precision applications where small fluctuations in voltage or current may cause problems. Some power supply manufacturers claim load resistances below 150 ohms as an advantage, but this is not necessary for good regulation quality. Resistors above some minimum value are needed only because that is how many circuits are built into each power supply. In general, though, fewer components mean lower costs for consumers.