Almost any electronic equipment requires the use of power supplies. The fact is that the voltage of the network very often does not coincide with what most devices need, especially since they need to provide constant and uninterrupted power. Too low voltage or high surges in the network quickly disable any equipment. A solution to this issue has been found for a long time - the use of a power supply unit that regulates voltage and a protective device.
Today, a linear and switching power supply is used. The first has gained distribution because of its simplicity, quick response to any changes in loads and stability. But there are also disadvantages: low efficiency, cumbersome transformer, sensitivity to input voltage, as well as heat dissipation. For these reasons, linear power supplies are slowly being supplanted by switching ones, which have relatively better characteristics.
Nowadays, miniaturization of equipment is observed, therefore, transformer power supply circuits are no longer relevant. A switching power supply has a huge number of advantages, among which it is worth highlighting the saving of winding material, and this also reduces the cost of the device itself, accurate dimensions, reliability, a wide operating range. These qualities could not go unnoticed by radio amateurs and professionals. True, there is a drawback: even a simple switching power supply has a complex circuit in the assembly and configuration, but this fact does not stop the real masters.
Although UPSs are more expensive than conventional units, they not only receive and transmit power to the devices, but also stabilize it, protecting itself and cascades from various troubles. Today, a switching power supply is widely used for an audio frequency amplifier, devices based on microcontrollers, automation equipment and other various equipment. Initially, they were used in television receivers and various video equipment.
The switching power supply has already established itself as an economical, reliable and easy to use device. Now manufacturers are engaged only in improving the existing models in terms of miniaturization of the element base, as well as improving the reliability of the device itself.
There are a huge number of UPS schemes, but they work on almost the same principle. A single-cycle generator is powered by a rectified mains voltage, a
pulse transformer with secondary rectifiers is the load, and consumers are powered by them. Depending on the model, the generator may be with external start or with self-excitation. In the key mode, the transistor of the generator works. When it is closed, all the energy goes into the load, and when it is open, energy is stored in the pulse transformer.
The switching power supply converts and stabilizes electric energy from the AC network into the energy necessary to power various equipment. The voltage in the network is variable, which is not suitable for many devices at all and shortens their useful life. The power supply protects the equipment by passing only an acceptable voltage that does not go beyond the specified limits.