Lexikon Netzteil specifications

Category : Lexicon

A power supply is the assembly in a mains-powered electronic device that is responsible for the power supply. It is necessary because electronic devices usually cannot work directly with the mains voltage. For most electronic devices in the Hi-fi range, DC voltages in the range from 3V to over 100V are required for operation, depending on the case. It is not uncommon for several different DC voltages to be required at the same time. It is the task of the power supply to generate these DC voltages from the AC voltage of 230V available in the power grid.

The simplest and still widely used type of power supply for Hi-Fi devices is based on a mains transformer. In addition, rectification, screening, and possibly voltage regulation are required. The structural simplicity of this variant is contrasted by the size of the transformer, which results, especially in power amplifiers, with their high power requirement. This component consists of an iron core and copper coils, and its size and weight increase with the power requirement. A large part of the weight of a power amplifier thus goes to the account of the mains transformer.

The increasingly popular alternative to this is the switching power supply. With computers, this principle is dominant today. Here, the mains voltage is rectified directly and chopped again with a much higher frequency. Only then comes a transformer, which can be much smaller, lighter and cheaper than the conventional power supply because of the higher frequency. Despite the greater complexity, money can often be saved because of the material savings. However, the chopper generates interference pulses, which must be reduced again by suitable filtering.

For Hi-Fi devices, the power supply is usually integrated into the device. In some cases, however, you can also find external power supplies that are housed in a separate housing and connected to the actual device by cable. For small appliances, this is widespread due to the use of plug-in power supplies. Here, too, you can find both functional principles. An external power supply can make it easier to protect a sensitive electronic circuit from the effects of magnetic stray fields and other interference coming from the power supply, which is primarily caused by the greater distance between the power supply and the device.