As designers and constructors in the security industry, they often overlook the important part that has a significant impact on system stability - the security power supply. As the "heart" of the power supply safety system, any safety equipment cannot do without the security power supply. The safety and reliability of the security power supply are important conditions to ensure the normal operation of the communication system.
Security power supply classification:
1、 Linear regulated security power supply:
1. Linear regulated power supply: According to convention, linear regulated power supply can be divided into two types: transformer type regulated power supply and switch type linear regulated power supply.
1.1 Transformer type linear regulated power supply: Its common feature is that the power device regulator operates in the linear region, regulating the voltage drop between the tubes to stabilize the output. Due to the large static loss of the regulating tubes, a large heat sink needs to be installed to dissipate heat. Moreover, because the transformer operates at the power frequency (50Hz) and is relatively heavy, this type of power supply has high stability.
1.2. Open linear regulated power supply: Different from transformer type linear regulated power supply, it is a switch linear regulated power supply. Its circuit types mainly include single end flyback, single forward, half bridge, push pull, and omnidirectional bridge. The fundamental difference between it and linear power supply is that the transformer does not work at the power frequency, but at 10 kHz to 10 MHz, and the function of the electronic tube is not to work in the saturation and cut-off regions, It works in the on/off state: hence the name switching power supply, which has the advantages of small size, light weight, and stability and reliability; The disadvantage is that compared to transformer type linear regulated power supply, the ripple is larger, and the current is W1% Vo (RP), which can reach below 10 mV (P-P).
2、 AC security power supply: generally refers to the voltage or current that changes periodically in size and direction at any time. The standard for AC power supply in China is 220V 50. The plugs and sockets used for power supply are also different, and the forms of AC power supply that change over time can be diverse. Different forms of AC power have different purposes and functions, and sinusoidal AC power is widely used.
3、 Inverter security power supply: generally refers to a device that converts low voltage direct current into high voltage or low voltage alternating current. Generally, inverter power supplies come with their own batteries. The UPS power supply purchased from the computer market is one of the inverter power supplies, but the battery is small, so the computer can only work for a few or ten minutes after a power outage. It is mainly used to continue supplying power to the computer in the event of a sudden power outage, and has time to save unsaved data.