The relationship between strong current and weak current; The use of strong current.
The difference between strong current and weak current:
Strong current and weak current are relative concepts. Conceptually, the main difference is the different uses, and the relationship between them cannot be simply defined by voltage (if voltage must be specified to distinguish, then more than 36V (human safe voltage) is designated as strong current, and less than 36V (human safe voltage) is designated as weak current. ), there are connections and differences between them. The general principle of distinction is: the processing object of strong electricity is energy (electric power), characterized by high voltage, high current, high power and low frequency, and the main consideration is to reduce loss and improve efficiency. The processing object of weak current is mainly information, that is, information transmission and control, which is characterized by low voltage, low current, low power and high frequency. The main consideration is information transmission. Roughly as follows:
(1) The AC frequency is different.
The frequency of strong electricity is generally 50Hz, which is called "power frequency", which means the frequency of industrial electricity. The frequency of weak current is often high frequency or ultra-high frequency, which is measured by KHz and MHz.
(2) Different transmission modes
Strong electricity is transmitted through transmission lines, and weak electricity is transmitted through wires or wireless. Radio is transmitted by electromagnetic waves.
(3) Power, voltage and current are different.
There are also high frequency (hundreds of KHz) and intermediate frequency devices in high voltage, but the voltage is higher and the current is larger. Due to the development of modern technology, weak current has penetrated into high voltage fields, such as power electronic devices and wireless remote control. But these can only be regarded as the weak current control part of high voltage, which is different from charged high voltage.
According to the basic principle that weak electricity conducts signals and strong electricity conducts electric energy, we can easily distinguish strong electricity from weak electricity. For example, although electric shavers, flashlights, etc. Only two dry batteries (3V) are used, so it can't be considered as weak current because the voltage and current of the electrical appliance are small, because it conducts electric energy instead of signals, so it should belong to strong current.
The relationship between strong current and weak current; The use of strong current.
High pressure use:
Strong electricity generally refers to power supply and distribution systems such as mains lighting systems, including air conditioning lines, lighting lines, socket lines, power lines and high-voltage lines. There are mainly two kinds of weak current: one is low-voltage electric energy such as safe voltage grade and control voltage specified by the state, which is divided into AC and DC, such as 24V DC control power supply or emergency lighting standby power supply. The other is the information source containing voice, image, data and other information, such as audio, video, network and telephone lines, etc. The DC voltage is generally within 36V. Telephone, computer, TV signal input (cable TV line), audio equipment (output line), broadcasting system, building automation (such as access control and security) and other electrical appliances are all weak current electrical equipment.
This is what I introduced to you today. I believe that friends have a certain understanding. I hope this article can help you. You can also log in to view and subscribe to more related content and information.