Security monitoring What are the three modes of power supply
Security monitoring equipment power supply is a concern of security engineering companies. In recent years, almost all security monitoring manufacturers are pushing PoE network cable for power supply, but why do security monitoring equipment still rely on strong current and centralized power supply? Let's first understand the three modes of power supply for security monitoring.
Security monitoring power supply modes mainly include: point-to-point independent power supply (commonly known as deploying strong current, selecting power adapter for power supply), centralized power supply, PoE network cable power supply.
Point to point independent power supply mode
Point to point independent power supply means that 220V AC power is directly led from the monitoring room, and wires/combination wires (network wires+wires) are used in the middle, and then video camera A separate DC12/24V power adapter is connected to the side, and then connected to the surveillance camera. Each power supply only provides power for one camera.
What are the three modes of security monitoring power supply? How to choose the scheme?
1. Advantages of independent power supply
Simple maintenance and replacement: in case of camera failure, it can quickly troubleshoot and repair or replace the equipment;
Long power supply distance: using strong current 220V output, it can be cascaded, with long power supply distance and basically no loss.
2. Insufficient independent power supply
The cost is relatively high: the cost of deploying multiple independent monitoring power adapters is higher than that of centralized power supply with the same power output;
Weak safety and stability: strong electricity is more dangerous than weak electricity, and the aging of lines+mouse damage are likely to lead to short circuit and even fire. And the distance between the independent monitoring power supply and the camera is mostly in the outdoor environment, which is vulnerable to the impact of external damage factors such as lightning strikes.
Centralized power supply mode
Centralized power supply means that a 12/24V 4A centralized power supply is connected to the 220V power supply, and then 2 * 1.0 red and black power lines/combination lines are connected to the camera respectively, without the need to install additional power adapters in the front of the camera. Compared with the point-to-point independent power supply mode, the biggest difference of this mode is that one power supply can provide power for multiple cameras.
What are the three modes of security monitoring power supply? How to choose the scheme?
1. Advantages of centralized power supply
Low cost: thanks to the high cost performance of centralized power supply, the cost of power supply system adopting centralized power supply mode is low;
Simple maintenance: centralized power supply mode is adopted, which is convenient for line laying, construction and management.
2. Disadvantages of centralized power supply
The early deployment is complex: the power of centralized power supply is not simply the sum of the power of all surveillance cameras, but also the power loss. The wires on the market are uneven, so this method requires high requirements for engineers.
System risk exists: if not adopted UPS Power supply, once the power supply system in the centralized power supply mode has problems, the entire monitoring system will not work normally and fall into a paralyzed state.
PoE network cable power supply mode
PoE network cable power supply refers to the mode that the front-end network camera can be powered and data can be transmitted through one network cable without any change to the existing Ethernet cabling architecture, commonly known as network cable power supply. The current mainstream PoE network cable power supply modes in the market mainly include the following two types.
1. 12/24V passive PoE network cable power supply
advantage:
Low cost: generally, 45+78 line sequence of network cable is used for power supply. With the corresponding voltage transfer separator, many front-end devices that do not support network cable power supply can solve the power supply and data transmission problems with only one network cable.
Disadvantages:
The deployment is complex: it is necessary to know the voltage of the powered equipment and select the corresponding Switch It is not recommended to choose 12V passive power supply switch and straight through separator, because when transmitting the same power, the transmission distance of 12V passive power supply switch is only 30 meters, which will lead to insufficient voltage and serious power loss. 24V passive power supply switch can be used for power supply of equipment below 15W, and the distance can reach 100 meters.
Poor security and stability: Most 24V/12V network cable power supply switches on the market are directly supplied, and the power supply is basically inferior without 3C certification, and the switch port has no lightning protection, which brings potential safety hazards to the subsequent use of the product.
In response to the above problems, UTP launched a highly reliable 24V PoE power supply switch. The whole series of products use 3C certified power supply with 6KV protection. All ports of the switch support 6KV lightning protection and three gear dial power switch control. With the Youtepu 24V to 12V separator, it really solves the problem of complex deployment of front-end equipment such as non PoE cameras, access control, network bridges, etc. during project deployment and high cost of power supply.
2. 44-57V standard PoE network cable power supply
advantage:
Strong security compatibility: PSE chip is included, and power is supplied only when standard equipment is detected to be connected. PC、 Non standard PD devices such as switches and NVRs can also be connected freely without burning the device; Meet af/at standard, plug and play.
Disadvantages:
The cost is relatively high: the front-end equipment needs to add a PD chip, and the switch needs to add a PSE chip, so the overall product price is relatively high.
Selection of power supply mode for security monitoring
The specific selection of power supply mode depends on the customer's installation environment and actual needs. Suggestions are as follows:
1. If the on-site strong current deployment is ready, the power supply is convenient and the cost is low. Then select point-to-point power adapter or centralized power+common switch to solve the data transmission and power supply problems of front-end equipment.
2. If the front-end equipment does not support the terminal equipment powered by the network cable, it is troublesome and costly to deploy strong electricity. Then selecting the corresponding step-down separator+24V non-standard network cable power supply switch is a cost-effective choice to solve the data transmission and power supply problems of front-end equipment.
3. If the front-end device is a terminal device that supports network cable power supply, it is troublesome and costly to deploy strong electricity. Then selecting the corresponding 44-57V standard PoE network cable for power supply is a cost-effective choice to solve the data transmission and power supply problems of front-end devices.
PoE network cable power supply prospect is promising
It can be seen from the increasing number of PoE equipment displayed by large and medium-sized enterprises in the security exhibition in recent two years that PoE network cable power supply technology is getting ready. However, because cameras produced by several domestic security giants do not support PoE power supply and there is a price difference between PoE power supply and PoE power supply, PoE power supply switches have high cost, uneven equipment quality, poor lightning protection performance of some manufacturers' equipment, high power consumption, poor heat dissipation and other reasons, which lead to the fact that engineering friends think PoE equipment is unreliable, and prefer to choose independent power supply or centralized power supply to solve the power supply problem of monitoring camera heads, making PoE power supply not become mainstream.
It is believed that as the price of products supporting PoE power supply equipment in the front end gradually decreases, more and more manufacturers launch cost-effective PoE network cable power supply switches, and the labor cost of the project gradually increases, the engineering companies begin to realize the application value of PoE separator and PoE power supply switches, PoE power supply technology will eventually become the mainstream of security monitoring power supply.
