June 09, 2023
There are many types of working voltage for security cameras: 220V (used in special industries), 12V and 5V for card machines, but 12V is most widely used. There are four main ways to power ordinary security cameras.
1. Autonomous power supply
The line uses 220V mains power for camera, and then uses a small 12V 2A power supply to convert 220V mains power to 12V; Hidden danger.
2. Centralized power supply that uses a centralized 12V power supply to power front camera.
The advantage of this power supply method is that it is safe and easy to manage. Avoid phenomenon of paralysis of monitoring system
If there is a problem with power supply system in centralized power supply mode and without use of a UPS, entire monitoring system will not work normally and will be paralyzed. In self-powered mode, due to a power failure of video surveillance system, one or more cameras cannot work, which avoids paralysis of monitoring system.
The disadvantage is that line should not be too long. Depending on thickness of line, try not to exceed 50 meters. If line is too long, loss will be large and voltage will be insufficient, causing camera to malfunction due to insufficient power supply such as infrared radiation, which will affect life of camera.
How to choose an autonomous power supply and a centralized power supply
The advantages and disadvantages of autonomous and centralized power supply modes are approximately same as indicated above. The choice depends on actual installation environment and customer requirements. Generally speaking, an independent power supply is suitable for monitoring systems with less than 4 channels. For monitoring systems from 4 to 16 channels, if distance is relatively close, it is recommended to select centralized power mode. Monitoring of more than 16 channels can be combined with multiple centralized power supplies, provided pre-configuration has to be done correctly.
3. Standard POE power supply
A standard POE switch has a POE control chip inside. It has a pre-power detection function. When device is connected, POE switch will send a signal to network to determine if IP terminal in network supports POE. If powered device supports it, POE switch will supply power to it. If it does not support POE, switch will not supply power to it, which has a protective effect on IP terminal.
Standard POE power supply only needs one network cable for signal transmission and power supply, which saves wires, and transmission distance can reach 150 meters.
4. Non-standard POE power supply
Compared with standard POE, non-standard POE usually outputs 24V, 15V, etc. There is no POE control chip inside non-standard POE switch, it directly transmits power through an empty pair of lines in 45, 78 network cable for power transmission, no detection step, no matterWhether IP terminal supports POE or not, it will supply power to it, if IP terminal does not support 24V POE power supply, it is very possible to rudely use spare line in network cable as a power line Burn the network port.
