How should the power and power lines in the wireless monitoring system be selected?

The power supply of the camera in the wireless monitoring system is the premise to ensure the normal operation of the wireless monitoring device. How to properly arrange the power of the wireless monitoring system and select the power line is very important in the video monitoring system.

We know that wireless monitoring equipment needs to operate normally and cannot be separated from the normal power supply of the camera in the monitoring system. Then, how to properly arrange the power supply of the wireless monitoring system, how to choose the power line? Let's take a closer look.

First, the power settings

The power setting of the camera is based on whether the camera is on the side of the control unit or a relatively long distance. If it is relatively close, install a high-power DC stabilized power supply directly next to the host, and connect multiple cameras to this power supply. It is more than the sum of the power of the camera.

If the distance is far away, 220V AC power should be distributed to the camera side and then converted to power supply by the regulated power supply. The distance between the 220V AC power line and the video line should be greater than 30 cm to avoid magnetic field interference and affect the image transmission quality.

Second, the choice of power supply

The power line selection must be calculated to obtain a reasonable selection. The working current of the commonly used 12V power supply camera:

Ordinary gun or hemisphere: The working current is about 200~300mA. You can choose 500MA-1A power supply.

Integrated camera: working current is about 350~400mA, you can choose 1A power supply

Small medium-sized infrared camera: 1A power supply with operating current of 600-700mA

Large infrared camera: working current 1000MA-1200mA can choose 2A power supply

Power supply A wireless monitoring system: the camera can be powered separately or in multiple centralized power supply. If multiple cameras are powered centrally, the current required is the sum of multiple camera currents.

Third, the choice of power cord

1, using twisted pair power supply

Category 5 or above unshielded twisted pair cable as the power supply cable for the surveillance camera can simplify wiring, but you must ensure that the power supply passed meets the requirements of the device. For example, the working power of the equipment is 10-12VDC, the current is 500MA, and the internal resistance of the twisted pair is 10Ω/100m (the actual use of oxygen-free copper is 100m is 9.53Ω). If the power supply is 12VDC, consider the distance voltage attenuation. To ensure the normal use of the equipment, the transmission power is within 150 meters.

2, independent RVV line power supply

According to the power of the terminal camera, the power of the general fixed gun machine does not exceed 10W, the infrared gun machine generally does not exceed 20W, and the ball machine is about 35W. From the power point of view, the RVV2*0.5 line is sufficient, and the national standard 0.5 line can carry a load of about 1KW.

For long distances, it is recommended to use a line of not less than 1.0 in consideration of attenuation. If the number of cameras is small (less than 5) and the camera is close to the monitoring host (less than 50 meters), each camera can be independently RVV2 × 0.5 power cable to the monitoring room and powered by a small transformer.

If the number of cameras is large, you should adopt a high-power 12V DC regulated power supply for centralized power supply. In the process of work, the total power of the camera and the voltage drop formed by the transmission line (referred to as "line loss"), the resistance of the copper wire of the specification of 1 m2 per 100 m is 1.8 Ω. For the monitoring of a building, two 2.5-6m2 copper-core double-plastic lines are generally used as the main line of the power supply from the monitoring room to the line well, and along the line well to the line well of each camera floor. For the power supply of each camera on the floor, one RVV2×1 or RVV2×1.5 (if the number of cameras in this layer exceeds 6) can be used to supply power to the camera, or use RVV2×0.5 sheathed wire. Corresponding to power supply.