In daily life, the remote control is a familiar gadget. Whether it is to control the TV, air conditioner or other electrical appliances, the remote control allows us to operate it easily. So why do some remote controls have a light in front of them, and some remote controls have a long antenna? Why do some TV remote controls have to be pointed at the TV, and some can be controlled with the back facing away? This all depends on the wireless remote control technology it uses.
1. Infrared remote control technology
Infrared remote control is one of the earliest wireless technologies widely used in remote controls. Infrared is an invisible light with a longer wavelength than visible light. There is an infrared light-emitting diode in the remote control, which is the light in front of the remote control that we often see. When we press the button on the remote control, the diode will emit a coded and modulated infrared light pulse. These infrared light pulses carry our operation information to the controlled device to adjust the channel, adjust the volume, or switch the power. However, infrared remote control has certain limitations. It needs to be operated within the line of sight because infrared rays cannot penetrate obstacles such as walls. If something blocks the transmission path of infrared rays, the remote control will fail.
2. Superheterodyne remote control technology
In order to overcome some of the shortcomings of infrared remote control, superheterodyne remote control came into being. It is often presented to us in a form with a long antenna. The transmitting circuit in the remote control transmits the control command through the antenna, and the electrical equipment at the receiving end has a corresponding RF receiving circuit and antenna. After receiving the signal, it is also processed by decoding to realize the control of the electrical appliance. Moreover, since radio frequency signals have strong penetrating power and can pass through obstacles such as walls, radio frequency remote controllers have advantages in terms of distance and obstacle penetration. They are commonly found in remote control cars, remote control airplanes, and some devices in smart home systems (such as smart door locks, smart curtains, etc.). Taking a remote control car as an example, even if the car is in the corner of the room or there are some obstacles blocking the line of sight, it can still be controlled as long as it is within the effective range of the radio frequency signal.
3. Bluetooth remote control technology
Bluetooth remote control is also a common wireless remote control method, especially in some smart devices. The connection between the Bluetooth remote control and the controlled device is established through Bluetooth pairing, which is why our selfie stick remote control needs to be paired with the mobile phone before it can be used. Bluetooth technology has its own advantages. It is relatively secure and can encrypt the transmitted data. Moreover, the Bluetooth remote control can accurately and quickly transmit instructions when the connection is stable.
Now our common TVs, speakers, cameras and other devices are also equipped with Bluetooth remote control functions. When we buy a protocol-adapted remote control for pairing, we can operate freely within the signal range, and there is no need to worry about the need to align the device like infrared remote control. At the same time, it also has good anti-interference ability and can work normally in complex wireless environments.
4. WiFi remote control technology
WiFi remote control technology uses WiFi network for communication and also belongs to the category of radio frequency remote control. After the remote control and the device are connected to the same WiFi network, the control signal sent by the remote control is forwarded through the WiFi router, and the receiving device responds after receiving the signal. WiFi has a fast transmission speed and can carry more complex control instructions and data transmission. It is often used for centralized control of multiple devices in smart home systems, or some remote control devices that require high-speed data transmission. For example, our camera remote control, the camera opens a WiFi local area network, and we use a dedicated mobile phone APP to connect to the camera WiFi, then we can see the camera screen on the mobile phone, and adjust the camera parameters and shutter operation at the same time.
5. ZigBee remote control technology
ZigBee remote control technology usually appears in our lives with WiFi technology. It supports self-organizing networks and has good scalability and stability. It is mainly used in smart home and industrial automation fields. For example, in the sensor network of smart home, ZigBee remote control can be used to control various sensor nodes (such as temperature sensors, humidity sensors, etc.) and actuators (such as smart sockets, electric curtains, etc.) to realize intelligent monitoring and control of the home environment. Its low power consumption allows the device to work for a long time without frequent battery replacement.