RF Remote Control is a remote control device that uses radio signals to control various institutions in the distance. After these signals are received by the remote receiving device, they can instruct or drive various other corresponding mechanical or electronic devices to complete various operations, such as closing the circuit, moving the handle, and turning on the motor, and then these machines can perform the required operations. As a kind of remote control that complements infrared remote control, it has been widely used in garage door, electric gate, barrier remote control, anti-theft alarm, industrial control and wireless smart home.
Commonly used radio remote control systems are generally divided into two parts: transmitting and receiving.
(1) The transmitting part is generally divided into two types, namely the remote control and the transmitting module. The remote control and the remote control module are based on the way of use. The remote control can be used as a whole machine independently, and the external lead wires have wiring pile heads. ; The remote control module is used as a component in the circuit, and it is applied according to its pin definition. The advantage of using the remote control module is that it can be seamlessly connected with the application circuit, small in size, low in price, and make the best use of it, but the user must Really understand the circuit principle, otherwise it is convenient to use the remote control.
2) Generally speaking, the receiving part is divided into two types, namely superheterodyne and super regenerative receiving mode. The super regenerative demodulation circuit is also called the super regenerative detection circuit, which is actually a regenerative detection circuit that works under intermittent oscillation. . The superheterodyne demodulation circuit is the same as the superheterodyne radio. It is to set a local oscillator circuit to generate an oscillating signal, which is mixed with the received carrier frequency signal to obtain an intermediate frequency (generally 465kHz) signal, which is amplified and amplified by the intermediate frequency. Detect and demodulate the data signal. Since the carrier frequency is fixed, its circuit is simpler than the radio. The superheterodyne receiver is stable, high sensitivity, and relatively good anti-interference ability; the super regenerative receiver is small in size and cheap.
The carrier frequency commonly used for radio remote control is 315mHz or 433mHz. The remote control uses an open frequency band specified by the state. In this frequency band, the transmission power is less than 10mW, the coverage area is less than 100m or does not exceed the range of the unit. The management committee" approves and uses it freely. my country’s open frequency band is regulated as 315mHz, while European and American countries stipulate it as 433mHz. Therefore, products exported to these countries should use 433mHz remote control.
There are two types of coding methods commonly used in radio remote control, namely, fixed code and rolling code. Rolling code is an upgraded product of fixed code. Rolling coding is used where confidentiality is required.
The difference between IR and RF Remote Control (The difference between IR and RF Remote Control). Infrared remote control and wireless remote control are for different carriers. Infrared remote control uses infrared to transmit control signals. Its characteristics are It is directional, can not be blocked, the distance is generally no more than 7 meters, and is not subject to electromagnetic interference. The TV remote control is an infrared remote control; the radio remote control uses radio waves to transmit control signals. It is characterized by non-directional, It can be controlled without "face to face", the distance is long (up to tens of meters, or even several kilometers), and it is susceptible to electromagnetic interference. In fields that require long-distance penetration or non-directional control, such as industrial control, etc., it is easier to use a radio remote control.
