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IR Infrared Module Explained: Working Principle, Circuit, and Applications
What is a IR Infrared Transmitter Module?
An infrared transmitter module is a device that converts electrical signals into infrared light for transmission. It is usually composed of infrared emitter diode, drive circuit and related control elements.In many electronic devices and systems, infrared emitting modules play a key role. For example, in common remote control, it is used to send a specific coded infrared signal to achieve remote control of TV, air conditioner and other home appliances.In some security systems, it can also be used for signal transmission and interaction to achieve specific monitoring and alarm functions.
At the same time, the infrared transmitting module is also the “signal transmitter” of the infrared communication system. Its core function is to load the digital command signal output by the microcontroller onto the 38kHz high-frequency carrier, and convert it into infrared light signal through the infrared transmitting tube and radiate it into the space.It is a “golden partner” with the 38kHz digital infrared receiving module. The former is responsible for “encoding and transmitting”, and the latter is responsible for “receiving and decoding”, jointly realizing wireless command transmission between devices.
The core adaptability of the infrared emission module lies in the “38kHz carrier wave” —— only when the carrier frequency of the receiving module is strictly matched can the signal be ensured not to be interfered with and accurately identified. Common infrared emission modules are divided into basic models (only containing emission tubes and driving circuits) and integrated models (with built-in encoding circuits), which are suitable for control requirements of different complexities.
What is the working principle of IR Infrared Transmitter Module?
The infrared transmission process is essentially a three-step linkage of “signal encoding + carrier modulation + photoelectric conversion”, which forms a reverse echo with the decoding process of the receiving module:
1.Instruction input: A single – chip microcomputer (such as Arduino, STM32) outputs an original digital instruction signal (a sequence of high and low voltage levels) according to user operations (such as pressing a button).
2.Carrier modulation: The oscillation circuit inside the module generates a 38kHz high – frequency carrier wave. It superimposes the original instruction signal with the carrier wave (that is, “modulates”), so that the instruction signal has a “unique frequency label” to avoid interference from environmental clutter.
3.Photoelectric conversion: The modulated electrical signal drives an infrared emission tube (usually a gallium arsenide diode). The emission tube converts the electrical signal into an infrared light signal with a frequency of 38kHz and radiates it into space in a diffused manner.
4.Signal transmission: The infrared light signal propagates in space and is captured by the corresponding 38kHz infrared receiving module, thereby completing the subsequent decoding process.
What is the composition of the IR Infrared Transmitter Module?
An infrared emission module is usually made up of an infrared emitting diode, a driving circuit, an encoding circuit (available in some integrated models), and related control components. Among them, the infrared emitting diode is the core photoelectric conversion device. Made of semiconductor materials like gallium arsenide, it can efficiently convert electrical signals into infrared light signals. The driving circuit is responsible for providing a stable current to the emitting tube, ensuring it works in the best condition, and at the same time controlling the emission intensity and frequency. The encoding circuit built into integrated modules can preprocess the original instruction signals to generate encoded signals that meet specific protocols, further improving the accuracy and anti-interference ability of signal transmission. Through precise circuit design and layout, all components work together to achieve stable emission of infrared signals.
Advantages of Capacitive IR Infrared Module
Infrared modules have many significant advantages. First, they have relatively high anti-interference ability. Because they use a specific 38kHz carrier frequency for signal transmission, they can effectively avoid interference from other noise signals in the environment, ensuring the accuracy and stability of signal transmission, and can still work reliably in complex electromagnetic environments. Second, the transmission distance is relatively long. Under certain conditions, infrared light signals can propagate over a long distance, meeting the needs of remote control between devices in different scenarios. Third, the cost is low. The manufacturing process of infrared emission modules is relatively mature, and the cost of raw materials is not high, making their overall price quite affordable and easy to be widely used in various electronic devices. Fourth, the power consumption is relatively low. During operation, infrared emission modules consume less electrical energy, which is crucial for some portable devices that rely on battery power and can effectively extend the use time of the devices. Fifth, installation and use are relatively simple. They usually have standard pins and interfaces, which are convenient to connect with various circuit boards, and can be quickly put into use without complicated debugging processes. These advantages make infrared modules widely used.
What are the application scenarios for the IR Infrared Module？
Thanks to the advantages of infrared modules such as anti-interference ability, support for long-distance transmission, and low cost, infrared modules are applied in a wide range of fields.
- In the field of smart homes, infrared modules are an indispensable part. By integrating infrared emission modules into smart remote controls or smart control centers, users can conveniently control home devices like TVs, air conditioners, and lights remotely, achieving intelligent home management. For example, before going to bed, users only need to send instructions via a mobile app or a smart voice assistant, and the infrared module will send the corresponding control signals to home appliances, making them automatically enter standby or shutdown mode, bringing users a more convenient and comfortable living experience.
- In the field of industrial automation, infrared modules also play an important role. In some scenarios that require wireless command transmission, such as equipment control on automated production lines and goods tracking in warehousing and logistics, infrared modules can serve as a reliable wireless communication method. By installing infrared emission modules and receiving modules on control devices and controlled devices respectively, wireless command transmission between devices can be realized, thereby improving production efficiency and automation levels.
In the field of security monitoring, infrared modules also have broad application prospects. Some security systems use infrared modules for signal transmission and interaction to achieve specific monitoring and alarm functions. For example, in an infrared induction alarm system, when a person or object enters the monitoring area, the infrared emission module will send out specific infrared signals. After being captured by the receiving module, the alarm device will be triggered, thereby promptly reminding users or security personnel to take corresponding measures
IR Infrared Module Transmitter pinout
An infrared emission module usually has three pins: DAT, VCC, and GND.
The DAT pin is a data input pin. It is used to receive digital command signals output by control devices like single-chip microcomputers. This signal will go through the processes of carrier modulation and photoelectric conversion inside the module, and finally be converted into an infrared light signal and emitted.
The VCC pin is the positive power supply pin. It is used to connect to an external power supply and provide a stable working voltage for the infrared emission module, ensuring that the module can work normally.
The GND pin is the power ground pin. It is used to connect to the negative pole of the external power supply to form a complete current loop. In practical applications, correctly connecting these three pins is the key to ensuring the normal operation of the infrared emission module. If the connection error causes the module to fail to transmit infrared signals or operate unstably.
Product Parameter Sheet for IR Infrared Transmitter Module
IR Infrared Transmitter Module | |
Working voltage | 5V |
Signal type | Number type |
Working temperature | -25℃-85℃ |
Infrared central wavelength | 850nm-900nm |
Infrared transmission distance | About 1.3 meters |
Infrared emission angle | About 20° |
Wavelength | 940nm |
Product Parameter Sheet for IR Infrared Receiver Module
IR Infrared Receiver Module | |
Working voltage | 5V |
output form | Digital signal output |
IR Infrared Module datasheet
Here we provide you with the infrared module datasheet for reference：
FAQS
How to tell if an IR transmitter is working?
To determine whether an infrared emission module is working properly, you can test it using the following method.
First, you can use an infrared receiving head for detection. Connect the infrared receiving head to a simple circuit (such as an LED indicator light connected in series with a resistor and then to a power supply). Align the infrared transmitter with the receiver and press the corresponding control button (if there is a button for control). If the LED indicator light connected to the receiving head flashes, it indicates that the infrared emission module can emit infrared signals normally and the module is working properly. If the indicator light doesn’t turn on, there may be a fault in the emission module, meaning it’s not working.
Can infrared detect distance?
Infrared itself can’t directly “detect distance”, but it can achieve distance – related functions through specific designs. In common infrared distance – measuring applications, the “Time of Flight (ToF) method” or “triangulation method” is usually used.
The Time of Flight method calculates the distance by measuring the time it takes for an infrared signal to be sent out, reflected by an object, and then return to the receiving module, combined with the speed of light. The triangulation method uses the positional offset of infrared emission spot on the sensor to calculate the distance through geometric relationship. However, ordinary infrared emission modules (such as those used in remote controls) can only emit signals. They need to be paired with dedicated infrared receiving sensors and algorithms to achieve the distance – measuring function, and the distance – measuring accuracy and range are affected by factors such as ambient light and the reflectivity of objects. If only a basic infrared emission module is used, it can usually only determine “whether there is an obstacle reflecting the signal” and cannot directly obtain an accurate distance value.
