Distinguish between infrared emission tubes and receiving tubes from their appearance:

Infrared emission tube: In general, we can distinguish between infrared emission tubes and infrared receiver tubes from their appearance. Infrared emission tubes are generally transparent and can clearly see the internal structure.

The internal structure of infrared emission tubes is basically the same as that of light-emitting diodes, but the difference lies in the different internal materials. And we don't need to use it to know its positive and negative poles, usually the positive pole, and the short leg is the negative pole.

Infrared receiver tube: An infrared receiver tube is an electronic component that converts infrared light signals into electrical signals. Most infrared receiver tubes are encapsulated in black opaque resin.

The infrared receiving tube includes an infrared receiving diode and an infrared receiving transistor. The two pins are infrared receiving diodes, with the long pin being the positive pole and the short pin being the negative pole. The tripod is an infrared transistor, divided into NPN and PNP types.

1. Different appearance

From the appearance, there is a difference between infrared emitting tubes and receiving tubes. The generally transparent one is the transmitting tube, while the opaque one is the infrared receiving tube. Due to the need to consider different angles of signal transmission in the transmitter, transparent colloids are used as packaging in the design. And in order to better resist light interference, it is generally designed as a black colloid packaging.

Infrared receiver tube

2. Adopting the three meter measurement method

If the tube of the infrared receiving tube is also a transparent colloid, it needs to be measured and judged by an instrument. It is recommended to use a multimeter for measurement and judgment.

A multimeter can be used to measure the Rxlk resistance value of a 500 type resistance tester or other pointer type multimeter to identify the infrared pair tube by measuring the interpole resistance of the infrared pair tube.

Criterion 1: When there is no light at the end of the infrared tube, changing the metering point results in a small forward resistance of the transmitting tube and a large reverse resistance. If the emission tube is black, when the emission tube is black, the emission tube is black. Black (long needle). Both forward and reverse resistors are receiver tubes.

Criterion 2: When the black probe is connected to the negative electrode (short needle), the resistance of the transmitting tube is relatively high. The pointer of the multimeter changes with light intensity, and when the pointer swings to the receiving tube, the resistance of the receiving tube is small.

Attention:

When the black lead is connected to the positive pole and the red lead is connected to the negative pole, measure the resistance of the positive pole.

A high resistance means that the pointer of the multimeter is basically stationary.

How to distinguish between infrared transmitting tubes and infrared receiving tubes

Infrared emission tubes generally fall into the following categories:

The main peak wavelengths are: 850nm, 870nm, 880nm, 940nm, 980nm

Power: 850nm>880nm>940nm

Price: 850nm>880nm>940nm

At present, 850nm and 940nm infrared emission tubes are mainly used in the market. Due to the higher power emitted by 850nm and the longer irradiation distance, it is mainly used for infrared monitoring equipment; And 940nm is mainly used for infrared remote control of household appliances.

The energy distribution of a luminous body or object measured on a spectrometer, and the wavelength corresponding to its peak position, is called the peak wavelength λ P Radiant intensity: POWER (unit: mW/sr) is used to indicate the infrared energy radiated by infrared light-emitting diodes (IRLEDs).

Radiant intensity is proportional to input current (If), and emission distance is proportional to Radiant intensity. MW/sr: the unit representing the infrared Radiant intensity, which is the infrared light emitted by the emission tube, and the light power radiated from the Solid angle (sr)

Half power angle: 2 θ 1/2 refers to the included angle between the upper, lower or left and right sides of the transmitting tube when the infrared radiation intensity of the transmitting tube is 50% of the maximum Radiant intensity of the element, which is called the half power angle.

People tend to collectively refer to infrared emission tubes and infrared reception tubes as infrared tubes. The shape of the infrared pair tube is similar to that of a regular circular light-emitting diode. For people who have just come into contact with infrared tubes, it is difficult to distinguish between transmitting tubes and receiving tubes.