Description:
HC-SR501 is an automatic control module based on infrared technology. It adopts imported probe design with high sensitivity, strong reliability and voltage working mode. It is widely used in various automatic induction electrical equipment, especially automatic control products powered by dry batteries.
HC-SR501 is an automatic control module based on infrared technology. It adopts imported probe design with high sensitivity, strong reliability and voltage working mode. It is widely used in various automatic induction electrical equipment, especially automatic control products powered by dry batteries.
technical parameter:
1. Working voltage: DC5V to 20V
2. Static power consumption: 65 microamps
3. Level output: high 3. 3V, low 0V
4. Delay time: adjustable (0.3 seconds ^ 10 minutes)
5. Blocking time: 0. 2 seconds
6. Trigger mode: L is not repeatable, H is repeatable, the default value is H
7. Induction range: less than 120 degrees cone angle, within 7 meters
8. Working temperature: -15^ +70 degrees
9. PCB dimensions: 32*24mm, screw hole distance 28mm, screw hole diameter 2mm, induction,
Lens Size: (Diameter): 23mm (Default).
1. Working voltage: DC5V to 20V
2. Static power consumption: 65 microamps
3. Level output: high 3. 3V, low 0V
4. Delay time: adjustable (0.3 seconds ^ 10 minutes)
5. Blocking time: 0. 2 seconds
6. Trigger mode: L is not repeatable, H is repeatable, the default value is H
7. Induction range: less than 120 degrees cone angle, within 7 meters
8. Working temperature: -15^ +70 degrees
9. PCB dimensions: 32*24mm, screw hole distance 28mm, screw hole diameter 2mm, induction,
Lens Size: (Diameter): 23mm (Default).
Application:
Automatic lighting in corridors, corridors, toilets, basements, warehouses, garages, etc., automatic ventilation of exhaust fans and other electrical appliances (incandescent lamps, fluorescent lamps, buzzers, automatic doors, electric fans, dryers and automatic washing machines) Special Applicable to enterprises, hotels, shopping malls, warehouse sensitive areas or security areas and alarm systems. It can also be used for anti-theft purposes.
Automatic lighting in corridors, corridors, toilets, basements, warehouses, garages, etc., automatic ventilation of exhaust fans and other electrical appliances (incandescent lamps, fluorescent lamps, buzzers, automatic doors, electric fans, dryers and automatic washing machines) Special Applicable to enterprises, hotels, shopping malls, warehouse sensitive areas or security areas and alarm systems. It can also be used for anti-theft purposes.
Basic knowledge of pyroelectric sensors and common problems in use
A pyroelectric infrared sensor is a sensor that can detect infrared rays emitted by humans or animals and output electrical signals. As early as 1938, someone proposed to use the pyroelectric effect to detect infrared radiation, but it was not taken seriously. It was not until the 1960s that with the development of laser and infrared technology, the research on the pyroelectric effect was promoted. Application of pyroelectric transistors. Pyroelectric crystals have been widely used in infrared spectrometers, infrared remote sensing and thermal radiation detectors, and they can be used as an ideal detector for infrared lasers. Its target is being widely used in various automation control devices. In addition to being used in the well-known corridor automatic switches and anti-theft alarms, the application prospects in more fields are promising. For example: air conditioners and water dispensers that will automatically stop when the room is empty. A mechanism that automatically shuts down when the TV can determine that no one is watching or that the viewer has fallen asleep. Open the app on the monitor or automatic doorbell_. Combined with a video camera or digital camera to automatically record animal or human activities, etc.... .You can develop more new products according to your own whimsy and combining with other circuits. or automatic control device.
Basic knowledge of pyroelectric sensors
The pyroelectric effect is similar to the piezoelectric effect, and refers to the phenomenon that the surface of the crystal is charged due to changes in temperature. Pyroelectric sensors are temperature-sensitive sensors. It is composed of ceramic oxide or piezoelectric crystal elements, and the two surfaces of the element are made of electricity. When the temperature changes ΔT within the monitoring range of the sensor, the pyroelectric effect will generate a charge ΔQ on the two electrodes, that is, in the A weak voltage ΔV is generated between the two electricity. Due to its high output impedance, there is a FET in the sensor for impedance transformation. The charge ΔQ generated by the pyroelectric effect will be combined with ions in the air and disappear, that is, when the ambient temperature is stable and ΔT=0, the sensor has no output. When the human body enters the detection area, due to the difference between the human body temperature and the ambient temperature, ΔT is generated, and there is ΔT output; if the human body does not move after entering the detection area, the temperature does not change, and the sensor has no output. So this sensor detects human or animal activity sensing. It has been proved by experiments that the sensor does not add an optical lens (also called a Fresnel lens), and its detection distance is less than 2m, and after adding an optical lens, its detection distance can be greater than 7m.
The pyroelectric effect is similar to the piezoelectric effect, and refers to the phenomenon that the surface of the crystal is charged due to changes in temperature. Pyroelectric sensors are temperature-sensitive sensors. It is composed of ceramic oxide or piezoelectric crystal elements, and the two surfaces of the element are made of electricity. When the temperature changes ΔT within the monitoring range of the sensor, the pyroelectric effect will generate a charge ΔQ on the two electrodes, that is, in the A weak voltage ΔV is generated between the two electricity. Due to its high output impedance, there is a FET in the sensor for impedance transformation. The charge ΔQ generated by the pyroelectric effect will be combined with ions in the air and disappear, that is, when the ambient temperature is stable and ΔT=0, the sensor has no output. When the human body enters the detection area, due to the difference between the human body temperature and the ambient temperature, ΔT is generated, and there is ΔT output; if the human body does not move after entering the detection area, the temperature does not change, and the sensor has no output. So this sensor detects human or animal activity sensing. It has been proved by experiments that the sensor does not add an optical lens (also called a Fresnel lens), and its detection distance is less than 2m, and after adding an optical lens, its detection distance can be greater than 7m.
The following points should be paid attention to when using:
1. The DC working voltage meets the value we require. Too high and too low will affect the performance of the module, and the power supply is required to be well regulated and filtered, such as computer USB power supply, mobile phone charger power supply, and older 9V stacked batteries. To meet the working requirements of the module, it is recommended that the customer use the power supply of the transformer and stabilize the voltage by the three-terminal voltage regulator chip, and then filter the power supply through the 220UF and 0.1UF capacitors.
2. When debugging, try to keep the human body away from the sensing area. Sometimes, although the human body is not directly in front of the module, the module can sense when the human body is too close to the module, resulting in continuous output. Also, do not touch the circuit part during debugging, which will also affect the module's work. , The way to compare is to connect the output end to an LED or a multimeter, cover the module with newspaper, leave the room, and wait 2 minutes to see if the module still has output?
3. The module can work normally when it is not connected to the load, but it works disorderly after it is connected to the load. One reason is that the load is relatively power-consuming because the power supply capacity is small, and the voltage fluctuation caused by the load operation causes the module to malfunction. Another reason is that the load There will be interference when the power is on, for example, inductive loads such as relays or electromagnets will generate back electromotive force, and there will be electromagnetic radiation when the 315M launch board is working, which will affect the module. The solutions are as follows: A. Inductance filtering is added to the power supply part. B. The method of using different voltages for the load and the module, for example: the load uses a 24V working voltage, the module uses a 12V working voltage, and is isolated by a three-terminal voltage regulator. C: Use a larger capacity power supply.
3. The module can work normally when it is not connected to the load, but it works disorderly after it is connected to the load. One reason is that the load is relatively power-consuming because the power supply capacity is small, and the voltage fluctuation caused by the load operation causes the module to malfunction. Another reason is that the load There will be interference when the power is on, for example, inductive loads such as relays or electromagnets will generate back electromotive force, and there will be electromagnetic radiation when the 315M launch board is working, which will affect the module. The solutions are as follows: A. Inductance filtering is added to the power supply part. B. The method of using different voltages for the load and the module, for example: the load uses a 24V working voltage, the module uses a 12V working voltage, and is isolated by a three-terminal voltage regulator. C: Use a larger capacity power supply.
4. The human body induction module can only work indoors and the working environment should avoid direct sunlight and strong light. If there is strong radio frequency interference in the working environment, shielding measures can be adopted. In case of strong airflow disturbance, close doors and windows or prevent convection. Try to avoid the induction area facing heat-generating appliances and objects, as well as sundries and clothes that are easily blown by the wind.
5. It is recommended to install the human body induction module in a sealed box, otherwise there may be an output signal all the time.
6. If the detection angle of the human body sensing module is required to be less than 90 degrees, it can be realized by covering the lens with opaque tape or cutting the lens to reduce it.
7. The human body induction module adopts dual-element probe. The movement direction of the human body's hands, feet and head is closely related to the induction sensitivity, and the characteristics of the infrared module determine that the induction distance cannot be controlled.
8. The probe (PIR) in the module can be soldered on the other side of the circuit board. The probe can also be extended with a double-core shielded wire, and the length should be within 20 cm.
Features:
1. Fully automatic induction: when someone enters the induction range, the high level is input, and when the person leaves the induction range, the high level is automatically delayed and turned off. output low level.
2. Photosensitive control (optional): The module has a reserved position, and the photosensitive control can be set, and it will not sense during the day or when the light is strong. Photosensitive control is an optional function, and no photoresistor is installed at the factory. If necessary, please purchase separately 3. Two trigger modes: L is not repeatable, H is repeatable. It can be selected by jumper, the default is H. You can buy the 5539 photoresistor in our store for use.
A. Non-repeatable trigger mode: that is, after the induction output is high, the output will automatically change from high to low as soon as the delay time ends.
B. Repeatable triggering method: that is, after the induction output is high, within the delay time period, if there is a human body moving within its induction range, the output will keep the high level, and the delay will be high until the person leaves. The level changes to a low level (the sensing module will automatically extend a delay time period after detecting each activity of the human body, and the time of the next activity is the starting point of the delay time).
4. With induction blocking time (default setting: 3-4 seconds): After each induction output of the induction module (high level changes to low level), a blocking time can be set immediately, and the induction module can sense within this time period. The device does not receive any induction signals. This function can realize the interval work of (induction output time and blocking time), and can be applied to interval detection products; at the same time, this function can effectively suppress various disturbances generated during the load switching process.
5. Wide working voltage range: default working voltage DC5V to 20V
6. Micro power consumption: quiescent current is 65 microamps, especially suitable for electrical products powered by dry batteries.
7. Output high-level signal: It can be easily connected with various circuits.
2. Photosensitive control (optional): The module has a reserved position, and the photosensitive control can be set, and it will not sense during the day or when the light is strong. Photosensitive control is an optional function, and no photoresistor is installed at the factory. If necessary, please purchase separately 3. Two trigger modes: L is not repeatable, H is repeatable. It can be selected by jumper, the default is H. You can buy the 5539 photoresistor in our store for use.
A. Non-repeatable trigger mode: that is, after the induction output is high, the output will automatically change from high to low as soon as the delay time ends.
B. Repeatable triggering method: that is, after the induction output is high, within the delay time period, if there is a human body moving within its induction range, the output will keep the high level, and the delay will be high until the person leaves. The level changes to a low level (the sensing module will automatically extend a delay time period after detecting each activity of the human body, and the time of the next activity is the starting point of the delay time).
4. With induction blocking time (default setting: 3-4 seconds): After each induction output of the induction module (high level changes to low level), a blocking time can be set immediately, and the induction module can sense within this time period. The device does not receive any induction signals. This function can realize the interval work of (induction output time and blocking time), and can be applied to interval detection products; at the same time, this function can effectively suppress various disturbances generated during the load switching process.
5. Wide working voltage range: default working voltage DC5V to 20V
6. Micro power consumption: quiescent current is 65 microamps, especially suitable for electrical products powered by dry batteries.
7. Output high-level signal: It can be easily connected with various circuits.
Instructions for use:
1 After the induction module is powered on, there is an initialization time of about one minute. During this time, the module will output 0-3 times at intervals, and enter the standby state after one minute.
2. The lens on the surface of the module should be avoided as far as possible from interference sources such as lights, so as to avoid introducing interference signals and cause malfunction; the use environment should be avoided as much as possible.
Avoid flowing wind, which can also interfere with the sensor.
Avoid flowing wind, which can also interfere with the sensor.
3. The induction module adopts a dual-element probe. The window of the probe is a rectangle. The dual-element (A element and B element) are located at both ends of the longer direction. When the human body moves from left to right
Or when walking from right to left, there is a difference in the time and distance when the infrared spectrum reaches the dual element. The larger the difference, the more sensitive the induction.
When the head walks from top to bottom or from bottom to top, the dual element cannot detect the change of the infrared spectral distance, and there is no difference, so the induction is not sensitive or does not work; therefore, the sensor should be installed in the direction of the dual element. It is as parallel as possible to the direction in which the human body is active, so as to ensure that the human body is successively passed through.
Induced by the dual element of the probe. In order to increase the sensing angle range, this module uses a circular lens, which also makes the probe sense on all sides, but the left and right sides are still
However, it has a larger sensing range and stronger sensitivity than the upper and lower directions, so it is still necessary to comply with the above requirements during installation.
Or when walking from right to left, there is a difference in the time and distance when the infrared spectrum reaches the dual element. The larger the difference, the more sensitive the induction.
When the head walks from top to bottom or from bottom to top, the dual element cannot detect the change of the infrared spectral distance, and there is no difference, so the induction is not sensitive or does not work; therefore, the sensor should be installed in the direction of the dual element. It is as parallel as possible to the direction in which the human body is active, so as to ensure that the human body is successively passed through.
Induced by the dual element of the probe. In order to increase the sensing angle range, this module uses a circular lens, which also makes the probe sense on all sides, but the left and right sides are still
However, it has a larger sensing range and stronger sensitivity than the upper and lower directions, so it is still necessary to comply with the above requirements during installation.
Package included:
2/4/6/8/10PCS* module
Note:
Please allow 1-2cm errors due to manual measurement.
Because of the different display of each computer, the pictures may not reflect the actual color of the item.
Because of the different display of each computer, the pictures may not reflect the actual color of the item.
On Oct 23, 2025 at 22:07:06 PDT, seller added the following information:
On Jun 12, 2026 at 14:04:44 PDT, seller added the following information: