HC-SR501 Human Presence Sensor Human Infrared

The HC-SR501 is an infrared-based automatic control module with high sensitivity, strong reliability, and ultra-low voltage operation. It is widely used in various automatic sensing electrical equipment, especially battery-powered automatic control products.

Features
1. Fully Automatic Sensing: A high-level output is triggered when a person enters the sensing range; the high-level output automatically shuts off after a delay and returns to a low-level output when the person leaves the sensing range.
2. Photosensitive Control (Optional, not set at the factory): Photosensitive control can be set to disable sensing during the day or in strong light.
3. Temperature Compensation (Optional, not set at the factory): In summer, when the ambient temperature rises to 30-32℃, the detection distance slightly shortens; temperature compensation can provide some performance compensation.
4. Two Triggering Methods: (Jumper selectable)
a. Non-repeatable triggering: After the sensor outputs a high level, the output will automatically change from high to low after the delay period ends.
b. Repeatable triggering: After the sensor outputs a high level, if a person moves within the sensing range during the delay period, the output will remain high until the person leaves, at which point it will change from high to low after a further delay. (The sensor module automatically extends the delay period after detecting each human movement, with the time of the last movement as the starting point of the delay.)
5. Sensor Blocking Time (Default setting: 2.5S Blocking Time): After each sensor output (high level to low level), a blocking period can be set immediately afterward. During this period, the sensor does not accept any sensing signals.This function allows for interval operation of both the "sensing output time" and the "blocking time," applicable to interval detection products. This function also effectively suppresses various interferences generated during load switching. (This time can be set from a fraction of a second to tens of seconds.) 6. Wide operating voltage range: Default operating voltage DC 4.8V~20V.
7. Low power consumption: Static current <50 microamps, particularly suitable for battery-powered automatic control products.
8. High-level output signal: Allows easy integration with various circuits.

Note: Adjusting the distance potentiometer clockwise increases the sensing distance (approximately 7 meters), and counterclockwise decreases the sensing distance (approximately 3 meters).
Adjusting the delay potentiometer clockwise lengthens the sensing delay (approximately 300 seconds), and counterclockwise shortens the sensing delay (approximately 5 seconds).

Instructions for Use
1. After powering on, the sensor module has an initialization period of approximately one minute. During this period, the module will output 0-3 times intermittently. After one minute, it enters standby mode.
2. Avoid direct sunlight or other sources of interference onto the lens surface of the module to prevent interference signals and malfunctions. Avoid windy environments, as wind can also interfere with the sensor.
3. The sensing module uses a dual-element probe with a rectangular window. The two elements (element A and element B) are located at opposite ends of the longer direction. When a person walks from left to right or right to left, there is a difference in the time and distance at which the infrared spectrum reaches the two elements. The larger the difference, the more sensitive the sensing. When a person walks towards the probe from the front, from top to bottom, or from bottom to top, the dual elements cannot detect the change in infrared spectral distance, resulting in no difference and therefore insensitivity or inoperability. Therefore, when installing the sensor, the direction of the dual elements should be as parallel as possible to the direction of the most frequent human movement to ensure that the person is sensed by the dual elements sequentially as they pass by. To increase the sensing angle range, this module uses a circular lens, allowing the probe to sense from all four sides. However, the sensing range and sensitivity on the left and right sides are still larger than those on the top and bottom. Installation should still adhere to the above requirements as much as possible.

Parameters
Operating Voltage Range: DC 4.8~20V
Quiet Current: <50uA
Level Output: High 3.3V / Low 0V
Trigger Method: L Non-repeatable trigger / H Repeatable trigger (default repeatable trigger)
Delay Time: 0.5-200S (adjustable), range from a fraction of a second to tens of minutes
Block Time: 2.5S (default), range from a fraction of a second to tens of seconds
Circuit Board Dimensions: 32mm*24mm
Sensing Angle: <100-degree cone angle
Operating Temperature: -15-+70 degrees Celsius
Sensing Lens Size: Diameter: 23mm