Jul 06, 2023
Solar wall lamps integrated with human body induction function are mainly equipped with human body sensors (core for motion/ presence detection) and light sensors (auxiliary for ambient light detection), with PIR (Passive Infrared) sensors being the most mainstream human body induction component for such lamps.
Solar wall lamp is an outdoor lamp powered by solar energy, which has the following characteristics and advantages:
1. Core Sensor Types & Their Application Features
Main Human Body Sensor
PIR Passive Infrared Sensor: The most commonly used type for solar wall lamps (cost-effective, low power consumption, suitable for low-power solar systems). It only detects the infrared radiation emitted by the human body (36~37℃) and the temperature change of the induction area, triggering the lamp to turn on when a moving human body is detected.
Microwave Radar Sensor (supplementary): A small number of high-end solar wall lamps use it (or PIR+radar dual induction). It detects moving objects through microwave reflection, with stronger anti-interference, but higher power consumption (needs to match high-capacity solar batteries).
Ultrasonic Sensor: Rarely used for solar wall lamps (high power consumption, easy to be disturbed by environmental noise).
Auxiliary Light Sensor
Nearly all solar wall lamps are equipped with photoresistors/photosensitive diodes/photosensitive transistors (low cost, miniaturized). It is responsible for detecting ambient light intensity and realizing light control linkage (the human body sensor only works in dark environments to avoid the lamp turning on in daylight and wasting solar power).
2. Core Working Principles (Dual-sensor Linkage Logic)
The sensors of solar wall lamps work in a cooperative mode, and the lamp is triggered to turn on only when two conditions are met at the same time:
The light sensor detects that the ambient light intensity is lower than the set threshold (e.g., <10lux, dark night/indoor shade);
The human body sensor (PIR/radar) detects a moving human body/presence in the induction range.
After the human body leaves the induction area, the sensor will trigger the lamp to turn off automatically after a set delay time (to avoid frequent on/off).
3. Key Technical Parameters (Critical for Product Performance)
These parameters directly determine the use experience of solar wall lamps and need to be matched with the lamp’s power, solar panel and battery capacity:
Induction Distance: PIR sensors for solar wall lamps are usually 3~8m (adjustable for partial models); radar sensors can reach 5~12m (longer distance but higher power consumption).
Induction Angle: 120°~180° (wide-angle design is more suitable for wall-mounted use, covering corridors, courtyards, doorways).
Delay Off Time: 10s~5min (adjustable, the most common is 30s~1min for solar lamps to save power).
Light Control Threshold: 5~20lux (factory calibrated, some models support manual adjustment; lower threshold = the lamp turns on later at night).
Working Voltage & Power Consumption: Matched with solar wall lamp’s DC low voltage (3.7V/6V/12V); standby current of PIR sensor is <10μA (critical for solar products—low standby power ensures the battery does not run out in standby state).
Temperature Range: -20℃~60℃ (adaptive to outdoor high/low temperature, the core parameter for outdoor solar lamp sensors).
4. Environmental Factors Affecting Sensor Performance
Solar wall lamps are mostly used outdoors, and the sensor’s stability is greatly affected by the environment—key influencing factors include:
Temperature: PIR sensors have a temperature compensation design, but extreme high temperature (>50℃) will reduce induction sensitivity; low temperature (<-10℃) will slightly increase power consumption.
Heat Source Interference: PIR sensors are sensitive to temperature changes—avoid installing the lamp facing direct heat sources (air conditioners, heaters, street lamps, sunlight reflection) to prevent false triggering (the lamp turns on without human body).
Obstacle Blockage: Opaque objects (walls, glass, thick plastic) will block infrared/microwave signals; the sensor’s induction window can only be covered with transparent PC/PMMA materials (special infrared-transparent lens for PIR).
Humidity & Dust: Outdoor rain, fog, dust accumulation on the sensor lens will reduce induction sensitivity; high humidity (e.g., coastal areas) requires the sensor to have IP65+ waterproof and dustproof performance.
Strong Light Interference: Direct sunlight/strong artificial light will cause the light sensor to misjudge the ambient light intensity, leading to the human body sensor being in a closed state for a long time.
Battery capacity
3.2v 8000mAh
solar panel
5v/5w
LED chips
2835 30pces
5. Matching Requirements with Solar Wall Lamp System
Sensors are the "intelligent core" of solar wall lamps, and their performance must be highly matched with the solar power supply system (the most important feature distinguishing them from ordinary wall lamp sensors):
Ultra-low Standby Power Consumption: The sensor must be in low-power standby mode during the day (no human body induction + high ambient light) to avoid consuming the solar battery’s stored power.
Battery Voltage Adaptation: The sensor must support normal work under the fluctuating voltage of solar lithium batteries (3.2V~4.2V for single-cell lithium iron phosphate/lithium ion batteries); over-voltage/under-voltage protection is required.
Charging & Induction Linkage: High-quality solar wall lamps will set the sensor to a low-sensitivity state when the battery power is low (<20%) to prioritize battery protection and avoid over-discharge.
Load Matching: The sensor’s output current must match the lamp’s load (LED lamp beads of solar wall lamps are usually 0.5~3A); the sensor needs to drive the LED drive module stably without strobing.
6. Installation & Calibration Tips for Sensor-equipped Solar Wall Lamps
The installation position and angle directly affect the sensor’s induction effect—key points for on-site construction:
Installation Height: 1.8~2.5m (the optimal height for PIR sensors to detect human body infrared radiation; too high/low will reduce the induction distance and angle).
Induction Direction: The sensor lens should face the human body activity area (corridors, doorways, walkways); avoid facing the sky, walls or closed corners.
Avoid Interference Sources: Install at least 1.5m away from heat sources (air conditioners, chimneys) and strong light sources (street lamps, neon lights); the solar panel of the wall lamp should not block the sensor lens.
Calibration After Installation: Power on the lamp and wait for 1~2 minutes (sensor self-calibration); test the induction effect by moving in the induction range, and adjust the delay time/light control threshold if necessary (for adjustable models).
7. Common Sensor Faults & Daily Maintenance Methods
Most malfunctions of solar wall lamps are related to sensors—common faults and simple solutions (no professional maintenance required):
Common Faults
Causes
Solutions
The lamp does not turn on when a human body approaches (in dark environment)
1. Sensor lens is covered with dust/dirt;
2. Installation height/angle is incorrect;
3. Sensor is damaged by water/voltage instability.
1. Wipe the lens with a dry soft cloth;
2. Adjust the installation height/angle;
3. Replace the sensor module (integrated design for most lamps—replace the whole lamp).
The lamp turns on randomly (no human body, dark environment)
1. Close to heat sources/strong light interference;
2. Sensor temperature compensation failure;
3. Battery power is too low.
1. Reinstall the lamp away from interference sources;
2. Reset the lamp (power off and restart);
3. Charge the solar battery fully.
The lamp turns off immediately after the human body leaves (no delay)
1. Delay time is set to 0s;
2. Sensor’s delay circuit is faulty.
1. Adjust the delay time (for adjustable models);
2. Replace the sensor/lamp.
The lamp is always on (day and night)
1. Light sensor is covered/damaged;
2. Sensor linkage logic failure.
1. Clean the light sensor lens;
2. Reset/replace the lamp.
Daily Maintenance: Wipe the sensor lens with a dry soft cloth every 1~3 months (remove dust/rain stains); check the waterproof seal of the sensor module (outdoor use) to avoid water ingress; avoid hitting the sensor part with hard objects (the PIR lens is fragile).
8. Selection Criteria for Solar Wall Lamp Sensors (For Product R&D/Purchase)
When selecting or developing solar wall lamps, the sensor is a key selection index—priority should be given to the following points:
Stability & Anti-interference: Choose PIR sensors with digital temperature compensation (stronger adaptability to outdoor temperature changes) and anti-strong light design.
Ultra-low Power Consumption: Standby current <10μA, working current <50mA (to match the small-capacity solar battery of wall lamps).
Waterproof & Dustproof: The sensor module has IP65+ waterproof performance (consistent with the whole lamp’s protection level) for outdoor use.
Integrated Design: Choose sensors integrated with light control and human body induction (simpler circuit, lower failure rate, more suitable for miniaturized solar wall lamps).
Brand Reliability: Select mainstream industrial sensor brands (e.g., Panasonic, Omron, or cost-effective domestic brands) to avoid inferior sensors with large parameter errors and short service life.
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