Ir Sensor Circuit Symbol. This sensor is analogous to human s visionary. The passive infrared sensor consists of three pins as shown below.
Based on the intensity of the reception by the ir receiver the output of the sensor is defined. This circuit will use an op amp to amplify the photodiodes signal a buzzer is connected to the output of the op amp but that can be modified and replaced with another component circuit. The quantum ir sensor depends on the wavelength and these sensors include high response and detection time.
Now you understand how the ir led and photodiode works together as a sensor we are going to transform the previous circuit into an alarm circuit.
Here in this infrared sensor the lm358 ic is used as a comparator for comparing the sensor and reference voltage. These sensors need regular cooling for specific measurements. Ir sensor object detection. Pin 1 is vcc which is connected positive 5v supply.
