IR – Infrared Sensor

It works fine with 3.3 to 5V levels. Upon hindrance/reflectance, the output pin gives out a digital signal (a low-level signal). The onboard preset helps to fine-tune the range of operation, the effective distance range is 2cm to 30cm. It consists of three pins i.e., VCC, GND, and I/O pins.

Infrared Sensor

The IR sensor or infrared is one kind of electronic component, used to detect specific characteristics in its surrounding through emitting or detecting Infrared radiation. These sensors can also be used to detect or measure the heat of a target. In many electronic devices, the IR sensor circuit is a very essential module. This kind of sensor is similar to human’s visionary senses to detect obstacles.

Photodiode Receiver

Photodiode is a semiconductor which has a P-N junction, operated in Reverse Bias, means it start conducting the current in reverse direction when Light falls on it, and the amount of current flow is proportional to the amount of Light. This property makes it useful for Infrared detection. Photodiode looks like a LED, with a black color coating on its outer side, Black color absorbs the highest amount of light.

LM358 

LM358 is an Operational Amplifier (Op-Amp) is used as voltage comparator in the IR sensor. the comparator will compare the threshold voltage set using the preset (pin2) and the photodiode’s series resistor voltage (pin3).

Photodiode’s series resistor voltage drop > Threshold voltage = Op-amp output is High

Photodiode’s series resistor voltage drop < Threshold voltage = Op-amp output is Low

When Op-amp’s output is high the LED at the Op-amp output terminal turns ON (Indicating the detection of Object).

1. Comparator chip: LM393
2. 3mm screw holes for easy mounting
3. Detection distance: 2 ~ 30cm
4. Detection angle: 35 °
5. The Infrared sensor module consists mainly of the IR Transmitter and Receiver, Op-amp, Variable Resistor (Trimmer pot), output LED along with few resistors.
6. Store – Shokitech