Find right IR Sensor - 3.3-5V, 940nm, analog output

Automation and Control Sensors Transducers
1

I’m looking a part for infrared sensor to measure speed of a object passing through 2 gates. I will put an IR sensor and measure time different to measure speed of the object. I also plan to measure angle that object pass the gate which I want output as an analog signal for further calculation on the angle.

I initial thought that TSSP94038 is the right part for my application. I brought for 28 pcs and try to connect to the system. But got various problem.

  1. The datasheet is not clear. I try to connect based on info that I found on the datasheet. I try to connect simple circuit with 2AA power supply and use voltmeter to measure the amount of light detect. But the output voltage is not related to light environment at all.
  2. I think the part might sensitive to handle. However, I got same problem with all 28 pc I purchase. I feel risk if I go forward with the part. So, I also try to find another part that less sensitive for my project as an option.
    I prefer to work with 3.3-5V and 940nm to match with other parts in the system. Any suggest for the part I need to looking for?

Thank you for help :slight_smile:

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2

Greetings,

The part is specifically designed not to respond to ambient light, in order to reject interference from ambient sources. In order to trigger the sensor, an IR source must be modulated at a 38 kHz frequency. This is all mentioned on page 1 of the datasheet.

An IR phototransistor would seem to provide a function closer to what you were expecting.

3

Thank you for your help. I thought that the sensor will detect some infrared from ambient light. It seems the TSSP94038 can screen ambient light pretty well. Now, I can get the input from IR LED, and TSSP94038 can provide correct info from that IR LED light.

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