BlueCerealBox
- Sep 30, 2014
- 27
- Joined
- Sep 30, 2014
- Messages
- 27
Hi ,
I am currently doing a school project. For one of my subsystems , I am trying to use a IR sensor and emitter to build a distance sensor attached to a buzzer such that the buzzer beeps louder and with a higher frequency the closer an object is to the sensors. However, I am only allowed to use components supplied from my school lab itself.
I am using a TIL38 IR Emitter and a TIL81 IR detector. I have connected the 2 according to the circuit in the image attached to test out the range. When I tried it out , the range was only a few milimeters. I measured the voltage drop across the detector , and realized that it only decreased by a very small amount when the emitter was brought closer , probably about a few hundred μV.
I tried decreasing the resistances in the circuit, which did not help too much. I have researched online and found that one possible method is to set your supply to have a duty cycle of 10% and increase the current supplied , such that it fires short bursts of the max forward current of the emitter ( Which is about 150mA from the datasheet) . So I tried cranking up my voltage supply to 9V and found that the range increases by only a few cm.
Is there any way to further increase this sensing distance? To maybe about 1.5m?
Thank you.
I am currently doing a school project. For one of my subsystems , I am trying to use a IR sensor and emitter to build a distance sensor attached to a buzzer such that the buzzer beeps louder and with a higher frequency the closer an object is to the sensors. However, I am only allowed to use components supplied from my school lab itself.
I am using a TIL38 IR Emitter and a TIL81 IR detector. I have connected the 2 according to the circuit in the image attached to test out the range. When I tried it out , the range was only a few milimeters. I measured the voltage drop across the detector , and realized that it only decreased by a very small amount when the emitter was brought closer , probably about a few hundred μV.
I tried decreasing the resistances in the circuit, which did not help too much. I have researched online and found that one possible method is to set your supply to have a duty cycle of 10% and increase the current supplied , such that it fires short bursts of the max forward current of the emitter ( Which is about 150mA from the datasheet) . So I tried cranking up my voltage supply to 9V and found that the range increases by only a few cm.
Is there any way to further increase this sensing distance? To maybe about 1.5m?
Thank you.