ikelectro
Member
Im using a pair of photodiode and infra LED in a circuit. I placed the photo diode opposite of the Infra LED. The distance between them about 2 meter. if a person goes between this pair, then the photodiode will not recieve the light of infrared. and my circuit will give a buzzer tone. but the problem is that the distance 2 meter does not work. if i decrease it 1 meter and more less then it works perfectly. but I want to place them 2 meter away. what should i do now???