Hi There
I am currently having a bit of a fight with an IR photo-transistor.
The schematic is simply a 555 running as a one-shot with an LED indicator and triggered by the photo-transistor when I fire a TV Remote at it. I am using the one-shot as a sort of debounce as I am not decoding the series of IR flashes I just need to detect a signal. The Red LED lights up for about 1s when the 555 is triggered. It works fine, except the maximum range is about 1 meter. What is odd though is that if I create a series phototransistor, resistor, LED circuit. The phototransistor will respond to a remote (red LED flashes brighter) from several metres away. The other odd thing is that the 555 circuit is sensitive enough to be triggered by indirect sunlight. So amplifying the sigal from the photo-transistor will simply increase false-triggers (I believe).
If would be grateful if anyone could point out what I am doing wrong.
Thanks
Mike.
I have labelled R1 on the schematic. Increasing the value of R1 increases the sensitivity of the trigger. I am using the two-legged version of a IR phtotrans that looks like an LED.
I am currently having a bit of a fight with an IR photo-transistor.
The schematic is simply a 555 running as a one-shot with an LED indicator and triggered by the photo-transistor when I fire a TV Remote at it. I am using the one-shot as a sort of debounce as I am not decoding the series of IR flashes I just need to detect a signal. The Red LED lights up for about 1s when the 555 is triggered. It works fine, except the maximum range is about 1 meter. What is odd though is that if I create a series phototransistor, resistor, LED circuit. The phototransistor will respond to a remote (red LED flashes brighter) from several metres away. The other odd thing is that the 555 circuit is sensitive enough to be triggered by indirect sunlight. So amplifying the sigal from the photo-transistor will simply increase false-triggers (I believe).
If would be grateful if anyone could point out what I am doing wrong.
Thanks
Mike.
I have labelled R1 on the schematic. Increasing the value of R1 increases the sensitivity of the trigger. I am using the two-legged version of a IR phtotrans that looks like an LED.
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