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    IR photo transistor replacement, help needed

    hi, I wanna replace the photo transistor of the below circuit with the common ir receiver (shown in figure 2)
    so whats the new configuration ? :confused:
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  2. #2
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    Re: IR photo transistor replacement, help needed

    Hi,

    One of the photos hasn't loaded correctly.


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    Re: IR photo transistor replacement, help needed

    Quote Originally Posted by d123 View Post
    Hi,

    One of the photos hasn't loaded correctly.
    there it is
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    Re: IR photo transistor replacement, help needed

    If figure 2 is the one in post #1, you can't do it.

    The schematic shows a phototransistor that conducts when IR light falls on it so its collector voltage drops.
    The black device is a photodiode, it is normally used to produce a tiny voltage when light falls on it or in a mode where it passes a tiny current.

    You would need extra circuitry and a degree of experimentation to swap to the other device.

    Brian.
    PLEASE - no friends requests or private emails, I simply don't have time to reply to them all.
    It's better to share your questions and answers on Edaboard so we can all benefit from each others experiences.


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