problem in IR sensor circuit
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i made this circuit on breadboard and when powered it with 9V battery the red LED started glowing. then i placed a piece of white cardboard with a 2cm thick black line over the IR LED and detector but the red LED doesnt stops glowing neither on black surface nor on white surface.😒😕
this is the spacing of my IR LED and IR detector as on breadboard-
![[IMG]](proxy.php?image=http%3A%2F%2Fimg180.imageshack.us%2Fimg180%2F7258%2F011020092744.jpg&hash=091740fb24c0dd47e58522f3d9c02e44)
i could not understand what the problem is.😒😒😒 please help.😕😕😕
![[IMG]](proxy.php?image=http%3A%2F%2F4.bp.blogspot.com%2F_RA2btAL9GeE%2FSL1ReSw_DjI%2FAAAAAAAAAPA%2FhmpVOR-h0eA%2Fs400%2FPhotodiode.jpg&hash=b1a09b637f6713b2aae4adf4d673c320)
![[IMG]](proxy.php?image=http%3A%2F%2Fwww.techitoutuk.com%2Fknowledge%2Felectronics%2Fcomponents%2Fresist%2Fpreset.jpeg&hash=4b01ec28b11d23552c3e7ae2aafd89dd)