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enter image description here

When I turn my circuit on the LED turns on but even in the dark the LED is still on.

Can someone help me?

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    \$\begingroup\$ Please edit your question to explain what it's supposed to do and what it is doing. "Not working" does not tell us anything. Is the LED on or off? What voltage do you see at pin 2 when dark and when light, etc. (The need for this information should be rather obvious.) \$\endgroup\$ – Transistor Jan 2 at 10:16
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    \$\begingroup\$ What's the purpose of only connecting a capacitor on the threshold pin (6) ? It's floating from a DC perspective. \$\endgroup\$ – Unimportant Jan 2 at 10:25
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    \$\begingroup\$ See this duplicate: electronics.stackexchange.com/q/414780/152903 \$\endgroup\$ – Solar Mike Jan 2 at 20:57
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    \$\begingroup\$ Followup of / related: How to convert light activated switch into dark activated switch \$\endgroup\$ – try-catch-finally Jan 3 at 8:48
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Pin 6 is floating.. connect pin 6 with pin 2. (By doing so you are connecting inverting and non-inverting comparator together.

and change the 4.7K resistor with 1M ohm variable resistor .

Slowly change the resistance and adjust the sensitivity based on your ambient light.

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  • \$\begingroup\$ Can 100k potentiometer do? \$\endgroup\$ – Delion Jan 2 at 12:33
  • \$\begingroup\$ Yeh.. you can try, better if you have some higher value. \$\endgroup\$ – Electron Jan 2 at 12:38
  • \$\begingroup\$ 100k potentiometer is the only available compotent i have hehe. Thanks :)) \$\endgroup\$ – Delion Jan 2 at 12:40
  • \$\begingroup\$ Should i remove the capacitor? \$\endgroup\$ – Delion Jan 2 at 12:40
  • \$\begingroup\$ yes that 100uf, 16V one \$\endgroup\$ – Electron Jan 2 at 12:41
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I suspect you have misunderstood how the 555 functions. Because there is a latch (flipflop) in the 555, an input on pin 2 can only set the latch; it cannot reset it - an input on pin 6 does the reset.

What you need is an analog comparator - google "light-activated switch". A dark-activated switch just needs the inputs reversed.

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