Hello,
In a small building I have lights (220v) controlled by a latching relay operated by several push buttons located at the entrances.
Usually people turn on the light in the morning but never turn it off during the day when there is enough natural light.
I would like a circuit to turn off the latching relay when there is sufficient light but still be able to turn on manually the light at any time, so triggering only when natural light is going high but not when it is already high.
I have looked at off the shelf twilight switch, they use a 555 and operates a relay above or below a light threshold.
I was thinking of a circuit powered by the lights circuit (so only on when the lights are lit up) and that would detect going down a threshold of a LDR (light dependent resistor) but I don't know how not to trigger it if the LDR is already low at power on (to be able to manually power on the light).
Thanks for your suggestions
In a small building I have lights (220v) controlled by a latching relay operated by several push buttons located at the entrances.
Usually people turn on the light in the morning but never turn it off during the day when there is enough natural light.
I would like a circuit to turn off the latching relay when there is sufficient light but still be able to turn on manually the light at any time, so triggering only when natural light is going high but not when it is already high.
I have looked at off the shelf twilight switch, they use a 555 and operates a relay above or below a light threshold.
I was thinking of a circuit powered by the lights circuit (so only on when the lights are lit up) and that would detect going down a threshold of a LDR (light dependent resistor) but I don't know how not to trigger it if the LDR is already low at power on (to be able to manually power on the light).
Thanks for your suggestions