Reverse Photocell?

CCinPA

I have a solar-panel that produces 12-volts / 1-watt.  I need an in-line reverse-photocell(?) that will be on/dawn, and off/dusk.  Help? 

Estragon

Something like this?
https://www.amazon.com/HIGHROCK-Photocell-Switch-Photoswitch-Sensor/dp/B019BR5Y3U/ref=mp_s_a_1_2?keywords=12+volt+photo+switch&qid=1569161768&s=gateway&sr=8-2

NANOcontrol

For what purpose? The panel is producing power at dawn.  It this being used as a pilot panel to schedule things on when power is sufficient?  A load resistor and a $13 voltage timer relay module could do that.

CCinPA

Estragon said:

Something like this?
https://www.amazon.com/HIGHROCK-Photocell-Switch-Photoswitch-Sensor/dp/B019BR5Y3U/ref=mp_s_a_1_2?keywords=12+volt+photo+switch&qid=1569161768&s=gateway&sr=8-2

Just what I was looking for... Thanks! 

CCinPA

Estragon said:

Something like this?
https://www.amazon.com/HIGHROCK-Photocell-Switch-Photoswitch-Sensor/dp/B019BR5Y3U/ref=mp_s_a_1_2?keywords=12+volt+photo+switch&qid=1569161768&s=gateway&sr=8-2

LEADS AND LOADS HELP? 

Which wire(s) connect to which wire(s)?

PS: Yes I  know this is most likely below the basics  

Estragon

As nano said, it would help to know what you're trying to do.

The photocell description isn't clear on whether it can be set (or wred) for normally open or normally closed operation.  The description suggests it can, but the diagram suggests otherwise.  

If it's normally open, and closes when it sees enough light (or can be set or wired that way), it would power the load (eg small pump) only when there's light.  If it's normally closed, and opens with light, it would turn off the load (eg night/security light) when it sees light.

I think you could test this with a multimeter by checking for continuity between the black and red wires with the cell in light.  If there's continuity, it's normally open and closes with light.  If you have no continuity, cover the cell.  If you get continuity with it covered, it's normally closed. 

CCinPA

Estragon said:

As nano said, it would help to know what you're trying to do.

The photocell description isn't clear on whether it can be set (or wred) for normally open or normally closed operation.  The description suggests it can, but the diagram suggests otherwise.  

If it's normally open, and closes when it sees enough light (or can be set or wired that way), it would power the load (eg small pump) only when there's light.  If it's normally closed, and opens with light, it would turn off the load (eg night/security light) when it sees light.

I think you could test this with a multimeter by checking for continuity between the black and red wires with the cell in light.  If there's continuity, it's normally open and closes with light.  If you have no continuity, cover the cell.  If you get continuity with it covered, it's normally closed. 

I used the device you recommended:  https://www.amazon.com/HIGHROCK-Photocell-Switch-Photoswitch-Sensor/dp/B019BR5Y3U/ref=mp_s_a_1_2?keywords=12+volt+photo+switch&qid=1569161768&s=gateway&sr=8-2

Estragon said:

As nano said, it would help to know what you're trying to do.

The photocell description isn't clear on whether it can be set (or wred) for normally open or normally closed operation.  The description suggests it can, but the diagram suggests otherwise.  

If it's normally open, and closes when it sees enough light (or can be set or wired that way), it would power the load (eg small pump) only when there's light.  If it's normally closed, and opens with light, it would turn off the load (eg night/security light) when it sees light.

I think you could test this with a multimeter by checking for continuity between the black and red wires with the cell in light.  If there's continuity, it's normally open and closes with light.  If you have no continuity, cover the cell.  If you get continuity with it covered, it's normally closed. 

Estragon said:

As nano said, it would help to know what you're trying to do.

The photocell description isn't clear on whether it can be set (or wred) for normally open or normally closed operation.  The description suggests it can, but the diagram suggests otherwise.  

If it's normally open, and closes when it sees enough light (or can be set or wired that way), it would power the load (eg small pump) only when there's light.  If it's normally closed, and opens with light, it would turn off the load (eg night/security light) when it sees light.

I think you could test this with a multimeter by checking for continuity between the black and red wires with the cell in light.  If there's continuity, it's normally open and closes with light.  If you have no continuity, cover the cell.  If you get continuity with it covered, it's normally closed. 

CCinPA

Estragon: I used the device you recommended:  https://www.amazon.com/HIGHROCK-Photocell-Switch-Photoswitch-Sensor/dp/B019BR5Y3U/ref=mp_s_a_1_2?keywords=12+volt+photo+switch&qid=1569161768&s=gateway&sr=8-2

Estragon

Again, it would help to know what you're trying to do.  Also, I didn't recommend any particular solution, I asked if "something like this" was what you were looking for.  It's hard to recommend a solution when you don't know what the problem is.

CCinPA

Estragon said:

Again, it would help to know what you're trying to do.  Also, I didn't recommend any particular solution, I asked if "something like this" was what you were looking for.  It's hard to recommend a solution when you don't know what the problem is.

There really isn't a problem.  I'm just trying to insert the reverse photocell into the layout.  There is a 12-volt supply that used to go directly to the butterfly; but occasionally the power would drain by morning.  So I decided to enhance the design by adding a reverse photocell so the battery doesn't drain during nighttime.  Does this help?   

billybob9

Most people would use a timer to do this but in my case on a overcast day I also used a Photocell to save the battery from draining. I didn't have to figure out the wiring as it was Plug and Play. Remember a Photocell is just a resister that gets hot and physically moves a contact.

CCinPA

billybob9 said:

Most people would use a timer to do this but in my case on a overcast day I also used a Photocell to save the battery from draining. I didn't have to figure out the wiring as it was Plug and Play. Remember a Photocell is just a resister that gets hot and physically moves a contact.

I don't object to a timer... Suggest one? 

billybob9

If it's 12VDC any Lawn Sprinkler timer would work. From the simple to the most complex. Mine came out of my Inverter so was 120VAC ( plug & play ).

CCinPA

Is connecting the wires too simple of a question? Or am I so wrong there is not an answer? 

Attachments 

Estragon

If I'm reading the diagram right, the white wire is common, typically negative.  Black would be switched by the photocell to power (or not, depending on photocell light) the red.  Personally, I'd test my assumptions with a multimeter before wiring it up.

Anyway, if my assumptions are correct:
- White wire from cell is connected to the battery negative and load negative.
- Black wire from cell is connected to battery positive.
- Red wire from cell is connected to load positive.

An inline fuse (or breaker), sized for smallest wire used in the circuit should be on the battery positive.

CCinPA

Estragon said:

If I'm reading the diagram right, the white wire is common, typically negative.  Black would be switched by the photocell to power (or not, depending on photocell light) the red.  Personally, I'd test my assumptions with a multimeter before wiring it up.

Anyway, if my assumptions are correct:
- White wire from cell is connected to the battery negative and load negative.
- Black wire from cell is connected to battery positive.
- Red wire from cell is connected to load positive.

An inline fuse (or breaker), sized for smallest wire used in the circuit should be on the battery positive.

I don't know if I'll be able to sleep tonight until I can try this tomorrow!  

The little thinks in life... 

NANOcontrol

It could be a lot simpler if you understood electronics. Just as a thought exercise, Most buck converters go down to about 1.2V.  You set the converter to what voltage you want.  Then a CDS photocell across the adjustment pot.  Light hitting that reduces the resistance of the pot and lowering the output voltage of the buck converter.  Your LED light acts like a zener and doesn't conduct below a certain voltage basically turning the lamp off.  A diode will have to be added in series with the lamp to raise the voltage to about .7V to get it to turn off.

CCinPA

NANOcontrol said:

It could be a lot simpler if you understood electronics. Just as a thought exercise, Most buck converters go down to about 1.2V.  You set the converter to what voltage you want.  Then a CDS photocell across the adjustment pot.  Light hitting that reduces the resistance of the pot and lowering the output voltage of the buck converter.  Your LED light acts like a zener and doesn't conduct below a certain voltage basically turning the lamp off.  A diode will have to be added in series with the lamp to raise the voltage to about .7V to get it to turn off.

I wish too that I knew more about electronics!  

Today... I tested without the buck-converter.   Although I had 12+-volts into the photocell... No output from the photocell with/without sunlight.  

Mouthpear

Did you ever find what you re looking for? If not I might be able to help.