You can use a DC relay powered by the solar cell to switch the LED lights OFF when there is light. NO ELECTRONICS to deal with!
and YOU CAN PUT THE LED LIGHTS IN SERIES BECAUSE LED LIGHTS DO NOT "BLOW" as a failure mode unless you apply way too much voltage, resulting in way too much current.

Can you give the relay link 0.5vdc normally closed? Meaning lower than 0.5vdc relay closes and above relay opens

 

No, I do not provide such a link because I do not spend much time searching for stuff. Such a relay may possibly require a stage of amplification. OR it might be a reed relay available from one of the reed relay companies.
Besides that, professional services are accompanied by professional fees.

 

Can you give the relay link 0.5vdc normally closed? Meaning lower than 0.5vdc relay closes and above relay opens

There's no such relay out there I know of that would respond to those voltages.
I posted two circuits that will operate a relay as required have you seen them?

 

Over the years I have come across sensitive relays.
If the solar cell being used to sense the sunlight has multiple segment then a few of them could be put in series instead of parallel.

 

Can you give the relay link 0.5vdc normally closed? Meaning lower than 0.5vdc relay closes and above relay opens

Many (most?) relays have both normally open and normally closed contacts. 0.5V is a bit more difficult.

 

Adapter 9V,
ON at 500 mV,
OFF at 534 mV
2 LED in one light,
LED current 92 mA (for long life).

10pcs/lot LM393 DIP-8 THROUGH HOLE
Price: $0.54, free delivery.
100pcs/lot 2N2907
Price: $0.54, delivery $0.66.
ADDED:

No ics please

IC LM393 used worldwide in automatic night light and street lamps.
See https://www.wellpcb.com/blog/components/lm393/
Of course, instead IC you easily can use circuit, assembled from discrete components:

 

There's no such relay out there I know of that would respond to those voltages.
I posted two circuits that will operate a relay as required have you seen them?

No relays please. No ics please

 

No relays please. No ics please

That makes it complicated. Why can't you use a photocell or LDR as the sensor instead of the solar panel?

 

That makes it complicated. Why can't you use a photocell or LDR as the sensor instead of the solar panel?

See post #1 link. Landscape light come with solar panel on top.

hard to put photocell or ldr on top on the light and make a hole for it.

 

hard to put photocell or ldr on top on the light and make a hole for it.

The LDR can be mounted on the enclosure that houses the electronics or even remote.

 

The LDR can be mounted on the enclosure that houses the electronics or even remote.
View attachment 330430

Stop feeding the troll. His only agenda is to “prove” we cannot meet his specification. I have refused to play, I wish the rest of you would. Of course, many of us could design a comparator from discrete components, or, at least look it up on the net, but I refuse to do that for no reason.

Other things I refuse to do include making furniture from trees using no power tools and making bread from wheat I grow and mill myself.

 

You have several choices open to you. Which do you prefer?

 

I got tired of coming out at 3AM and seeing my solar lights by my pond had run dry, so I replaced them all with low voltage garden lights.

Of course, I didn't like the light color (stark white) so I replaced the LED lamps with some others, disk type off EBay. These have quadrupled in cost since I did this but still worth it.

To power these things I got a Low-Voltage 30-Watt Landscape Lighting Transformer with Dusk to Dawn Sensor This not only powers things but senses dark. Simple. It works.

 

Stop feeding the troll. His only agenda is to “prove” we cannot meet his specification. I have refused to play, I wish the rest of you would. Of course, many of us could design a comparator from discrete components, or, at least look it up on the net, but I refuse to do that for no reason.

Other things I refuse to do include making furniture from trees using no power tools and making bread from wheat I grow and mill myself.

I you have refused to play, then why are you playing? Just unwatch the thread and be done with it. There are lots of threads -- most threads -- that I don't watch and therefore I don't care how many people post in those threads or how often they post.

 

I you have refused to play, then why are you playing?

Sometimes you just have to try to fix teh innerwebs.

 

Stop feeding the troll. His only agenda is to “prove” we cannot meet his specification. I have refused to play, I wish the rest of you would. Of course, many of us could design a comparator from discrete components, or, at least look it up on the net, but I refuse to do that for no reason.

Other things I refuse to do include making furniture from trees using no power tools and making bread from wheat I grow and mill myself.

People used to make these items when their was no ICs and without relays.

I am sure their is an expert here who can help.

if you dont know it then disregard this thread

 

Hi

I have the following landscape light:

Better Homes & Gardens Ellis 20 Lumen Solar Powered LED Outdoor Landscape Path Light - Walmart.com

It comes solar powered. I want to modify it so that it is only powered from plug no solar. I am going to use the following adapter to power the lights. The adapter range goes from 3VDC to 12VDC:

Amazon.com: 30W Universal AC/DC Adapter Switching Power Supply with 8 Selectable Adapter Tips, for 3V to 12V Household Electronics and LED Strip - 2000mA Max : Electronics

I am going to change the led in the landscape light to following which is 3VDC 100ma:

Filament Led White Light Bulbs | Led 8 Pcs Filament | Led Filament 10 Leds - 68mm Dc3v - Aliexpress


I am going to use solar panel that the landscape light comes with as my indicator if its night time or day time to turn lights on or off. I measured and determined from solar panel that at 0.5VDC or below it is dark enough so that the lights should turn on. Above solar panel 0.5VDC lights should be off.


Now my next challenge is to build a circuit that meets below all requirements.

Requirement 1. I want a circuit that constant 3 vdc if I put my adapter at 12VDC or 6VDC then I also want the circuit to output constant 3VDC. I would do 12VDC or 6VDC so I don't have to worry about voltage drop in field. I don't want to do resistor divider for the constant voltage because if future the adapter would not only power landscape light but also other items that are not 3VDC. I just don't know voltages right now.


Requirement 2. Turning lights off 0.5VDC or below and turning lights on 0.5VDC and above. Does anyone know how of good circuit I can build from transistor, resistor, diodes etc which can switch the led landscape light on at 0.5VDC or below and light of at 0.5VDC above?

If you do then can you please post it.

Thanks

OK, yes, I am aware of such a circuit. It is more complex than the relay I suggested. The one that I saw was CURRENT operated and quite a low resistance. AND that was a whole lot of years back, before the internet was even a dream. And so the company that produced the relay may not even be around.

So you need to consider some other sensor than the solar array, located someplace else in the garden area.
Consider that there ar a lot of companies that produce switches that sense the loss of sunshine and switch on lighting, it should be possible to access the opposite contact on one of those sensors for your application.
And evidently the solar panel is not movable, nor are the connections accessible.

 

People used to make these items when their was no ICs and without relays.

 

View attachment 330778

Can you please explain how the circuit works?

 

Can you please explain how the circuit works?

Briefly.
When the solar cell is below .5 volts Q1 transistor is OFF which allows Q2 to conduct which then turns ON Q3.
When the solar cell is above appx .52 volts Q1 turns ON which then turns OFF Q2 and Q3.
The circuit is known as a schmitt trigger. It will rapidly switch ON or OFF when activated by those voltages listed.
R6 is added to limit the current to 100ma on the LED, adjusted for the small voltage loss across Q3 (appx 200mv).
Circuit verified on the breadboard with the components listed.