Sun light sensitive switch

[goodjboy]

I have an led lamp that is powered by a 3.6v dc battery pack I threw together.

I want the lamp to turn on and off automatically based upon how dark it is outside. When it is sunny, I want it off. When it is dark, I want the switch on.

I want to order this online but I don't know the name of what I am looking for. Does anyone know what this is called and happen to know where a good spot to buy one would be online? Thanks!

 

[CocaCola]

They are called "Dusk to Dawn Photosensors"

But since you are talking battery operated and only 3.6 volts you might have to dig deeper as most commercial ones are made to run on mains power, or 12 volts...

There are low voltage ones out there as I have seen them on solar LED garden lights and the sorts but I don't know where you would find one over the counter...

But, you can almost certainly find a hobbiest circuit out there if you want to build one, as it's a pretty easy circuit...

 

[goodjboy]

Is there a way to use a small solar panel that is hooked up to a electronic device that is a switch? The switch will turn on with the voltage drops below a certain level? I am a newbie as you can see. I am trying to conserve the batteries in the led lamp. That's why I want the photo sensor.

 

[BobK]

A solar panel would be overkill. A light dependent resistor would be smaller and cheaper.

Edit: Here is an exmple of a simple circuit:

http://pcbheaven.com/circuitpages/Light_Dark_Activated_Relay/

Bob

 

[(*steve*)]

Is there a way to use a small solar panel that is hooked up to a electronic device that is a switch? The switch will turn on with the voltage drops below a certain level? I am a newbie as you can see. I am trying to conserve the batteries in the led lamp. That's why I want the photo sensor.

That's actually the way many solar lights work. Since they have a solar panel already, they can save the expense of an LDR by having it serve two purposes.

However, if you're not planning to have this thing recharged by solar power then the LDR is a cheaper and simpler alternative.