hi All

I looking for some help on a project that I need to do I need help with a light pole light I have the LED" super bright ( 3.2 to 3.4VDC @ 20mA ) Each I need to run 8 of them for 6 hours a day or more does and one know of a circuit and solar panel and battery's need and help please


charlie

 

The simplest solution is to go buy a box of 8 solar landscape lights for under $20. If you don't like the color, you can solder in your own LEDs.

 

He wants the LEDs to light in the daytime "for 6 hours a day" but solar garden lights light at night.

 

A day includes the night.

But yes, I assumed he wanted them on in the dark. If not, he could just cover the little CdS cells and they'd be on all the time.

 

I need to use the led I listed and it need to work on at night 6 hours does anyone have a circuit

 

For a circuit , some other data is needed. LED power required: 8 x 3.3 X .02 = .528 W X 6 = 3.17 Wh. Ni-Cd, AAs, = about .7 Wh or 5 + another for losses or the equivalent in other batteries. Brute force method- all 6 batteries in series driving 4 strings of 2 LEDs & 62Ω resistor. A 13V +_, solar panel @ 1W +_. Other batteriy V can be used then posibly requiring boost converter. Add light control and isolation diode and you have it. Figures not simulated or tested.

 

I need to use the led I listed and it need to work on at night 6 hours does anyone have a circuit

I revert to my first answer: Buy a solar landscape light (or get it free at a garage sale?) and replace the LED with one of your choice. I've done this with fine results. You're not going to beat the energy management features with a DIY solution anywhere near that price.

 

A solar garden light charges its rechargeable battery cell all day long. Its small solar panel needs full sunshine all day long in summer for enough charge for the LED to glow for 6 hours at night. Following an overcast day the charge is reduced so the LED does not glow at night or glows dimly for only 1 hour.

For 8 LEDs you need 8 solar garden light circuits with 8 solar panels or you can design your own circuit and use one huge solar panel made for trickle-charging a car battery.

 

I've been putting together a system like this for a remote sign lighting job. I spec'd a 60 watt panel, 20 aH AGM battery, Sunforce 7 amp charge controller and used the PIC based controller I've been working on. The light shown is about 12 watts at 12V. Here's some pics http://www.flickr.com/photos/20841173@N08/sets/72157626255969623/

If you're interested let me know and I'll give you the info to buy the PCB from SparkFun BatchPCB, parts list, source code, everything.

Basically your circuit needs to:

-monitor battery voltage
-get analog input from a light sensor
-make decisions on when to run the light and turn off based on light and battery voltage
-be able to switch an amp or two of current at 12V.