Using old solar lights

[tblack007]

I'm wondering if anyone has had experience using old solar garden lights to light their layout?

I'm not too experience with electronics but this seemed like a good project. I have a number of old, inexpensive solar garden lights that I would like to hide in my layout to bring a little light to a few small structures. I have removed the bulbs and modified the enclosures to be moisture proof and fit nicely into the hiding spots. But I have a couple of wiring questions before moving on.

1. With the power/voltage/amps(?) from the solar, is there an issue with what type/size of wiring to use to extend the distance from the hiding spot to the structure.

2. Is there an distance maximum with this power to worry about.

Thanks to anyone with advice.

Tim

 

[grandpopswalt]

 I'm not sure what voltage is produced by these cells but I'd guess it's pretty low,   1 1/2 or 3 volts perhaps. And the current is probably in the low milliamps. so, I'd say that you can probably have your cells quite a distance from the lamps and wired with relatively small wire (#18 or #16) with virtually no voltage loss. #18 wire has a resistance of about .06 ohms per foot. So if your lights were 10 feet from the cells and they required 1/2 amp, then the voltage loss would be about .3 volts (current X resistance = voltage loss [.5X.6=.3]). Assuming that the cells/battery are rated at 3 volts, the lamps would be getting about 2.7 volts, that's more than enough voltage to shine brightly. With #16 wire your voltage loss would be 50% lower.

Hope that helps,

Walt

[Greg Elmassian]

 Most of them use LEDs, you can extend the wire pretty far, since the voltage and current is low.

They will not normally have enough oomph to run bulbs, both in voltage and current.

Regards, Greg

[ttrigg]

I use them all the time. Since the little cheap ones come as a single piece inside a plastic housing, I rip them apart. On the backside of the solar panel is the "electronics", the battery (NiCad), and the LED. There are two short wires connecting everything. I clip the wires in mid point. Drill a small hole in the roof to pass the wires through. Silicon glue the solar panel to the outside of the roof, passing the wires through the hole. Solder the wires back together, and glue the "electronics" plate (w/batt and LED) to the inside of the roof. All is done. Have a look at the roof of Chateau de Vic to see what it looks like. I generally use the $4 garden lights from Wal-Mart or Home Depot.

Don't forget to replace the NiCad's every year.

I have used a multi-bulb unit, one solar panel that powered three separate lamps. I put the solar panel on the fence, ripped the bulbs out of the plastic lamp fixtures. Put the LED bulbs into the buildings, ran the wires over to the fence and plugged it into the solar panel. All worked well except the dogs loved to grab the wires running down the fence, thus damaging the house, destroying the LED bulb electronics panel. I've gone entirely to the method used in Chateau de Vic, as it allows me to move the buildings (cleaning, painting, or relocating, etc) without having to mess with any wires.