New Boy

[Johnuready]

Hi, New to the forum and have a question re a led project.

I'm looking to back light a house name sign and thinking about:

Solar charging circuit
Storage battery
Dawn to dusk sensor
Led array
If possible a colour change circuity for Led's

Anybody have any ideas?

Okay with Arduino / building circuits etc.

[KMoffett]

Unless you have a well stocked junk box and insist on building it yourself it will be cheaper to buy one.
Said that, I googled: solar house numbers circuit
Got something simple, but cannot say it will do exactly what you want: https://www.circuitlab.com/circuit/qvvw7y/solar-recharging-led-system/
Also, Google Images: solar house numbers circuit
https://www.google.com/search?q=solar++house+numbers+circuit&tbm=isch&tbo=u&source=univ&sa=X&ved=0CB4QsARqFQoTCNiPjpix48cCFZAYkgod6KwGug&biw=1600&bih=740
There are many more.

Ken

[Johnuready]

Ken

Thank you for your help. The Circuit Lab looks great idea.

Any idea on what R5 would be if I use more than 1 LED?

Would I need to change TIP125 Darlington pair if more LED's are used?

Great to know a forum like this, I'm just getting back to electronics and programming after retiring.

Time difference as I'm in the UK

John

[KMoffett]

Sorry about the delay John. I didn't know you responded.

I think the first thing to spec is how many and what size LED's you want to use. Then you can work backwards for the other component values. Have you looked at commercial designs to determine how you want to build yours? A lot of designs have the solar cells on the top of the house numbers, and this may not be the ideal location for yours.

That circuit doesn't have a provision for dusk/dawn switching.

Since you are also into programming, you may want to use a microcontroller for charging and on/for switching. I have a liking for PICAXE micros. A UK product. http://www.picaxe.com/. Programs in BASIC, comes in a variety of sizes, relatively cheap, and only needs a serial cable (or a USB-serial cable) plus two resistors to program. Free software. "AND" they have a very helpful, and civil forum. It was originally designed for school children.

Ken
Minnesota, USA