How can I build a solar light??

[brbpab94]

I would like to build a solar light that is brighter then the one's you buy.I plan on useing old garden light solar panels 5.volts each and I just bought 100 17,000 mah led's.I would like to know what transisters,capacitors,photocells,ect that I would need.Is there an easy formula that a newbee could use.

Please help
Brian

[kikkoman]

Re: How can I build a solar light??

ohm's law?

[brbpab94]

Re: How can I build a solar light??

Is there a simple guide?

[stj]

Re: How can I build a solar light??

panels go through a low-voltdrop diode and maybe a current-limit resistor into batteries or capacitors.
they then connect to the led's through a current-regulated switching psu.

and obviously it needs a switch - either physical or optical or a timer.


that's how you do it right anyway.
and just for acuracy, your led's arent likely to be 17,000ma - i suspect they are 17,000mcd.

ma is a way of describing current, mcd is a way of describing brightness.

[brbpab94]

Re: How can I build a solar light??

panels go through a low-voltdrop diode and maybe a current-limit resistor into batteries or capacitors.
they then connect to the led's through a current-regulated switching psu.

and obviously it needs a switch - either physical or optical or a timer.


that's how you do it right anyway.
and just for acuracy, your led's arent likely to be 17,000ma - i suspect they are 17,000mcd.

ma is a way of describing current, mcd is a way of describing brightness.

17,000mcd is what I meant.What size capasitors would take the place of a AA battery?

[stj]

Re: How can I build a solar light??

cap's are rated by voltage & uf.

the voltage is just the safe limit, so for 5v anything higher.
the uf - higher is gonna hold more power.

you need to do some numbers,
how much current & voltage do the led's use,
how many leds do you want to run,
how long do you want them to run.

you need to know all this to calculate the minimum size of the battery or cap.

[Krankshaft]

Re: How can I build a solar light??

Capacitors? A super cap?

I can't think of any other cap resembling a battery.

Also hours of sunlight contribute to the total runtime less sun in the winter means less runtime for example.

[PlainBill]

Re: How can I build a solar light??

Go with a battery. The run time is MUCH longer per $ or unit volume. If you want something that will give a few minutes of light when you flip a switch, a cap might do it. For anything else, use a battery.

The first step is figuring out what the voltage drop and current requirements are for the LEDs you just bought. Then you figure out how long you want them to be on. Next figure out how much current and voltage those old panels supply. Now do the math.

PlainBill