PV Gap

Duane Said:

Will a 4.5 volt charger burn up a 3.7 volt cell phone battery? If so, what resistor would I need to kill .8 V?

We Answered:

Dont use resistors, try using a Zenor Diode. The diode will kill .6 volts. As for resistors, you want a resistor to slow down current. It is current that will kill a drained battery while voltage kills a full batt. You will need to rectify the panel so that the full battery doesn't unload into the panel during off peak hours. The diode, a one way current valve, requires .6 volts to overcome the pn junction.

Brittany Said:

Charge Portable Devices with Solar Charger?

We Answered:

I have a travelling job, so it is very difficult for me to charge my laptop where I couldn't get power outlet. So I came to this website http://www.solargadgetsinfo.com/solar-chargers1.html they have great information on different types of solar charger.

I bought my solar universal charger from them and it is working really good. Now I do not have any limitation to work near power outlet. I can work anywhere and use my iPod anytime, anywhere.

You can find the solar charger at http://www.amazon.com/gp/product/B001L0POUO?ie=UTF8&tag=wwwsolargadge-20&linkCode=as2&camp=1789&creative=9325&creativeASIN=B001L0POUO

Ralph Said:

Small Scale Solar Cell Applications?

We Answered:

2 square inches of solar cells do not produce much power. So practical applications would either be devices that use very little power (solar powered calculators) or charge batteries for later use (Lamps used to light the edges of paths at night, they are pretty cheap & widely available in case you want to salvage the solar cells and batteries from one of them for your project).

You can buy solar charged flashlights and cell phone chargers, but I don't think they are all that practical unless you don't have grid power.

There are quite a few people who make little solar power gadgets. Try googling "beam robotics"

See links for lots of pictures!

Heather Said:

Is there a solar powered portable "charger" that might be used to recharge a cell phone ?

We Answered:

You will never charge your cell phone from a 12 dollar solar panel. Well maybe you can if you leave it hooked up for three of four days or longer.

This website has roll up or foldable panels that are made just for charging cell phones or IPods. There are even portable solar energy systems that are smaller then a laptop. The deal is you need to charge it in the amount of sun light you have. A hand crank would ware out your arm cranking it for hours to charge your phone or most any battery.
http://store.oynot.com/posopr.html

Viola Said:

Solar Charger?

We Answered:

Amazon.com and Target.com have solar chargers for iPods.
Not sure about the other apps.
Good luck!

Tony Said:

How would I convert 6.6 Volt DC to 5 volt DC?

We Answered:

You can make a simple series voltage regulator. Any electronics book would carry the circuit diagram.The components are:
npn transistor BC547 -1
Zener diode 5.6V,1W -1
:Resistor 0.25W, 100 ohm -1
I don't have the means to draw the circuit diagram here. The solar cell of 6.6V is connected between the collector of transistor and common point. Resistor is connected between the collector and the base. The diode zener is connected between the base and the common point. The battery to be charged is connected between the emitter and the common point.
Respect the polarity of transistor, diode zener, solar cell and the battery.