PV Gap

Jon Said:

I want run my security system off solar. How big of a panel do I need IF it needs 730mA at 9VAC.?

We Answered:

If your system will actually run on standby for 24 hours off a 1.2 ampere hour battery, it needs about 44 milliamperes (ma). Estimate no more than an additional 6 ma to maintain the battery. This is a total of only 50 ma. At 6 volts (DC from the battery) this is a total of 0.3 watts. The AC side of the system is said to need 730 ma at 9 VAC,or 6.6 watts. I think you would find that this much current is needed only when the system is in alarm. It has a local sounder.

You could measure the standby current with a cheap volt ohm ammeter. Kill the AC, put the meter on the ma range and connect one meter lead to a battery terminal, and the other to the wire that was connected to that lead. If the meter reads backward, you didn't hurt the meter. Just reverse the leads. The required number of ampere hours will be the number you read times 336 ( the number of hours in two weeks), divided by 1000. For my guess of 50 ma this would be 50 x 336 divided by a thousand, or 16.8 ampere hours. You would want a somewhat larger battery to allow for ageing

Now to the solar. The panel on the link is not a battery charger. Take a look at their other info, and you will find they have other units they call battery chargers. In addition to charging the battery, they should be able to regulate themselves so as to maintain the charge,but not overcharge the battery. I didn't see any 6-volt chargers though. there are several pages on solar battery chargers on the Internet. The charger must be one designed for the type of battery you use.

Joyce Said:

How big is the whole Solar System?

We Answered:

The solar system NeEvEr ends that's what I think....

Veronica Said:

How big is our Solar System?

We Answered:

It is about 4 light-years across (The gravity of the sun dominates until about 2 light-years away). It is inside the Orion Spur or Orion Arm, like it was called earlier. It is 26,000 light-years away from the center of the galaxy.

Paula Said:

What is the largest moon in the solar system? How big is it? What planet does it orbit?

We Answered:

Ganymede. It orbits Jupiter.

Nelson Said:

The huge black space where our solar system is, how big is and what really is it? Don't tell me just infinite?

We Answered:

Our solar system is a very tiny part of our galaxy, and our galaxy is a very tiny part of our universe. The galaxy is about 50,000 light years or so wide; the universe is about 60 billion light years wide. Not infinite, just really really big.