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# Solar Panels

I've been thinking about getting a solar panel. But i have questions about the output of the panel. Say the panel produces 24 V and i want to connect it to something that only needs 6 V, how would i connect the two. What kind of resistor would i need to balance the current in the circuit with the object drawing the current? Because i want free energy, but not something that will destroy what i connect it to. Do i need a resistor, capacitor of somesort? if so how would i connect it into the circuitry? I am really new with concepts of circuitry so can anyone explain to me step-step processes... Thanks

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Basic forumas to work with

Look here Resistance devices in series divide voltage proportional to their value. Resistance is related to "load". So, if you had a 24 volt potential and wanted to measure 6 volts that would be 1/4th of the total. You could use any four resitors of equivalant value or one resistance device that was three times the value of the device you wanted to maintain at 6v. The trick is in measuring the resistance of the device you wish to power and knowing how much current is required to power it. Your 24v solar panel becomes part of the circuit and has an internal resistance and it's internal resistance will change with the load on it. Also, adding resistance to drop voltage will cause you to lose power. What you really need is a conversion device that will reduce the 24v to 6v without dividing it down and wasting the current produced by your solar panel as it's purpose is to conserve energy. So, I would suggest you are not going to Radio Shack and buying simple components to do this. I might suggest that distributor of the panels might be a good resource to assist you. Good luck.
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In reply to: Basic forumas to work with

Ok, what you need is a DC "stepdown" transformer. Since these do not exist, here's how a non solid state device would be made if you can find the schematics and components needed. You will need to convert the 24V DC from the solar panel to AC. For this you need to come up with a simple oscillator/multivibrator and an amplifier. The multivibrator becomes a signal fed to a power transistor which acts as a switching device that turns the DC on and off. Two transitors using "push-pull" is best. This is fed to a stepdown transformer's primary windings. This causes a magnetic field to expand and collapse at the freqency of the multivibrator and this induces current flow into the secondary windings of the transformer. In a perfectly efficient transformer, the ratio of the numbers of windings in the primary and secondary coils determine the AC voltage change. Thus, a transformer with 4 times the windings in the primary would produce 1/4th the voltage (and 4 times the current) in the secondary....again, if 100% efficient which is not going to happen. Anyway, once you have your AC output from the secondary windings, you would rectify it. A simple diode bridge rectifier (4 diodes) was typically used. This produces a pulsating DC that needs to be filtered and attenuated. Here's where you need such things as capacitors and regulation devices such as other transistors, resistors and perhaps a Zener diode. When done correctly, you can bring your 24v down and increase your current as well. Solid state devices are available today which do this and you won't make this type with discrete components.

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Yeah, it is just that simple

Other people might have said "switching power supply" but why mince words?

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FIRST: this is not a "Forum Feedback" issue

FIRST: this is not a "Forum Feedback" issue,
you really ought to post this in a more appropriate forum area.

But, as long as you are here...
You never mentioned what you wanted to use the panel for, all you said was "I've been thinking about getting a solar panel."

As long as you are just thinking about it, then why are you thinking about buying a 24V panel for a 6V application? Solar panels can be configured to have different voltage outputs. A solar panel is constructed of a series of individual cells, all having a relatively low voltage, like in the 1 to 2 volt range (depends upon the material used and the amount of light).

So, just find a panel that has an output voltage already in your desired range.

If you were to wire in dropping resistors then to arrive at 1/4 the output voltage (24V down to 6V) means you would be wasting 3/4 of the output.

There are voltage changing circuits that will convert one voltage DC to a high frequency AC then using transformers to step that up or down to some other voltage and then rectify it back to that other voltage DC, but all that still is going to cost something in the conversion process.

Just find the right panel to begin with.

If you already have a 24V panel, then see if you can get to the wiring between the cells. If so, then you might be able to just use 1/4 of the cells to have your desired 6V output. If you are hoping to charge a 6V battery then you may want to consider using a slightly higher number of cells (or a slightly higher output voltage, like about 8V) so that you can actually recharge the battery and not just maintain some output voltage.

There are many things to consider here, and I am not going into detail here, not that I don't want to, but, like I started, this is not the appropriate forum.

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