Posts tagged ‘electricity basics’

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2011 May 16 22:37

World's Simplest Generator


Constructed the world's simplest generator, as per the instructions on William Beaty's site.

Magnet wire was hard to come by, so I just ordered a solenoid, which is a device that produces a magnetic field when an electric current is passed through it. I pried open the solenoid to find hundreds upon hundreds of revolutions of thin magnet wire.

I inevitably wound the wire too tight upon the first attempt, which constricted the movement of the magnets.

I was much more meticulous in making the box a bit wider for the magnets to have some leeway the second time around. I also wound the magnet wire loosely around the box.




The cost breakdown follows:

SourceQuantity Price ($)
Bulb (25 mA)Radio Shack11.49
CardboardUPS packaging1-
MagnetsRadio Shack47.99
NailLocal hardware store10.20
SolanoidElectronic Goldmine12.29
Bulb (25 mA)Radio Shack11.49
Grand Total13.46

2011 May 9 17:52
by roma

Magnetism and Supplies for Generator Project


After finishing DC electricity last week, I decided to learn magnetism in preparation for the Ultra-Simple Generator Project. The magnetism videos on khanacademy.org, which I finished today, gave me a pretty good understanding of the most important concepts.

Today, the solenoid I ordered for the generator project arrived. I ordered a multimeter and a breadboard for future projects, as well. I expected the breadboard to be bigger than it was.

2011 May 4 13:10
by roma

DC Electricity Review


One of the most important things in making sure that information is retained is to review it after learning. I got electricity down last week quite well, but haven't done a thorough review. So I decided to do the DC electricity test in Gibilisco's Demystifying Electricity.

The answer to the following problem (pg. 99) was e.

Seems to me like we may actually be able to figure this out:

E1 = (.07 A)(100 Ohms)
= 7 V

E2 = (.1 A) (100 Ohms) = 10 V

Etot = 10 V + 7 V = 17 Volts

We know that the resistances of I3 and I4 are equal. The voltage will be split in two, and so the currents should be equal as well.

Thus,
V3 = V4 = 17 V/2 = 8.5 V

I3 = I4 = (8.5 V) / (100 Ohms) = 0.085 A

I've posted this question on openstudy.com for help.

2011 April 22 10:16
by roma

Why Does a Battery Run Down?


Why does a battery run down?

Imagine zinc at the anode and copper at the cathode. The zinc forms a Zn2+ electrolyte and the electrons travel through the circuit. They wind up at the copper cathode and are then transferred into the electrolyte that contains positive copper ions.

A K2SO4 salt bridge connects the Zn2+ and Cu2+ electrolytes. The K+ ions in the salt bridge migrate toward the copper electrolyte and accept the electrons that are coming into the electrolyte from the circuit through a porous membrane. These electrons are transferred to the SO42- side of the salt bridge. The SO42- ions have migrated to this side because they are attracted by the zinc cations in the electrolyte. The electrons then pass through the SO42- ions, into the electrolyte and eventually back into the wires.

What causes the battery to run down?

2011 April 20 14:19
by roma

Who Knew Understanding Electricity Boosts Confidence?


I've gone through all but one of the electricity lessons on furryelephant.com. With illustrations and interactive applets through which I can see the effects of manipulating the voltage and current, this site has given me an understanding of the topic that was taking weeks to achieve otherwise.

I posted answers in the comments section of posts which had unresolved electricity-related questions. I posted questions about the concepts that are still not perfectly clear on openstudy.com.

Additionally, I joined the allaboutcircuits.com forum. I'm assuming there are a lot of resources on this site that I'm not yet familiar with. One thing that caught my eye was the experiments section. The very simple computer sounds cool.