Tuesday, May 18, 2010

Crazy Circuits

A DC circuit, or a direct current Circuit, is one in which all the elments are directly connected and current flows through each. It is essentially a closed loop through which cuurent can flow.

A DC circuit has certain required elements, it must have:

-a supply of energy (such as a battery or other source of energy to provide an excesss of electrons)

-a closed path in which to conduct energy (so that there is a path for electrons to flow)



Examples of DC circuits:


Series Circuit-in a series circuit the resistors are arranged in a series and if the stream of electrons is broken all the elements go off. In a series circuit the current is the same at all points along the wire and the sum of the voltage drops is equal to the voltage drop across the entire circuit. As you can see the current is .45 A along all point and the voltage of one of the light bulbs is exactly half of the voltage of the battery, it both are added together they will equal the total voltage.





Parallel Circuit-In a parallel circuit each resistor provides a new path for electrons so the total current is equal to the sum of the currents through each resistor. Because the elenments are in parallel, the volotage drop is also equal to the total voltage of the source. As you can see the voltage of one of the lightbulbs is equal to the voltage of the battery and the sum of the current is equal to the total current.




Combo Circuit-a combo circuit is a circuit that includes both parallel and series elements and the current in a complex circuit can be found by calculating the sum of the resistence in the parallel elements and adding it to the resistance of the series elements. Then you can use that resistence and the voltage of the battery to determine the current. The rules for the current of series and parallel circuits both apply, in all the series elements the current is the same and the sum of the current of the parallel elements is equal to the total parallel resistence. The same rules as previous circuits also apply to the voltage, the voltage drop of each parallel element is equal to the sum of the voltage in the entire parallel part of the cicruit. for the series part, the voltage for each series elements is equal to the total voltage for the entire series part of the circuit. as seen in the picture below the sum of the amperage in the parallel is equal to the total amerage and also the amperage in the series.the voltage of the series if added to the voltage of the parallel elements will equal the total voltage.


1 comment:

  1. You did a phenomenal job with your diagrams! Adding the voltmeters and ammeters provide an extra justification of current and voltage.
    Your explanations are correct, you clearly explain how current works but it is not very clear how voltage works. You basically say how addition of voltage works but not WHY it is that way.
    Please be sure that you understand how these two variables of circuits work as it is an important part of the final exam.

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