Electronics Technology -Part II-
 
        In the first part of the essay, I brought up the atomic structure, how it relates to the field of electronics, how to use Ohms Law ( E / R = I) to solve simple circuits, the metric units, and the amperes it takes to affect your body. Now we are going to get more advanced exploring the different forms of Ohms law, and introduce you to Powers law, Parallel circuits, Series Parallel, and Parallel series circuits.
 
    Ohms law, shown in the first part E / R = I is only one of the few...here is a small wheel that makes Ohms law a lot easier to remember. Later on in the course we will get into the algebra required to manually change E / R = I to the others but for now lets keep it simple.
 
    This is what, we call the Magic Ohm's Law wheel, and how you read it, makes remembering the actually calculations, easier. First off you have E on top, which means it will be divided by Either I, or R, (Example: E/R=I, or E/I=R) second off you have the I, and R on the bottom which signifies you Multiply these to get your results (Example: I x R=E) now that I've briefly explained how you use the wheel, lets go over a couple things, then try some calculations.

        Lets now explore what each letter signifies in electronic terms. First of we have the E, which in the field of electronics represents volts, Some wheels use V, instead of E, however I'm use to E. Second you have I, which represents Ampere's, and finally R which represents Ohms of Resistance.
Now that you've been briefed in this section lets try some calculations...
 

       If you figured 10 Volts, you are correct...        If you figured 0.5 Ampere's You are correct, however the correct notation of this would be 500 mA, this can be accomplished by using your engineering key, or for you math guru's moving the period 3 Positions right, and making it 5 to the negative 3rd, notated mA m= Milli and is -3.
          If you got 50 Ohms, you are correct.

        This concludes the section on Ohm's law, next we shall discuss more theory, by adding Powers law, to your knowledge.

    Powers law, is like Ohms law, but without the circle, and divided into sections. Below is a Table giving all the formula's in Powers law, in the sections

 
 
Power (Watts)
I x E = P
I2x R = P
E2/ R= P
I (Ampere's)
E / R  = I
P / E = I
P / R = Rooted = I
Resistance (Ohms)
E / I = R
E2 / P = R
P / I2 = R
E (Volts)
P x R = Rooted = E
P / I = E
I x R = E
 
       As you might notice the formulas from ohm's law are also in powers law, just there's many more formulas...most of them are self explained however there are two formulas I'd like to explain before going on, P / R = Rooted = I, what this one is saying is that Power Divided by Resistance, then Square root that answer = I
 
    And the other P x R= Rooted = E, this one is stating Power times Resistance, Square rooted, equals E...You might want to keep powers law, handy as we continue our exploration through electronics.

 

    And Now, on to Parallel Circuits....In the previous Essay I explained the basics of a Series circuit, now we are going to the next Step, Parallel circuits....

    Meet the Parallel circuit (excuse my terrible drawing) and prepare yourself for a shock, everything you know about series circuits is The Exact Reciprocal (Opposite) of Parallel circuits...Instead of adding the resistance's together which in this case would give you 20 ohms in series circuits, in parallel circuits this would be 882.352 mOhms, I can see your wondering how I came up with that answer, and here's what you do, first you take the reciprocal of each resistance add it to the next and at the end reciprocate back to normal, here's the formula incorporating the above circuit
    1/5= 0.2 + 1/10 = 0.3 + 1/3 = 0.633 + 1/2 = 1.133, now you take this answer 1/1.133= .882253 moving your period over 3 positions gives you 882.253 mOhms, your calculations will not be exactly to the number of mine, but should be close. Now also in series you had voltage drops different across each resistor, however in this circuit each resistor is getting 5 Volts, and dropping all 5, however the current through each resistor will be different.

    You take V / R to get the current through each resistor, so this would be your final calculations, or somewhere within 3% of them.

    Current through R1 = 1A
    Current through R2 = 500 mA
    Current through R3 = 1.666 A
    Current through R4 = 2.5 A
    Total Current is 5.666 A
 
    Just like Series circuits split voltage, parallel circuits split current, and don't change voltage, and like adding all the voltage drops of each resistor in a series circuit gives you the total voltage, adding all the current drops in a parallel circuit will give you the total current for this circuit, now lets say you want to find power (By using the formulas from powers law) I x E = P, so take your total current of 5.666 A times that by 5 Volts to get the total power for this circuit, 28.33 Watts is your total current. That my friends is the basics for Parallel circuits, now we will just touch on Series Parallel and Parallel series circuits.
 

    We will use the circuit above and modify it for both cases, first Series Parallel circuits

    Notice, the only difference in this one is R5, is right in the line with the Battery (Source) This totally, changes the effects on the circuit, and makes it more involved to solve. But here we go a step by step process to solve this circuit, first you add up your parallel branches the same way you did above to get a total of  882.253 mOhms, however now you just add like you would in a series circuit the 2 Ohm R5 to get 2.882 Ohms of Resistance, and now get IT, Or better known as Total current, you now have 1.734 Amps, see how much this one resistor off-set the calculations you got above. Now R5 has that total current going through it so you must know what the voltage drop across it is, to know how much voltage you have going across your 4 Parallel resistance's. You get 3.468 Volts drop across R5 so you take your total Voltage 5 Volts, and subtract 3.468 to get 1.534 volts, this is how much you have across each parallel resistor
    R1= 1.534/5 = 306.8 mA
    R2= 1.534/10 = 153.3 mA
    R3= 1.534/3 = 511.333 mA
    R4= 1.534/2 = 767 mA
Adding this together, you should get your total of 1.734 Ampere's, See how much more involved that makes it, the only difference between the above circuit, and the parallel series circuit is within the branches you have 1 or more resistors which you add up, it gets easier as you go, and if you want just add a Resistor in the same line as R1, make it a 2 Ohm and then when adding you first add those two resistors R1 and the one you added, together before adding all the resistance's together, and you would use the Branch Resistance total instead of each individual resistor in that branch.
 
                Next Essay will Cover, what type of Resistors there are, the Resistor color code, how they are made, and what they do in circuits.
 

                            (c) 1998 by Xomgromit
                                    E-mail: Smurd@hempseed.com