Questions about EE in general (NOT HOMEWORK)

[insignia96]

Okay, first off, i am 14, i am in higher math, but i am not in physics or any other higher classes so there might be some stuff I need explained in terms that may seem pretty basic. I understand most of the basics about EE, at least I hope I have it right :p, and I still have a few questions. Hopefully someone here can help me grasp some of these concepts better. To start I'll list what I already know, and throw in some questions as I go.

Volts is the unit for measuring potential of electrical current above ground, so 1v is exactly 1 volt higher than ground. Therefore, is ground a constant? All ground is the same? So to get higher voltages you will be giving it more potential?

Amps is the amount of power there, i think it is defined a current. 12V @ 1A ( this is all DC btw ) can power any circuit with a load of 12V that need 1 A or less? So how do joules fit into this, and coulombs? These concepts I need help with.

Now I understand a capacitor stores potential similar to a battery and and the amount that it can store is in farads. I think that 1 farad is the amount of energy required to change the potential by 1v?

Now for transistors, I thought I understood transistors until recently I realized i didn't really understand them very well, now transistors (to-92 style I am talking bout here) are like digitally controlled switches right? when voltage is applied at the base, the collector and emitter become connected, but what is current gain in a transistor and how does is work? and I thought transistors were solid state, so is the connection between the emitter and collector solid binary (on-or-off?) or does it vary with the voltage across the base.

As for diodes, I just realized a similar thing as I did with transistors, I thought they were just straight one-way electricity valves, the only reason for different models is max voltage and current ratings, but now i seem to be wrong? What don't I have in there for diodes?

the last question i have involves schematics, i detail it in the following image.
[PLAIN]http://img412.imageshack.us/img412/4236/schemau.png

Thanks to anyone who can at least help me with one or two of these questions, and once again i am only 14, I'm not stupid, but i haven't learned any math past a month or two of geometry and have only briefly paged through a physics textbook, so if these questions seem very basic to you there are still fairly complicated to me.

Thanks again,
Insignia96

 

[vk6kro]

Volts is the unit for measuring potential of electrical current above ground, so 1v is exactly 1 volt higher than ground. Therefore, is ground a constant? All ground is the same? So to get higher voltages you will be giving it more potential?

Try to forget about absolute potential. In EE, voltage is a relative thing. One wire may be 7 volts positive relative to another wire. Both wires may be in a satellite, but it is only the relative voltage that matters.

Amps is the amount of power there, i think it is defined a current. 12V @ 1A ( this is all DC btw ) can power any circuit with a load of 12V that need 1 A or less? So how do joules fit into this, and coulombs? These concepts I need help with.

Current and power are different things, although they are related. One definition of power is that it is the product of voltage and current, provided they both apply at the same time.
A joule is the work required to provide 1 watt for one second.
One coulomb is the amount of electric charge transported in one second by a steady current of one ampere

Now I understand a capacitor stores potential similar to a battery and and the amount that it can store is in farads. I think that 1 farad is the amount of energy required to change the potential by 1v?

No, a Farad is the unit of capacitance. The charge is measured in Coulombs and the voltage is measured in Volts.
Have a read here:
http://en.wikipedia.org/wiki/Capacitor

Now for transistors, I thought I understood transistors until recently I realized i didn't really understand them very well, now transistors (to-92 style I am talking bout here) are like digitally controlled switches right? when voltage is applied at the base, the collector and emitter become connected, but what is current gain in a transistor and how does is work? and I thought transistors were solid state, so is the connection between the emitter and collector solid binary (on-or-off?) or does it vary with the voltage across the base.

You can use transistors as switches or as amplifiers.
If you arrange the transistor so that it is half way on and then give it a small signal, it will work as an amplifier and give relatively undistorted, but bigger output.
If you have it arranged so that is off (ie no base current) and you feed a big signal into it so that it is forced into full conduction, then it works as a switch. The collector current goes from zero a lot of current with nothing in between.
You might use this to turn on a lamp or a small motor.
As for diodes, I just realized a similar thing as I did with transistors, I thought they were just straight one-way electricity valves, the only reason for different models is max voltage and current ratings, but now i seem to be wrong? What don't I have in there for diodes?

There are many types of diodes and different ways to use each type. They have to get a small voltage before they turn on, even in the forward direction.
Once they do turn on, they provide very little resistance to current flow and will easily self destruct unless the current is limited.
Different types have different capacitance, so they may or not work at high frequencies.

the last question i have involves schematics, i detail it in the following image.

The answers are "YES, YES, YES", but the part of the circuit shown as grounded should be connected to the negative terminal of the battery.

 

[insignia96]

Volts is the unit for measuring potential of electrical current above ground, so 1v is exactly 1 volt higher than ground. Therefore, is ground a constant? All ground is the same? So to get higher voltages you will be giving it more potential?

Try to forget about absolute potential. In EE, voltage is a relative thing. One wire may be 7 volts positive relative to another wire. Both wires may be in a satellite, but it is only the relative voltage that matters.

That's kinda what i thought, so that is why you can't connect one lead to the positive terminal of one battery and another lead to a different battery's negative terminal, because they each have their own ground and + where 1.5v is obtained in that specific reaction, but in another battery the ground in reference to that other battery's positive terminal might be very different? And those two wires then are the both at the same voltage? Or is one meant to be at 9v and the other at 16v?

Amps is the amount of power there, i think it is defined a current. 12V @ 1A ( this is all DC btw ) can power any circuit with a load of 12V that need 1 A or less? So how do joules fit into this, and coulombs? These concepts I need help with.

Current and power are different things, although they are related. One definition of power is that it is the product of voltage and current, provided they both apply at the same time.
A joule is the work required to provide 1 watt for one second.
One coulomb is the amount of electric charge transported in one second by a steady current of one ampere

That actually makes a lot more sense thanks :D !

Now I understand a capacitor stores potential similar to a battery and and the amount that it can store is in farads. I think that 1 farad is the amount of energy required to change the potential by 1v?

No, a Farad is the unit of capacitance. The charge is measured in Coulombs and the voltage is measured in Volts.
Have a read here:
http://en.wikipedia.org/wiki/Capacitor

Thanks 4 Link!

Now for transistors, I thought I understood transistors until recently I realized i didn't really understand them very well, now transistors (to-92 style I am talking bout here) are like digitally controlled switches right? when voltage is applied at the base, the collector and emitter become connected, but what is current gain in a transistor and how does is work? and I thought transistors were solid state, so is the connection between the emitter and collector solid binary (on-or-off?) or does it vary with the voltage across the base.

You can use transistors as switches or as amplifiers.
If you arrange the transistor so that it is half way on and then give it a small signal, it will work as an amplifier and give relatively undistorted, but bigger output.
If you have it arranged so that is off (ie no base current) and you feed a big signal into it so that it is forced into full conduction, then it works as a switch. The collector current goes from zero a lot of current with nothing in between.
You might use this to turn on a lamp or a small motor.

SO for a transistor i would honestly connect it with one speaker lead to my signal's ground, and the positive lead to a transistor's base lead, then use it to vary 9v on the collector to the emitter?


As for diodes, I just realized a similar thing as I did with transistors, I thought they were just straight one-way electricity valves, the only reason for different models is max voltage and current ratings, but now i seem to be wrong? What don't I have in there for diodes?

There are many types of diodes and different ways to use each type. They have to get a small voltage before they turn on, even in the forward direction.
Once they do turn on, they provide very little resistance to current flow and will easily self destruct unless the current is limited.
Different types have different capacitance, so they may or not work at high frequencies.

So I can't just connect a diode across the negative and positive terminals of a battery and not have it short out? (just an example, not planning on doing this)

the last question i have involves schematics, i detail it in the following image.

The answers are "YES, YES, YES", but the part of the circuit shown as grounded should be connected to the negative terminal of the battery.

Thanks!