Ooooh! Politics!
10, 9, 8, ...
Nah Philosophy.
My brainlock is not about technical stuff but why people do bad things to others and/or themselves.
On my Transistor issue:
Here it is cause it just happened again with an NPN. Does the transistor "START" to conduct with the .7v on its base or is it fully on with .7? I think my brain lock is the voltage range at which it amplifies and isn't just a switch?
Can't wrap my brain around that. How stupid can you be?
Unless you have actually failed to understand/retain relevant theories of distributive justice (like Rawls'), rather than just disagreed with them, this seems like a bad example.
There is a difference between fair sharing based on income and wealth while paying taxes during your life, and taking a, sometimes big, slice of the pie that is often intended to make the life of loved ones better.
How is it fair that frugal people are penalized to cater for the willy nilly behavior of people that can't balance their checkbook, the government included for that matter.
And just like fourfathom, though I can wrap my brain around it somewhat dislike philosophy.
As I get older, I feel I have a limited capacity to learn new things, and have to be selective. It's like my brain is filling up. I feel that if I try to learn too much new stuff, my brain is probably going to erase old stuff to make room.
On my Transistor issue:
Here it is cause it just happened again with an NPN. Does the transistor "START" to conduct with the .7v on its base or is it fully on with .7? I think my brain lock is the voltage range at which it amplifies and isn't just a switch?
QuoteCan't wrap my brain around that. How stupid can you be?
Think about the mathematical concept called average and now translate what that means to a populations IQ.
Edit: break checking someone is stupid but taking advantage of that fact that you have a webcam to prove that someone was break checking you is equally stupid in many ways.
On my Transistor issue:
Here it is cause it just happened again with an NPN. Does the transistor "START" to conduct with the .7v on its base or is it fully on with .7? I think my brain lock is the voltage range at which it amplifies and isn't just a switch?
On my Transistor issue:
Here it is cause it just happened again with an NPN. Does the transistor "START" to conduct with the .7v on its base or is it fully on with .7? I think my brain lock is the voltage range at which it amplifies and isn't just a switch?
BJTs are current devices, not voltage devices. There is no simple easy relationship between a BJT's "input" and "output" voltage, so if you start there you are bound to be perplexed.
There is a single simple relationship between "input" current and "output" current; IC=hFEIB
So, start by working out the input (base) current, that will give you the output (collector) current. That current flowing through the load will determine the output voltage.
On my Transistor issue:
Here it is cause it just happened again with an NPN. Does the transistor "START" to conduct with the .7v on its base or is it fully on with .7? I think my brain lock is the voltage range at which it amplifies and isn't just a switch?
BJTs are current devices, not voltage devices. There is no simple easy relationship between a BJT's "input" and "output" voltage, so if you start there you are bound to be perplexed.
There is a single simple relationship between "input" current and "output" current; IC=hFEIB
So, start by working out the input (base) current, that will give you the output (collector) current. That current flowing through the load will determine the output voltage.Let's not start that.
In applications where the BJT is being used as a linear amplifier, it's always right to consider it to be a voltage controlled device, with IC being dependant on VBE.
Current control only makes sense when dealing with a saturated switch, but even then, in order to ensure a fast turn-off time, it's necessary to take the base voltage below the normal 0.6V diode drop, preferably even negative.
On my Transistor issue:
Here it is cause it just happened again with an NPN. Does the transistor "START" to conduct with the .7v on its base or is it fully on with .7? I think my brain lock is the voltage range at which it amplifies and isn't just a switch?
BJTs are current devices, not voltage devices. There is no simple easy relationship between a BJT's "input" and "output" voltage, so if you start there you are bound to be perplexed.
There is a single simple relationship between "input" current and "output" current; IC=hFEIB
So, start by working out the input (base) current, that will give you the output (collector) current. That current flowing through the load will determine the output voltage.Let's not start that.
In applications where the BJT is being used as a linear amplifier, it's always right to consider it to be a voltage controlled device, with IC being dependant on VBE.
This is why it's tempting - and useful - to say that a BJT is current controlled, but saying it's voltage controlled isn't wrong per se.
This is why it's tempting - and useful - to say that a BJT is current controlled, but saying it's voltage controlled isn't wrong per se.
Precisely.
IMHO for simple introductory purposes, the current version is easier to understand and analyse. OTOH, the more complex linearisations and translinearisations are fascinating.
This is why it's tempting - and useful - to say that a BJT is current controlled, but saying it's voltage controlled isn't wrong per se.
Precisely.
IMHO for simple introductory purposes, the current version is easier to understand and analyse. OTOH, the more complex linearisations and translinearisations are fascinating.But those are only somewhat usefull when the transistors are next to eachother on the same die. Otherwise process and temperature variations will introduce errors quickly. IC designers have to use quite a few tricks to match transistors used to build a good opamp. And even then the opamps on the same die don't behave exactly the same. Just look at the metalisation pictures in datasheets for some of the older opamps to see how complex some structures are to achieve good as possible symmetry.
This is why it's tempting - and useful - to say that a BJT is current controlled, but saying it's voltage controlled isn't wrong per se.
Precisely.
IMHO for simple introductory purposes, the current version is easier to understand and analyse. OTOH, the more complex linearisations and translinearisations are fascinating.
You missed the point that where transistor voltage control is actually useful (like current mirrors and other translinear circuits like multipliers), the transistors need to be matched closely where it comes to temperature and process to a point where that is only possible with the transistors being on the same die. So not really applicable to common transistor circuits where you'll need some form of feedback to cancel process and temperature variations in order to make a circuit behave. And in those circuits, using Hfe or Beta (current gain ) is a much more sensible approach.
This is why it's tempting - and useful - to say that a BJT is current controlled, but saying it's voltage controlled isn't wrong per se.
Precisely.
IMHO for simple introductory purposes, the current version is easier to understand and analyse. OTOH, the more complex linearisations and translinearisations are fascinating.
Math, especially once the big formulas come out. I understand the concept, but I just don't know how to start when it comes to applying it. I tend to get hung up on what each variable represents, and what unit to use as often it's not really specified. Ex: if looking at a data sheet.