You'll never learn much about circuit design in a course.
You'll learn some useful fundamentals.
But to be a circuit designer take those fundamentals, and a compendium of circuits, like AoE, and ANALYZE them. (Be dubious of the explanations in books). UNDERSTAND WHY they work. THEN you can be a designer.
I was tinkering with circuits (and FLAMING many) for years before I went off to MIT. Now I was lucky, landing at Motorola just at the bare beginnings of integrated circuits.
I still learn something new every day. When that stops hopefully my heart will stop at the same time ;-) ...Jim Thompson
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| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
For a good analog guy it does not look bleak at all. But as Jim pointed out you don't really learn much about real design in courses, you've got to do that on your own. The reason why I did my masters was so I'd have the degree in my hands. The only times I ever needed it was for visas from governments etc. Nobody else ever asked about it.
How did I learn design? Mostly through the ARRL Handbook, cuts, bruises and umpteen spools of solder :-)
--
Regards, Joerg
http://www.analogconsultants.com/
"gmail" domain blocked because of excessive spam.
Use another domain or send PM.
The future isn't bleak at all, IMO; electrical engineering jobs will continue to pay well above average for the foreseeable future, even if the jobs do become scarcer in the U.S.
What kind of electrical engineering would you like to do? There are some areas where, OK, you really do need to be well-above-average in your intellect to make a go of things (people like Ulrich Rohde or Charles Wenzel definitely don't play with kids' gloves), but I'm convinced that for anybody who manages to make it through college with decent grades and a good understanding of what they were taught, your ultimate limitations usually tend to be largely self-imposed based on how much time and effort you're willing and able to put into self-study rather than your innate abilities.
I would suggest that you take a few digital logic classes and a few programming courses -- there are TONS of jobs out there for anyone who can manage to write a little C code for a microcontroller or a little Verilog for an FPGA, and many of those jobs are fundamentally pretty easy; they can tide you over while you're figuring out what you really want to do and find yourself a job doing it.
Objectively you may well be at a disadvantage from the twenty-somethings graduating with their BSEEs today, but keep in mind that of those kids, a very large percentage view engineering as just a 9-5 job and will never expend much if any effort outside of work to improve their skills. Your years of having electronics as a hobby will give you a leg-up here.
I just put the empty of my first spool of solder I used in RST Engineering in a jewel window case on the wall. It was on my very first RST project in 1973 and I opened my second one-pound spool on the replacement for that first product about a year ago. Of course, I may have used bits and pieces of other spools from time to time, but the date I wrote on that first spool is still valid ... Thanksgiving Day, 1973.
As my brother the football star (and PhD economist) once noted, "Damned few like us, and none to replace us."
Warning: brute force method. The advantage here is that it always works, pretty much regardless of the circuit. The problem has five unknowns: currents through each resistor, and voltages on the node below R1 and R2. Let's denote them i1, i2, i3 and V1 and V2. From quick inspection we can write five Kirchhoff equations:
240*i1 + V1 = 8.4 (voltage drop on R1 plus V1 is the supply voltage) and of course the currents have to add up in each node, i.e.: i1=.005+i2 and i2=.005+i3. Finally, the remaining voltages must be: V1=V2+i2*570 V2=i3*100
So, five equations with five unknowns--can be done by hand, but it's easiest to use a linear algebra program like Octave (or Matlab if you have extra cash and don't have Octave). With little practice it's trivial to just write out the matrices, but for completeness here's how to do it systematically.
We gather coefficients for each unknown in the respective column ordered as [i1 i2 i3 V1 V2], and move the free terms to the RHS:
and solve simply as a set of linear equations, using the command A\B resulting in:
0.0134615 0.0084615 0.0034615 5.1692308 0.3461538
again, these are the three current i1, i2 and i3, and two voltages, V1 and V2. The result is of course the same as everyone else, V1=5.169V and V2=0.346V.
I saw it, Dave! :) And enjoyed very much the time you spend there.
Of course, you are a very special person. Not many would just jump in like that and I very much respect what you did and what you offered to others in preparing the video, as well. It was (and is) a generous gesture, well above par.
It's hard for most of us to get a feel for what works without first having some idea of what to expect. Theory is primary to interpreting and understanding experimental result.
What isn't known through theory defines the word 'random.'
Yes, that makes sense, thanks. But the trick is finding the most useful equations. I tend to start with less useful stuff like VR1+VR2+VR3 =3D 8.4 and then substitute currents for voltages like (IR1
240) +(IR2 * 570) +(IR3 * 100) =3D 8.4 which ends up with 3 unknowns and needs a couple sheets of paper to figure out.
But, I misstated the current flow direction which should have been the other way. I get confused with source and sink currents and think of current going from the negative point to the positive, while others think the other way. The circuit has 15mA in the 100 ohm resistor for a voltage of 1.5 at V3 and 10mA in the 570 resistor for a voltage of
5.7+1.5 =3D 7.2 volts at V2 and the last 5mA goes into the 240 resistor for a voltage drop of 1.2. All equals 8.4
So, using your idea with the current going the other way,
You never substituted your equation for V2 into the preceeding equation (V1-V2=R1*...) -- you just took your equation for V2 and shuffled both sides around until you got 0=0! (Effectively you had one equation but two unknowns still -- V2 and V3 -- so the "0=0" tells you that there are infinitely many values of V2 and V3 that satisfy the equation. You need the additional constraint of the other equation to obtain a unique solution.)
That would be the professor's thought process. To us back then things we didn't understand were not random at all. For example, you simply "knew" that the Q of a power matching network had to be at least 10 or you'd get into EMI troubles. Or that grid-bias tube stages were way more stable by nature. Or that certain modes of operation in a transistor could lead to a phssst ... *BANG* (later I learned about the concept of a SOA), and so on.
If it was all random we'd have had much more failing parts and homebrew devices, but we didn't.
--
Regards, Joerg
http://www.analogconsultants.com/
"gmail" domain blocked because of excessive spam.
Use another domain or send PM.
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
Some engineering is empirical, based on experience, experiment, and instinct. Just because there's no effective theory doesn't mean we can't design things that work.
The best way to get a feel for what works is to build things. Most good electronics designers did that when they were fairly young, before they understood much theory.
I've made plates sag, but never blew any glass. ...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
Bitrex, Do you have a degree presently? Did you get another degree back in the deeps of time? If so, then go for a masters in EE. Easier, and more fun!
I ran an 807 (a 1625, actually, an 807 with a 12 volt filament) to the point where the glass sucked in on itself to make a VERY skinny tube, but it never cracked.
That is because you were not a ham radio operator on a tight budget. We had glass turning mildly liquid, being sucked in and ending up snug on the plates. That was the time to turn off the rig. A few seconds more in transmit and there'd be a loud bang.
--
Regards, Joerg
http://www.analogconsultants.com/
"gmail" domain blocked because of excessive spam.
Use another domain or send PM.
I knew to back off on the bias when the plates turned cherry red ;-) ...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
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