There is one born every minute I drank the KoolAid - Page 1
Forum section: electronics / beginners

author: IVLRNR
author_rank: Contributor
timestamp: December 19, 2020, 11:25:05 am
content: So. After months of watching EVVBlog, and trawling the net and these boards, I went mad and bought:2 x Fluke 87v multimeters (UPDATE: Just discovered one is an 83v no wonder it was a bit cheaper. I feel cheated; but I think it is still good enough?I will buy a gossen sometime in the future to make up for getting a lesser meter than I thought)1 x Hakko F888D Soldering Station1 x various heat mat, solder, Ryobi drill, screwdrivers, pliers, side cutters, a corded dremmel, desk vise and lots of other stuff, at mostly full price lol.I have been trying to grapple with the KVL and KCL laws, I get Ohm's Law in simple DC circuits and have been working on my maths, and algebra as watching heaps of Electronics videos etc.I have also been accepted into Tafe doing Electronics and Comms, and Computer Systems Diplomas for next year. UPDATE: Not following through on the Tafe route, because of time available, travel, and thinking I will enjoy my time more working at my own pace.Haha. I really hope I 'get it', or I have definitely wasted a lot of beer money! A fool and his money are soon parted.Just thought I would let you guys know that I was inspired by what you write and will be doing my best get up to speed to better understand a lot more of it.I figure, this is a science and an art, and while I would like to be effective at it, it is probably going to be a life time thing.Regards,IVLRNR

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: December 19, 2020, 11:36:09 am
content: Good on you. It sounds like you're enjoying the journey so far and that's the main thing, I believe.

author: Ian.M
author_rank: Super Contributor
timestamp: December 19, 2020, 12:22:43 pm
content: Learning to use a SPICE simulator and associated schematic capture package effectively will reward you for the rest of your career. Once you've learnt one, migrating to others is far less challenging, as you already know what capabilities it *should* have.If you haven't already, I strongly recommend downloading and installing the freeLTspicecircuit simulator. Its not the *BEST* SPICE simulator available, but its arguably the best free one as Linear Technology (now wholly owned by and merged into Analog Devices) practices 'dogfooding', using it for all development work its capable of, so its had a lot more 'torture testing' than the alternatives. It runs well on Windows and under WINE on x86 or x64 LINUXes. The OSX Mac version is generally usable but has a few UI issues.LTspice is commonly used for sharing circuit ideas on this and other electronics forums, user groups etc. as its available free to any PC owner, and its file formats are mostly human readable text files, so raise less security concerns than competitors that use proprietary binary files.You can also use it to check the answers for the KVL and KCL problems you are working on, and use its schematic editor to aid rearranging circuits to simplify them. *TRY* to resist the temptation to click the 'run' icon before you've solved the problem analytically!Next you need some real hands-on stuff to work on. To provide good suggestions we need you to answer a few questions. e.g.What areas of electronics specifically interest you?Do you ever think: "I'd like to build a ......."?Do you want/need to repair a ......?Do you have other hobbies that could intersect with your interest in electronics?

author: fourfathom
author_rank: Super Contributor
timestamp: December 19, 2020, 03:06:38 pm
content: Quote from: IVLRNR on December 19, 2020, 11:25:05 amScience: YesArt: YesLifetime: YesBest of luck to you, and enjoy the journey. It can be incredibly rewarding.

author: rstofer
author_rank: Super Contributor
timestamp: December 19, 2020, 03:30:32 pm
content: Quote from: IVLRNR on December 19, 2020, 11:25:05 amKCL is really important when analyzing op amp circuits. It is used throughout Dave's Op Amp video but around 17:00 is a good example at the inverting input.https://youtu.be/7FYHt5XviKcNorton and Thevenin theorems will show up shortly.Nobody has an easy time with the math when first starting out. To the extent that electronics is a science, it will, like all sciences, be based on math.

author: Electro Fan
author_rank: Super Contributor
timestamp: December 19, 2020, 03:59:03 pm
content: Quote from: Ian.M on December 19, 2020, 12:22:43 pm+1Two quick start LTspice intros:https://youtu.be/abyxz8jfgK4https://youtu.be/A7oLq6VRDkY

author: rstofer
author_rank: Super Contributor
timestamp: December 19, 2020, 06:32:16 pm
content: Wander through this thread for examples of the various math tools in common use:https://www.eevblog.com/forum/beginners/old-dog-new-tricks/msg3367154/#msg3367154If you have to plot functions, tryhttps://www.desmos.com/If you want to solve equations, tryhttps://www.symbolab.com/Desmos and Symbolab are especially useful to the calculus student and, sooner or later, electronics becomes a calculus problem.Make friends with Octave, the open source equivalent of MATLAB.While you're at it, make friends with Python and the NumPy library. Jupyter Notebooks may be useful, I'm just learning about them. I like the Spyder IDE myself.

author: fourfathom
author_rank: Super Contributor
timestamp: December 19, 2020, 06:57:31 pm
content: All this simulation is very useful, but to really get the infection established you ought to build stuff as well. Kits, raw components and protoboard, solder and wires -- it's all good. Get yourself a cheap power supply, and eventually a scope. Even one of those $150 "tablet" scopes will be very useful:https://www.amazon.com/gp/product/B088WMV3DVHowever you do it, get your hands dirty and smell the solder smoke.

author: Ian.M
author_rank: Super Contributor
timestamp: December 19, 2020, 07:17:46 pm
content: +1 for building/fixing real stuff, but until we have some idea of the O.P's interests within the very wide field of electronics we cant make decent hardware/project recommendations.

author: rstofer
author_rank: Super Contributor
timestamp: December 19, 2020, 08:33:23 pm
content: Quote from: Electro Fan on December 19, 2020, 03:59:03 pmThe video at the first link shows a VERY different (old) user interface. The 2d is much better in that regard.Here's Dave's introductory video. There may be others, I didn't search...https://youtu.be/FEGT5dUpdrc

author: Electro Fan
author_rank: Super Contributor
timestamp: December 20, 2020, 08:46:25 pm
content: Quote from: rstofer on December 19, 2020, 08:33:23 pmYep, first one is old but it’s short enough that someone who just wanted to learn what it is might make it far enough into the ~8 min to decide it’s potentially feasible/worthwhile, and then watch the 2nd.No doubt LTspice and other such apps are cool and useful but I think they have to entice users to invest enough time in learning the app - otherwise some potential enthusiast users might remain glued to physical test equipment, calculators, and spreadsheets. It’s a bit of a Catch-22 because if such users could just start operating an app as powerful as LTspice they might be able to save a lot of $ on test equipment, but to really understand and appreciate LTspice most users would probably first need some experience with physical test equipment.At the end of the day physical test equipment is likely to be the hook that gets users enthusiastic enough to tackle LTspice. So for new users building a personal lab it’s probably a second or parallel step alongside populating a bench with at least some basic physical TE. After that it’s just a matter of making the app appear approachable in a way that leads to reasonably quick and reinforcing success. I suspect for trained EEs and/or adept software users it might be an easier bridge to cross than for enthusiast users who are highly hardware prone.So the trick is to ease the immersion.

author: IVLRNR
author_rank: Contributor
timestamp: December 22, 2020, 06:56:38 am
content: Thank you. Yes. I think it is all about the journey, with the destination being secondary. There is heaps to engage with, and lots of new experiences to be had.

author: Kerlin
author_rank: Regular Contributor
timestamp: December 22, 2020, 07:48:24 am
content: Good on you a proper course that's the way to go.from my experience too many techos have far to many gaps in their knowledge and just guess their way through.I have employed people with no experience or training to change two particular faulty electrolytics in cordless phones, when they left they put on their resume that they were a technician.Couple of items of advice -Its not whether theory or practice is more important you must have both to master the art.Give up or mostly give up your electronics hobby when doing the course.When I did my original apprenticeship I spent so long playing with my hobby electronics that I nearly failed the course!In fact I did fail but luckily they allowed a supplementary exam for any one subject only, that was a long time ago.What TAFE are you going to?

author: IVLRNR
author_rank: Contributor
timestamp: December 22, 2020, 08:22:08 am
content: Thornlie?

author: IVLRNR
author_rank: Contributor
timestamp: December 22, 2020, 08:36:31 am
content: Next you need some real hands-on stuff to work on. To provide good suggestions we need you to answer a few questions. e.g.What areas of electronics specifically interest you? I have an interest in generally all areas, home automation, Scada, PLC, but I am looking to build some basic skills in simple circuits and devices for now. Maybe even Alarms, Industrial Computing and systems?Do you ever think: "I'd like to build a ......."? Yes. All the time, I think could I build easily a device that tells me when I have mail, (Cheaply) without unlocking the door. I also think about building my own home sensor systems for emailing status updates to myself, and kind of SNMP traps with hardware components, like when a door opens, or the roller door goes up?Do you want/need to repair a ......? Yes. I would like to be able to repair home appliances like washing machine (although I am not sure if you have to be licenced), I also would like to be able to repair home phones, remotes, microwaves (again might be prescribed work), etc? I would like to know how to fix televisions, stereos, amplifiers, and such, although that might be too specialised? Just in general to be able to fix stuff that can be cheaply fixed without throwing it out, and having to buy another; which then eventually breaks and you have. to buy another etc.Do you have other hobbies that could intersect with your interest in electronics? Yes. I am a licenced telecommunications cabler, and have some I.T training and skills, but in both fields, I have stalled and could learn and be much more, but I am a bit obssessed with CISCO studies and need to develop those areas considerably more, but hope to merge some Electronics training and skills, along with a intense rework of telecommunications and I.T?I am not entirely sure at this time, what realistic expectations I can have with Electronics, because it is so specialised. I don't think it is viable at this stage or likely ever to consider being skilled enough to make money from it. But I can't draw, and I have no artistic or musical ability, so maybe this can be a rewarding path, just because it is a path. I need to be more informed about it, before I can chart a realistic progression or personal improvements; right now it seems incredibly ... vast! lol. Hope I have answered your questions?

author: Kerlin
author_rank: Regular Contributor
timestamp: December 22, 2020, 09:04:53 am
content: Don't know that one attended TAFEs and other colleges for 52 years in Melb and Syd so thought I may know it. Not important.I told someone that once and they told me I must be a slow learner LOL.

author: IVLRNR
author_rank: Contributor
timestamp: December 22, 2020, 01:12:58 pm
content: Haha. It is in Western Australia. We are on the other side of the Island.

author: Kerlin
author_rank: Regular Contributor
timestamp: December 22, 2020, 10:11:35 pm
content: Yep I knew that as I had googled it.And its a continent.

author: rstofer
author_rank: Super Contributor
timestamp: December 22, 2020, 10:29:41 pm
content: Once you get passed E=I*R and before you get bogged down in KVL and KCL, you might enjoy playing with transistors. It is good to get a general feel about the voltages around a transistor circuit. Yes, Vbe will be about 0.7V and VceSat will be around 0.2V - now prove it! Control and measure the base current and watch the collector current. The is hFE - the DC current gain.when I mentioned earlier about being able to look at a circuit and deduce what it was going to do. Well, there's a place to start.w2aew has 3 videos on transistor amplifiers 113, 114 and 185. They are terrific videos, highly recommended. Just Google for 'w2aew transistor amplifiers'.https://youtu.be/c6cmkm3UPUI-- #113 for a startYou won't be able to duplicate the tutorials without a scope but, in terms of the DC current gain, two DMMs is all it takes.Now we're talking real electronics...Stock up on 2N2222A, 2N3904, 2N3905 Toss in some 1N4148 or 1N914 diodes - general purpose switching diodes.

author: CharlotteSwiss
author_rank: Frequent Contributor
timestamp: December 23, 2020, 01:37:23 am
content: Quote from: IVLRNR on December 19, 2020, 11:25:05 amkeeping this forum consulted certainly helps a lot, you always learn something

author: CharlotteSwiss
author_rank: Frequent Contributor
timestamp: December 23, 2020, 01:43:02 am
content: Quote from: rstofer on December 22, 2020, 10:29:41 pmI'm going through it too; I had obvious shortcomings on the transistors, now I have started to study better at least the BJT: interdiction, saturation, active zone. And then use it as a switch or amplifier etc etc ... The base resistor, common emitter etc.It's not as easy as figuring out a resistor or a diode, but it's very interesting.

author: rstofer
author_rank: Super Contributor
timestamp: December 23, 2020, 11:40:43 pm
content: With quality videos like Dave's and w2aew's along with a little bench time, the subject can become quite simple.Once you see it and touch it, it's real and a lot easier to understand.Right after transistor amplifiers comes op amps. These are some marvelous gadgets.

author: rstofer
author_rank: Super Contributor
timestamp: December 25, 2020, 01:40:03 am
content: Then there are datasheets. Every single number or graph is there to limit what you can do with the device. Every number or graph is important!Here is the datasheet for the 2N2222A, a transistor that has been in production since 1962 (started as the 2N2222):http://web.mit.edu/6.101/www/reference/2N2222A.pdfNote how HFE(DC Current Gain) varies all over the map as a function of collector current. (Page 2 of 5)Then note how Hfe(Small Signal Gain) also varies widely. These are the things that drive designers nuts. You have to figure the worst case for your project and see how the devices can be made to meet the criteria.

author: CharlotteSwiss
author_rank: Frequent Contributor
timestamp: December 25, 2020, 10:19:58 am
content: I have been studying bjt transistors for 10 days, an interesting graph in the datasheet is the one at static work, where to draw a load line, to understand the working points in the active, saturation and interdiction zone; very interesting

author: IVLRNR
author_rank: Contributor
timestamp: January 13, 2021, 07:09:51 am
content: Yeah. I have just started on Diodes and Transisters. Not difficult, I just think you have to (or I do), have to keep going over it; till you see it clearly. I think for me there is lots of rote learning until the automatics of function and particularly terminology are locked in. Interesting stuff.

author: rstofer
author_rank: Super Contributor
timestamp: January 13, 2021, 04:54:46 pm
content: When you get into diodes and transistors, try messing around with Diode-Transistor-Logic. This was a common logic family in the early '70s. The whole chip thing started with Resistor-Transistor-Logic (RTL), moved to Diode-Transistor-Logic (DTL) and eventually settled at Transistor-Transistor-Logic (TTL) with a side excursion to Emitter-Coupled-Logic (ECL).Build up the NAND and NOR gates given in this page:https://electronicspani.com/diode-transistor-logic-gate/Entire computer systems (mainframes) were built on DTL. Thousands and thousands of 1N914 diodes. For the circuits presented, 1N914A or 1N4148 diodes would be appropriate and the 2N2222A transistor should work fine.The reason for the transistor is to restore the logic levels. As you add more and more logic in series, the diode voltage drops would tend to accumulate. Adding the transistor implied doing an inversion and the most common gates were (and still are) NAND and NOR.I'm going to toss out 'product of sums' and 'sum of products' as these relate directly to NOR and NAND logic but I'm going to leave the homework to interested readers. I'll also mention that Boolean Algebra is all about how to get to one form or the other. I'll also mention that my only interest in EE school was digital systems...