Electronic beginner - Page 1
Forum section: electronics / beginners

author: DkJing
author_rank: Newbie
timestamp: August 13, 2024, 10:02:55 am
content: Do you have any recommended e-learning videos for beginners?

author: tooki
author_rank: Super Contributor
timestamp: August 13, 2024, 11:35:56 am
content: Umm, you do know what EEVblog is, right?(Electronics engineering video blog.)

author: BILLPOD
author_rank: Frequent Contributor
timestamp: August 13, 2024, 01:06:10 pm
content: Good Morning DkJing, Enter 'electronics videos' into a Google window.

author: trilerian
author_rank: Regular Contributor
timestamp: August 13, 2024, 02:25:45 pm
content: Quote from: DkJing on August 13, 2024, 10:02:55 amThere is a sticky at the top of this page.https://www.eevblog.com/forum/beginners/electronics-primers-course-material-and-books/I recommend to start easy, use the free videos on Khan Academy. Once you learn the very basics with those you should have an idea what you need more practice with.

author: RoGeorge
author_rank: Super Contributor
timestamp: August 13, 2024, 02:36:38 pm
content: Quote from: BILLPOD on August 13, 2024, 01:06:10 pmAt some point in time, Google was banned or something in China, don't know if now Google is accessible from there.For the OP, if you can accessKhan Academy, they do have some very good e-classes (free) with video lectures, exercises, etc. These classes are taught by professors, educators and/or engineers.For beginners, I would recommend to start with the physics lessons about electrostatics, then electricity, circuits, and so on. The classes are nicely grouped by discipline of study and by year of study, so you can start from whatever level you want.

author: BILLPOD
author_rank: Frequent Contributor
timestamp: August 15, 2024, 01:17:51 pm
content: Quote from: RoGeorge on August 13, 2024, 02:36:38 pm

author: rstofer
author_rank: Super Contributor
timestamp: August 16, 2024, 04:59:23 pm
content: Videos, books and tutorials are all helpful but real understanding comes from experiments. Don't overlook having a couple of solderless breadboards, a rather complete set of resistors and capacitors along with some PNP and NPN transistors (2N3904, 2N3906). Try to come up with experiments similar to the lectures.Spend time with w2aew's videos, they are excellent.https://www.youtube.com/user/w2aew/videosYou will eventually need at least 3 DMMs to measure transistor base current, collector current and VCE Sat simultaneously. In the meantime, there are hundreds of threads around here about buying a DMM. On the low cost end, I like the Aneng AN8008https://www.amazon.com/Multimeter-True-RMS-Digital-Voltage-Resistance/dp/B083P26RPWThere are MANY meters to choose from in all price ranges. Maybe choose from those that Dave has reviewed (or, at a higher price point, the ones he sells). His meters are excellent.

author: SuzyC
author_rank: Frequent Contributor
timestamp: August 17, 2024, 05:47:01 pm
content: Rstofer, Nonsense. You don't need more than one DVM to measure three different simultaneous circuit currents or voltages, simply use one meter to measure each, one measurement at a time.Your advice to all doctors would be to use two stethoscopes at the same time to examine the two lungs of a person!To begin learning any cheapest meter/DVM would be just fine to start out with.

author: IanB
author_rank: Super Contributor
timestamp: August 17, 2024, 05:57:23 pm
content: A tiny hint on measurement technique:Measuring current directly is fiddly, since you have to break the circuit, insert the meter into the circuit, and then be aware of burden voltage of the meter.Instead, most circuits contain resistors (for biasing, feedback regulation, and other purposes). Therefore, to measure current, measure instead the voltage across suitable resistors that are already in the circuit, and infer the current using Ohm's law.Furthermore, most resistors are intended to introduce some kind of designed voltage drop, so measuring the voltage across a resistor may already be a useful circuit measurement.

author: tooki
author_rank: Super Contributor
timestamp: August 18, 2024, 03:12:52 pm
content: Quote from: SuzyC on August 17, 2024, 05:47:01 pmNo, he's absolutely right and you could not be more wrong.First of all, "simultaneous" meansat the same time, it does NOT mean "sequential". For simultaneous measurement, you need as many meters as you have measurements. By definition, you cannot take simultaneous measurements one at a time.Measuring multiple voltages and currentsat the same timeis a common thing, and often absolutely necessary. Not every set of measurements are so static that you can take the time to move around your meter. And measuring current with a regular multimeter means putting it in series, so to reuse the meter for a voltage measurement, you have to remove the multimeter from the current circuit, which changes it (since the DMM inserts some series resistance).And this isn't advanced stuff we are talking about: classic beginner experiments involve things like varying the voltage through a resistor or diode and seeing how the current changes in response. For this to not be horrifically tedious, you want to be able to see the effects in real time. rstofer's BJT example is another classic experiment.A frequent setup for many applications is four meters: input voltage, input current, output voltage, output current.And besides, he didn't say "you need 3 DMMs right away", he said that you willeventuallyneed them.Quote from: SuzyC on August 17, 2024, 05:47:01 pmA more apt analogy, but of your silly advice, would be that an ER doctor only needs to have one bed, because they can just use it one patient after another, since the doctor can only see one patient at a time.See how silly that sounds?

author: rstofer
author_rank: Super Contributor
timestamp: August 18, 2024, 04:18:53 pm
content: I was thinking about w2aew's transistor video at around 14 minutes where he is using 2 DMMs and 2 wonderful Simpson 260s:Transistor videos don't get better than this!

author: SuzyC
author_rank: Frequent Contributor
timestamp: August 18, 2024, 05:21:01 pm
content: Measuring current doesn't mean you always have to fiddle with jumper wires and interrupt a circuit to do this.Tooki..Haven't you ever heard of using shunt resistors and Ohm's Law to measure current?Using a circuit diagram and making notes, and just cleverly using a single DVM, an experimenter can reveal all the measurements needed to get to understand circuit operation.Rather than graduating to 3 DVM or so, having even the most rudimentary, used and even obsolete two channel scope would the best next tool to add to discovering circuit operation.But to start out to learn electronics, only a single DVM could enable understanding how a circuit works Making making multiple measurements, using shunts and especially doing some thinking, could be the most practical and useful tools needed.

author: SuzyC
author_rank: Frequent Contributor
timestamp: August 18, 2024, 05:44:06 pm
content: Like many other OP's of this type, as an analogy, you might clearly see that the patient has disappeared and what's left is a dozen doctors and brains surgeons discussing how to help.

author: Bud
author_rank: Super Contributor
timestamp: August 18, 2024, 06:44:51 pm
content: Multimeters are cheap these days and you can have 3 but I had 1 when was a boy and learned just fine. In fact, i still use one now decades later, though i have 3.

author: armandine2
author_rank: Frequent Contributor
timestamp: August 18, 2024, 07:27:07 pm
content: Quote from: DkJing on August 13, 2024, 10:02:55 amYou might find watching something like this point-of-view, day-to-day, world-of-work stuff helpful.I'm looking at a bass amp myself - one with a very good schematic but no video

author: tooki
author_rank: Super Contributor
timestamp: August 18, 2024, 08:40:05 pm
content: Quote from: SuzyC on August 18, 2024, 05:21:01 pmOf course I am familiar with that. It has some advantages, and some disadvantages.But it does NOTHING to address the core limitation with using one multimeter: SIMULTANEOUS measurement.Simultaneous does not mean sequential. It means at the same time. It is categorically impossible to do simultaneous measurement with an ordinary single-channel multimeter."Simultaneous" was a qualifier rstofer used. So non-simultaneous measurements do not satisfy the stated conditions.And I don't disagree that an oscilloscope is an essential piece of equipment that provides enormous insight into how circuits work. (But I don't see you recommending asingle-channeloscilloscope!)

author: J-R
author_rank: Super Contributor
timestamp: August 19, 2024, 06:31:35 am
content: I agree, a beginner doesn't need three DMMs. One is fine, along with a two or four channel oscilloscope, power supply, etc.The power supply will have voltage and current displayed. The scope channels can do a decent job as a DVM and can typically do math. So there you have a lot of simultaneous measurements without even bringing a DMM over.

author: Aldo22
author_rank: Super Contributor
timestamp: August 19, 2024, 08:28:04 am
content: Quote from: J-R on August 19, 2024, 06:31:35 amI don't think it's such a good tip."Beginner PSUs" have an inaccurate display and "misusing" an oscilloscope as a DMM can also backfire (remember: " EEVblog #279 - How NOT To Blow Up Your Oscilloscope! "). They are also not particularly accurate in DC measurement and prone to errors in (not) setting the appropriate V/Div.Any $10 DMM is better suited for this in my opinion.

author: watchmaker
author_rank: Unknown
timestamp: August 19, 2024, 01:13:06 pm
content: Quote from: DkJing on August 13, 2024, 10:02:55 amResponding to OP:I found Dave's EEVblog videos on theory and the Real Analog videos extremely useful as starting points.Setting up a learning program for self is difficult and depends on your goals. By definition, you do not know what you do not know.I want to understand theory as well as making. To this end I purchased some real textbooks (as opposed to downloading the PDFs). I have found Boylestad, LEARNING the Art of Electronics and Malvino's Principles of Electronics instructive. Also the lab manuals for these. I downloaded the Real Analog lab manual as well; but I prefer actual books so I can easily flip back and forth. I wish the instructor's manuals were easier to find.I do have a subscription to Kahn Academy and a couple instructional websites. Turns out each source has explanations and examples that compliment and clarify what others provide and this helps me to better understand the content.The great thing is that there are people on this forum who willcorrectmisunderstandings (THANKS!). They will teach in the process of correcting, but I think it is poor etiquette to ask for feedback without having put in the work.

author: J-R
author_rank: Super Contributor
timestamp: August 20, 2024, 02:20:06 am
content: Even cheap power supplies typically have 10mV and 10mA resolution. Probing with a scope is a critical step to learn and actually is much better than a DMM when you're trying to figure out why your circuit isn't working correctly. And in the case of a four channel scope, you can now have four values displayed at once on a single screen.I don't see a typical beginner going above 5V and many courses I've seen leverage batteries for the breadboard aspects anyway just to help with the blowing things up scenarios...Also depends on what kind of beginner, since a lot of folks just jump in to things like FPGAs and don't even get into analog circuit design. They're more coders than EEs.

author: IanB
author_rank: Super Contributor
timestamp: August 20, 2024, 02:26:39 am
content: Quote from: J-R on August 20, 2024, 02:20:06 amI'm not so sure about only 5 V. I think analog circuits with op amps and such like may benefit from 9 V or +/− 9 V supplies. However, two 9 V batteries in series can do this.

author: RoGeorge
author_rank: Super Contributor
timestamp: August 20, 2024, 06:20:39 am
content: Nevermind, the OP never logged into the account after posting the question, and probably didn't read any of the answers.

author: J-R
author_rank: Super Contributor
timestamp: August 20, 2024, 07:32:51 am
content: Quote from: IanB on August 20, 2024, 02:26:39 amOh, I'm not saying it's always the case. I just recall seeing a few courses using a small battery box with 4 AAs in series for their various projects. Seemed somewhat common.Quote from: RoGeorge on August 20, 2024, 06:20:39 amThe OP might come back, it hasn't been quite a week yet.

author: armandine2
author_rank: Frequent Contributor
timestamp: August 21, 2024, 11:04:05 am
content: Quote from: armandine2 on August 18, 2024, 07:27:07 pmthe amp appears to be fine - the 12" 8 Ohm speaker measures low resistance. And should be replaced.A theoretical exploration might include attached student zone material

author: Rick Law
author_rank: Super Contributor
timestamp: August 21, 2024, 06:02:57 pm
content: Quote from: tooki on August 18, 2024, 08:40:05 pmI think what should also be said is:any measurement disrupts that circuit, adding a shunt or not. Besides the shunt being an added element to the circuit -- which I assume is one of the disadvantageTookireferred to. Worst yet, the amount of disruption by this added element changes depending on the amount of Current. Yet more disadvantage I assumedTookireferred.Even if one uses an existing resistor of known value already in the circuit, by attaching the DMM to that resistor you created a parallel of resistors -- the DMM and that known-value resistor. So resulting resistance there changed thus the circuit is modified.In this universe, there is no way to do any measurement without some disruption. One can only minimize the disruption to the point of insignificance.Say you shine a light to look at where a tiny particle is, the photons are bouncing off the particle and hit your eyeball and you see where that particle is. But, if that particle is tiny enough, the photons are kicking the tiny particle around like an 8-ball hit by a bunch of cue balls so it's position is much disrupted. As one can imagine, if one just want to see something as big as an 8-ball by using photons, being kick around by photons is hardly a noticeable change. Any measurement disrupt, it is merely a matter of degree.One can never have enough DMM's. Personally, I think 3 is a good start, one can dedicate a pair to measure Current and Voltage simultaneously while still have another one to poke around other parts of a circuit.