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Wow, what a brilliant video. I wish I had had a teacher like you when I was at school in the 70s. Anybody remember the flashing roadworks beacons? , Had a few of them in my younger days, took out the pcb and put the beacon back so it just stayed on permanent. Made many flashing gadgets with this pcb, even stepping up to flashing a 240v for a mates party. Didn't have a lot but we enjoyed what we had.
I think there's a lot of engineering minded people out there who are guilty of stealing those roadwork beacons to see how they work. Personally I was surprised to find a giant battery inside, that was simply made of multiple small batteries linked together.
The road work flashers are nothing new. My man has made his own flasher without stealing one off of a construction cone. His own design fully on his own.
Thank you for this video. I have this components on university, but without your videos and real life examples and projects, I would only forget all what I was teached. You are making a difference in understanding and learning. Thank you very much for your dedicated work.
This is the only channel resource that does amazing work at explaining what components are used and why. This channel has helped me in my guitar amp circuit design project.
Great tutorial of an LED light chaser. I have made this circuit before, you can use 2n3904's too. Also with a large number of LEDS in the chain you can experiment with connecting a wire across several LED to send a signal to another transistor not in following the main loop. It creates interesting chase patterns depending on where you connect it.
This is the best description and demonstration of capacitors I’ve seen. Everyone explains how they are built but no one provides concrete examples. Thank you so much.
I wanted to get into circuit building but never knew where and how to start. Although big books on these matters are valuable, your easy to process and do format fits my short attention span so much more :) Thank you for this!
Check Amazon or other retailer for a breadboard starter kit; there are tons of options out there, anywhere from $20 on up. There are some excellent books for self-teaching as well, but realistically it's easier to follow along with a good instructor on RU-vid.
It can flow through either and they will both actually get some power as soon as the battery is connected, I just had to choose a way to visually explain the circuit so I went with this route. The resistor values will never be exactly the same, whichever one has the slightly lower resistance will get slightly more electrons and that will start the process
@@EngineeringMindset Yeah, that was an important thing that should have been mentioned in video, and yet even that answer wasn't complete. To be complete for that question, you should have also mentioned that as soon as the transistor which *happens* to open first (due to the mentioned dissimilarities between components), it immediately pulls down the base voltage of the other transistor, keeping it shut until the capacitor charge has been built up to open it, in turn pulling down the base voltage of the first one, and cycle repeats. While this video is a very respectable attempt to make a good explanation, it also contains other errors, omissions, and inconsistencies causing a lot of headaches for the target audience - unfamiliar on electronics: - 0:55 you should have said "in series" instead of "across", which is inaccurate expression and tends to imply rather an led connected in parallel with the transistor. I see, you said "led circuit", by which you thought about the circuit of led, resistor, battery, and their wires, which as a "circuit unit" is indeed connected across - alas.. essentially parallel - with the transistor. But beginners cannot get that, they don't differentiate the meaning of your "led circuit" from led, and they intuitively think the "across" just as "in parallel with". - You are showing demo videos on transistor operation, in which you are feeding base current directly with a battery. You may not do that! Transistor BE junction always needs a current limiting resistor if fed by constant voltage! Otherwise it gets destroyed, ie. very same applies there than you mentioned with leds! - 2:57 You omitted very relevant "also" word before the word "causes". Such omission causes incorrect implication that it would be the current through the led and its series resistor which causes the "electrons to be pulled into capacitor". But it is not, the capacitor "pulling" is caused directly by the previously mentioned opening of the transistor, to which you could have referred by a word "also". Ie. it is the very same cause which also(!) causes the led and resistor current to flow. The same word omission was when explaining the other side when its time came. - When driving several discrete leds from same source, you should never connect them directly parallel, because very slight differences between their forward voltage characteristics may cause huge imbalance in distribution of the current between leds, possibly destroying one and after it the rest will have yet hugely more current and be certain to be destroyed. This is actually quite a common cause for premature failures of cheapo led lighting products. Every parallel-connected discrete led should each have a separate current limiting resistor.
It's been a long time since I did the circuit building. It's fun to do this and you can build some interesting projects. The math for the circuit components is what I forgot from long ago. Thank you for this.
Time you got back into making hobby circuits I think. Great fun. I tried to go lightly on the math in this video, replacing the parts with trial and error to make it more visual
Some Websites have an LED Resistor Calculator that do that for you. I also use one of these although I can use the (R = U / I) Formula. It's just as fast as calculating yourself.😄😄😁😁
It is very simple, and no math is needed to figure it out. 3v 100ohm 5v 330ohm 7v 470ohm 9v 620ohm 12v 1.5kohm And so on. Just remember voltage vs current is all you need. First rull of thumb is, always find the l.e.d specks when you purchase, forward voltage, and current. You will find that what I said is approximately to the correct value to a standard, 2.8v 15 to 20 ma l.e.d
HOLLY COW! So much info for a guy who has been fascinated with electronics, but never really took any in-depth courses on it (just come fundamentals long, long ago). I really appreciate your videos. I will be going back over this video; and also find the one that precedes this one. Thank you.
This is surely the best explanation to anyone of pretty much any level of knowledge in electronics to correctly grasp the major components of what such circuitry is actually meant for and how you can benefit from the properties of these components. Thank you so much good sir.
This video has gave me such a good understanding of electronic circuits. Knowing how each component works is cool but seeing how they can be cleverly arranged to do what you want is really amazing to me. You explain everything very well. Excellent video
Few years ago I have purchased on aliexpress a soldering training pcb in the shape of small flashing led Christmas tree, and i have always wondered how it works. Guess I learned it today. Thanks!
the only thing i can't understand is how the current delay occurs when the circuit is ideal, please clarify this one thing all of your videos were perfect❤ , this is the only doubt which have been in my mind
Excellent project, I think I would switch it up a bit and using a AC to DC wall wart as the power supply as it seems they come with anything electronic and I have a bunch of them of varying voltages lying around, and one of them would plug in directly to my tree lights and get it going without the need for a battery so I can feel more comfortable leaving it on all day long. As an aside, I do want to personally thank you for your videos, I teach an intro physics E&M lab class and have been doing so remotely for the past 2 years and for a few of the labs I do link directly to some of your videos (resistors, diodes, capacitors, etc) as part of the lecture (not done live) as I think the visuals that you have are absolutely perfect, and way better than what I could do, also a number of my students are EE students so I'm sure your other videos that are not related to what I'm doing are relevant to them as a nice way to teach them. So indirectly your work has helped me teach others (I hope), so thank you.
Crazy that this is a completely analog circuit; no controllers or computers operating the lights. The capacitors act as delay sensors in this configuration. Makes one wonder if this is how old neon lights worked in the early part of the 20th century. Very fascinating circuit.
3:08 I do not fully understand why the current flows to the transistor number 2 base only when the capacitor 1 is charged it could flow there immediately. Can someone explain it to me? :)
Maybe I'm wrong but here is what I understood after a first view of the video : The current is not going through the first capacitor because the first loop is open by the first transistor, so it goes to directly to the second loop, and this will power the second LED while charging the second capacitor. Once the second capacitor is fully charged the current will flow to the first transistor which will close the first loop and turn on the first LED while charging the first capacitor. Once the first capacitor is fully charged it will active the second transistor and then it cycle like this again an again.
The base-emitter junction of the NPN transistor acts like a diode. Significant current will not flow across it until the forward voltage of 0.7V has been reached. When transistor 1 is fully switched on, its collector is pulled close to ground voltage. If capacitor 1 is in a fully discharged state, then base of transistor 2 is also close to ground. But notice the orientation of those capacitors? Why is the negative side connected to the bases of the transistors? This explanation has actually been simplified. What really happens during the charge/discharge cycle is that the base of the transistor in an astable multivibrator will sometimes go below ground voltage. For a more complete explanation of this circuit see RSD Academy's channel
I think the only change I'd make for the circuit board would be to round the edges of the star-shape to make it a bit friendlier for kids to be around (in case it falls off of the tree, you don't want a sharp projectile). Thank you for the great walkthrough, your videos have been extremely helpful in learning how to do electronics design!
Stop resisting. But seriously, they are just limiting how many electrons can flow through the branch of the circuit. That makes the capacitor charge slower and also stops too many electrons passing through the LED and burning it out
I ve predicted how it works by just thinking about it I ve learned important stuff from your videos thx for doing em you really helped me *sadly I can't support u with money but I hope my words make u feel good you do rlly good content*
Good job Buddy, your channel is very interesting. I don't think I'll be able to create your star, however, but I at least learn some basics in electronics. Thanks to you! :)
Tip: Solder the (AE) aluminum electrolytic capacitors flush with the board. Per IPC-610, I recall if they have to be raised they need some kind of reinforced support on the leads. Whether by creating a spring kink or applying RTV under the leads. Sorry I see it so much as an EE on end product and it makes me want to head slap. Think about those tiny skinny leads holding that big belly cap. Makes it easier to accidentally bend a few times max and that’s it.
Nice circuit I also put a variable resistor or potentiometer between the all the resistors going to the negative of the capacitor and the power rail and made its speed variable
Thank you very much for your interesting videos. When I was a kid in the seventies I build a little FM transmitter that was fitted in a matchbox, it had a range about 200 meters, It was a building kit that I ordered from an ad in a hobby magasin. I would love to build a simulare kit again 😎 Do you have any sources?
Check on amazon, there are simple solder kits that are just like this and fantastic for kids! Did a few in high-school, some 15 years ago. Had a Christmas tree shaped one that did all the lights
In digital terms, it is Ring Counter, multiple odd numbers of inverters are connected in a loop to drive LEDs. Also, the circuit has very poor thermally stable timing.
Key notes for me: when one capacitor is charging, the other is discharging. The direction of the discharge follows the direction of the flow of current towards the (- side) of battery.
All good but I think you should have stuck to the AA batteries for longer battery life I don't think the button cell was a good choice, but the rest was very good, thanks haven joined your channel. Bob in the UK
Minecraft redstone! Visualizing the oscillation of current in these circuit's help's me to understand the math. Visualization in the mind's eye is extremely important to learning.
Nice video, but I have to stress that an astable multivibrator is NOT a flip-flop. A key aspect of a flip-flop is that it can be flipped to one state and holds this state until you deliberately flip it to another state. It is right that a flip-flop is a multivibrator, but a bistable or n-stable multivibrator (where n is the total number of states). An astable multivibrator is usually described as a relaxation-oscillator.
@@EngineeringMindset They are very similar circuits yes, but for a flip-flop you also have to replace the capacitors with resistors and remove the corresponding pull-ups that no longer has a purpose. This will keep it stable, even if none of the set-switches are closed.
3:17 Which resister is R1, and which resister is R2, and which resister is R3, and which resister is R4? But, thanks for identifying the values of said components.
Hey I read in my textbook yesterday that because a MOSFET transistor is symmetric, you can swap the source and drain without changing the characteristics. I was wondering if this is true in practice? Can I take any MOSFET IC with 3 terminals and do this? Or do the integrated circuit forms that we use have extra components that actually designate the S, G, and D terminals?
Not sure if you have already made a video on Crankcase pressure regulators (CPR) and evaporator pressure regulators (EPR) within a refrigeration system if not, could you kindly. Thank you for your content it’s been a huge help in learning about HVAC
