Uh... but power is also equal to V*V/R. (Ohm’s Law). There is a good reason for having high voltage for long distance power distribution but I am not sure you have pointed out the correct reason. I did however, really enjoy your presentation.
But you only use V2/R when there is uniform voltage throughout... I reckon the voltage between two transmitters are the same but the voltage between the power source and first transmitter is less than the voltage between power source and second transmitter.. So you use V2/R when voltage is same throughout as in a parallel connection in domestic circuits..
You taught me about transformers so much better in less than 20 minutes than my lecturer who took 2 hours to teach this, without me understanding anything. *Thank youuuu*
i am a senior electrical engineer with 11 units (3 classes) left to complete and this has been more educational than anything any professor has ever taught me
I'm taking courses in electronics and sought out some RU-vid videos to break the monotony of reading. I greatly appreciate how you explain how Faraday's Law works with the transformers ... that was in my text but trying to read it just makes my head hurt. Your way of explaining helps a lot. Thanks!
Excellent question, dude! It's critical to note that when you use that equation for power lost in the line, V is the voltage DROP across the line. This is VERY often misunderstood. When you talk about a high-V line, you are referring to large V between the line and ground, but saying nothing about the voltage between one end and the other (hopefully the latter is small). You find V across the line by V = IR, so it is more direct to use P = I*I/R to find power loss on the line.
I love your electricity math and circuit videos, they are the best on the net. One thing to point out is, the power to feed homes in north america is 240v not 120v as most people think. It's a 3 wire system giving the option of 240v and 120v service to homes.
That's a super idea! I'm not sure where it would fit, but I do have so much more to say about electrical distribution. Thanks for the note, and thanks for watching.
I agree with you that cost and safety are factors, but you're confused about the voltage/current danger. Sure, current is what harms tissue, but a higher voltage power line (which is not current-limited) will ALWAYS cause a higher current through your fleshy body (that has a fixed resistance). You need to be WAY more careful around high-voltage lines than low-V lines. Again, that is exactly why they must be higher up and better protected from accidental bumping.
Wow, a lot of enthusiasm, it made learning about transformers more fun and interesting. It was a little bit fast paced for me, but overall it was a great video!
Even though english is only my second language, I was able to understand clearly what you said in this video and it really helped me out. Thank you for these informations!
YES! The iron in the core is laminated sheets to prevent eddy currents, which would significantly heat the iron and lower transformer efficiency. You can also make cores out of nonconductive iron-ceramic suspensions for the same reason.
Hey David! This came up on auto play after watching another video about transformers in a class I'm taking. And I said: "Hey I went to grade school with that guy!" Awesome indeed!
Not quite. Reread the previous post carefully, then continue: The current THROUGH the high-V line will be less than a low-V line that transfers the same power (because power transferred is IV). YOU DON'T CARE ABOUT THE CURRENT THROUGH THE LINE WHEN DECIDING WHETHER TO DIE OR NOT. The current through you is determined by I = V/R, where V is voltage between line and you (assuming you grabbed the dang wire) and R is YOUR resistance. However, Van De Graaffs are another story...
Oh, I understand your confusion. If I just hook up a battery to the primary coil of a transformer, that coil will experience a change in flux, right? The only problem is that the flux will approach a constant (saturated) value based on the steady-state current from the battery. That's why I mentioned a battery.
Your enthusiasm is awesome! Some critical feedback is that you don't go through an explanation of where the initial equations come from just some algebra on equations you just randomly pulled out of seemingly nowhere.
A nice sound bite, but it masks some important physics: Sure, current is what harms tissue, but a higher voltage power line (which is not current-limited) will ALWAYS cause a higher current through your fleshy body (that has a fixed resistance) 'cuz V = IR. You need to be WAY more careful around high-voltage lines than low-V lines. It's the current through YOU that matters, and that's determined by YOUR resistance and the voltage across you (from the line to ground, typically). DANGER!
Residential voltage is usually 120/240V. 120V line to neutral and 240V line to line, but I digress, you did an excellent job of explaining, and you kept it interesting.
Would be good if you could explain more about what delta phi is and how it is calculated and such like. Would be useful for someone like me who knows nothing about the mathematical side of understanding transformers!
I love how all the maths, theory etc. lead up to simple yet very stern and decisive declaration that the power grid was never meant to heat up the countryside.
One thing we also had to take into account was the transformer winding gauges (AWG) and resistance of each windings. We design these power supply (AC/DC) with an engineer and I was the Lab Technician.
Great thanks. What about the diodes? Do transformers emit heat because the coils impede the current flow? If so input power must be greater than output power.
Boy, I'm sure not an expert here, but I'll shoot from the hip. Maintaining safety raises costs while lower current lowers costs. You've also got to have step-up and step-down transformers at each end. So there's a sweet spot that depends on length of run and power needed. Hiring an engineer to find that sweet spot is probably a good idea. Maybe someone who knows more firsthand about power distribution will comment...
When the secondary circuit is open, my understanding is that current through the primary is negligible, resulting in very little power loss. Why? Wouldn't this behave like a simple inductor, with current flowing through primary windings similar to what happens when the secondary circuit is connected? Is this because, with the secondary windings disconnected, there is much greater inductance of a system where the electrons on the secondary side have nowhere to flow to?
some adapters use switching circuits - so the time ! power is gated ? ( whether a ups / uninterrupted power supply , or laptop charger ) sets the final output voltages .
Thanks that really helped alot ! Although why do we always use voltages to express the ammount of current we are transferring ? Why do we always say 120 volts instead of saying their equivalent in Ampere as current intensity .. is there a reason for that ?
Hi there. Great vid and info. I'm currently trying to build a transformer and was hoping you could help me. Specs show a tapped primary (0 - 10 - 210 - 230V) and six secondary windings (0 - 250V at 120mA / 0 - 35V at 20mA / a tapped low voltage winding 0 - 4 - 5 - 6.3 at 3A - 12.6V at 1A/ and three 0 - 6V at 50mA). No split bobbins just grounded copper tape between primary and secondary. I'm trying to figure out which winding order would suit this transformer best. Would you start with the primary, isolate and then just continue winding full layers from the lowest V winding to the highest? (for exemple the 0 - 6s first followed by the tapped winding, the 0 - 35 and finally the 0 - 250? Or does this type of setup requires more care in its order? I also trying to guess how the A decreases in that last tap 12.6V. Any idea? Cheers
Very cool story, love the ending XD So a question: I have some regular, 1:1, 4 pin transformer, but need some with a 5th pin for the ground-reference point.. Could I 'add' the 5th, centre tap, by just adding two equal resistors between positive and negative pin? I mean, at any given moment it's basically at V+ and V-, so by adding a Voltage Divider like that, could you 'hack' the ground pin into it? (It's for a Passive Ring Modulator, DIY synths and stuff)
Hi Doc thanks for the info. I tried to wind a trafo for a small inverter.It gave me high voltage on sec but could not drive a small motor even through a regulator.
This video is amazing, I think I'm gonna watch more of these coz it answers basic questions and puts it into context. AND you make it very interesting lol
I'm just getting into electronics and trying to learn as much as possible after learning about Nikola Tesla. I have some ideas, but don't know enough to apply them yet. If you use an a stable or flip flop circuit to supply the transformer would that work to create a stable voltage increase with the transformer?
so are you saying that electrical distribution systems are using higher voltage on power lines and less current, which causes more heat which causes electricity bills to be higher? when they could have higher current and lower voltage, which would cause less heat, which would be a lower electricity bill? thanks for the video....I am an electrician apprentice just learning some extra stuff.
Your videos are incredible. You gained one more subscriber. I am trying to learn more about transformers because I am moving to a country where they've got only 220v... All my current (pun?) devices are 110V North American, some are bivolt. Kitchen appliances are 110V and I am taking them with me. I took a look at transformers online. I don't trust any of them. I did my research and the one I found of a maybe, possibly, acceptable quality is the Kriegers... I have learned that heavy in weight, power supplies make for better, quality products. Somebody stated that the Kriegers are heavy... Anyway, my question is: If I have a device that is 300 watts, I am going to double or triple that amount in my transformer... I will get a transformer rated for 900 watts for example (not planning on powering hair dryers, microwave oven, etc). I know they are rated at that but don't really output that much because of heat, etc... HERE IS THE QUESTION (finally) Due to the transformer being a ''simple'' device, will the components, ie cheap brand, expensive brand make a real difference?
So I decided to make a custom transformer and do experiments with the ratios of the primary to the secondary winding, but...I don't know where to find certain materials such as: the e/i plates of iron-silicon and the spool or formwork. I was wondering if there are any hacks or ways to still make a transformer without certain materials, or just places i can buy these materials.
Thank you Doc Schuster so much!!! Your way of teaching is really good!! It helped me a lot. pls make a video for rectifier, transistor and amplifier. :)
at 10:48 you say that if we apply 1V emf in the secondary circuit we will get a 2V emf in the primary circuit, but since there is no AC, the flux won't be changing, and there should be no induced emf, right?
A Van de Graaff generator actually DOES have a lethal voltage and cause a lethal current to go through you. However, the current only exists for an infinitesimal time. Not enough time, hopefully, for your heart to stop or your tissue to be damaged. Don't try to explain both effects in the same sentence, though. In much of physics, you need to understand what your limiting or controlled factor is. I've been hit by my 500kV Van de Graaff more times than I'd like to admit, but I'm still here.
I m turkish highschool student we learned about transformers in school but i have never seen transformer before ... that was fun and you are the funniest teacher EVER 😂 All i learn in school is N1/N2=V1/V2☹️
Oooh...making sparks, eh? I'll leave this great problem as an exercise but ask you two in return: How do you think these two things will affect your time constant: 1) larger capacitance, and 2) larger load resistance. Good luck, and be sure to not shock through your heart.
