If you want a remote for something that will be underground or underwater, this is one of the few options that are practical. If you need a lot more range then you can get from this then you've got to add something like a floating repeater buoy that can receive an RF signal and translate it into a magnetic signal. One practical application I think of is an occupancy sensor for a pool or hot tub...
In this channel I have learned more electronics than studying my books. His explanations are unique in the web. He goes deep into the subject, something nobody does!
Tends to be a sign someone actually understands what they are saying as opposed to looking everything up prior to creating a video then explaining it as though you understood it all alone. Many creators seem to do this and it is quite obvious when you find them parroting basic stuff a quick Wiki search could teach you.
I'm a 30+year Diesel mechanic and I understand everything mechanical very well. Electrical is a different animal in that the vocabulary is like a bunch of clicking noise to me. I have to watch and listen very closely to absorb the information you so eloquently spout off in rapid fire. Hahahah. It's sinking in . Thanks for video and I find all this great, very very informative and helpful. Peace.
There appears to be an error on the receiver circuit diagram. The PNP output transistor is connected with its collector to rail not its emitter. I assume you intended the circuit to operate in a complementary configuration. As drawn, the output transistor permanently bias off.
Yeah that is in fact an error in the schematic. The software I'm using seems to automatically orient a PNP transistor with the collector/emitter swapped and I didn't notice it
6:03: Electric and Magnetic fields cannot exists alone, so you are effectively transmitting an electromagnetic wave (with a very big wavelenght). The induction phenomenon itself relies on the presence of electric field (Faraday Neumann Lentz law and Ampere Maxwell law). When you put the second coil near the first (the emitting coil), inside every infinitesimal slice of wire there is the electric field part of electromagnetic wave you are transmitting.
@@alexanderg-p3z A very pedantic answer is that it is not really a radio transmission system because it does not use radio waves to communicate. Maxwell's equations of the electromagnetic field show that there are two ways the energy of a perturbation leave the generating circuit; at close distance (up to 10 wavelengths) the so-called induced field dominates, which varies very rapidly in amplitude and behaves similar to the field between the coils of a transformer or between the stator and the armature of an electric motor / generator. Further away the electromagnetic energy travels as waves that drop in amplitude more slowly (proportional to the inverse square of the distance) towards the infinite horizons. In our case, for a carrier frequency of 69 kHz (approx. 4.35 km wavelength) at a few metres between the transmitter and the receiver, the signal doesn't act as a radio wave, so it is not a radio communication system.
my dad once taught me all of this when i was just a kid it has helped me understand cpus and so much more signal processing and all the cool ways to look at waveforms and encryption to man in the middle CB radios
Filter impedance is what the filter should see. Adding resistors (providing the impedance is what you thought), will each create a voltage divider cutting the voltage in half (6dB x2 =12dB) In other words remove the resistors and that will improve things. It would also be wise to design to the right impedance, which isn’t 1200 ohms.
Hearing aid induction loop systems are perfect for the function you want to achieve. The modules can be found at second hand stores or thrift stores because old peoples homes used to have installled those systems as well.
I suspect there is considerable scope for improvement to the receiver circuit sensitivity. It might be worth looking at the receiver circuits used in magnetic loop coupled hearing aids. Alternatively, you might consider looking at am diode receiver circuits that use an OOK decoder. This has the advantage of automatically adapting to the fall in the demodulated amplitude, allowing even millivolt signals to be decoded.
tried to do the same thing when I was 12 years old. used a many-turn coil and 9.6v ni-cd charger to send pulses and recieve them in audio amp with old fluorescent ballast with its core opened. I could make the speaker cradckle every time i turned on the coil up to about 8 meters of range
I used a similar circuit design for a plasma speaker with a flyback transformer. Without a large heatsink, the mosfet would desolder itself after less than a minute :)
Wow your projects are awesome. And it's really cool how you use mostly analog circuits. It's like black magic for us digital dummies:) One small thing: please do something with the background noise. In newer videos it's much better than in the old ones but still the noise puts some pressure on the ears an I think it deters some people. With this quality of the content your channel deserves much more views. Also it would be cool to see some deep dive into schematics that you design, for example component choises and more detailed explanation of the little details (maybe as a separate videos or text posts). So anyway big thanks to you for all this work it's really great.
many years ago I had a radio control book that detailed a similar system, but for the transmit coil it used a loop that ran around the area which you wanted to communicate - eg around the walls of a room, or around an area in a field. you could make the transmit loop as big as you wanted. i belive that then as long as the rx coil was inside the big loop (or up to about quarter to half the tx coil diameter outside the loop) then it would get the signal, so basically like a transformer but with an air core.
Would be very interesting to put the receiver in a faraday cage and compare range vs a regular radio. Lower frequency signals should get higher penetration in a faraday cage.
There is an old defcon talk where a super high power RFID scanner was demonstrated using almost the exact same system you have here. they built it into a backpack with a beefy battery for power source, and it was reading cards from over 35 feet away. a ground station can read cards even farther, with the rumor being that the US/Canadian border has readers that grab your info from over 100 feet away as you pull up to the crossing. Thankfully the banks caught up to RFID security problems eventually instead of continuing to pretend like RFID was bulletproof. most systems that use prox cards for access control require a pin or some other secondary method now. I remember my university had a single code that every student used to open every door back in 2007...
Here's an idea, connect the transmit coil to the TX of uart. Connect the smith trigger output to RX of uart on the receiver side. And serial print lots of different data. Cool stuff!
This will work under water at this distance as well, while the common multi MHz over the air RF will not work past a few cm. You can demonstrate this if you have a "body of water" near by (pool, lake ocean etc).
The output impedance of a filter should be as near as possible to the impedance of the antenna. The impedance of an antenna depends on frequency and your loop should have a very low impedance (maybe 4.7nanoOhm). The output impedance of your amplifier is also going to be extremely low unless you specifically designed it to have a higher impedance (which you did not). You will be better off just removing those two 1.2kOhm resistors. If you were using transmission lines of some sort between those components, you would need to match to them, but in this case, it is not necessary.
The Arduino UNO (R3) has an 8 MHz CPU clock. With your "nice" signal that means that you have 115.9 clock ticks per signal cycle. The Arduino Runtime eats up a lot of CPU cycles, especially if you use the provided functions, like pulseIn() digitalRead(), digitalWrite() etc. If you want a cleaner/ more finely resolved signal duration/frequency reading ( 14:15 ), you might want to: A) upgrade to something "faster", like a Raspberry Pi Pico (which runs at a 133 MHz clock) - finer resolution in timing your signal. B) operate your trusty UNO in "bare metal" mode, i.e. work directly with the hardware SFRs in code - less CPU wasted with the CPU in compiler framework housekeeping mode.
probably cascaded transistors will do good job at amplifying signals.and may be amplified high woltage coil as transmitter ;) ie something like high voltage high amps pulses
So, next an actual receiver with a mixer I guess? I recommend considering tayloe mixer circuit. Then sampling by ADC and digital filtering. That would be nice signal processing playground
On the receiver side, you may want to try looking into something called a regenerator circuit. Also known as a "regen receiver." The theory is to exploit positive feedback to make your tuning tank (coil and capacitor) extra sensitive. Basically, you "tickle" the receiver tank circuit just up to the point where it starts resonating, then cut it back down again and repeat this process over and over while observing the results. The key insight is that it will be easier/quicker to get the tank to resonate if there is an external signal "helping" it resonate. Or, said using the analogy, it's being tickled from both sides. Regen receivers have fallen out of vouge today, but back in the days of vacuum tube radio they were like what LoRa is today. Signal quality (bandwidth) suffered, but strength was greatly increased.
Can you make a transmission with both e and h fields? AKA double the bandwidth. I understand h field is lossy, but for close range WiFi it seems like it would be useful.
First, electric and magnetic fields are radiated together at distances above half a wavelength or so. Second, I believe your 2N3906s are drawn upside down -- possibly they are also installed backward making poor amplifiers. Third, the low input impedance of the 2N3904 greatly reduces the quality factor of your loop antenna. It might be worthwhile to put 1 k - 10 k in its emitter. Fourth, the low resistance (600 Ohm) in parallel with your pi filter also destroys its quality factor. Tank circuits have high impedance at resonance and need high impedance in parallel. I would use ~100 k instead of 1.2 k before the filter and the 1 k - 10 k emitter resistance is also recommended for the second stage. The second 1.2 k is then not needed.
As soon as a magnetic field varies, it becomes an electromagnetic wave. So I'm confused when you say at the beginning that you will transfer information with a magnetic field only
At 11:09, the PNP is not connected the correct way around. Can I suggest you label E, B and C on your circuits rather than the CADs lazy 1, 2 and 3? Looking at the circuit board at 13:51, you may have them inserted the correct PNP way around.
Your findings on the coil sizes are in line with my tests. One day I want to put a coil the size of my wall about 8ft circle, and see how far in the room I can transmit power to charge a phone wirelessly. I think it should charge just about anywhere in the room with a coil that large as the transmitter. The receiver needs to be tuned to the correct frequency but it can be a much smaller coil. Have you tried a really large transmitter coil like this? I think it would be a neat experiment. It could in theory be hidden within a wall and provide wireless power anywhere in the room. I found the size of the coil makes more difference than the actual input power. So theoretically one could take a 5watt large coil and get more out of it than a 10w small coil at the same distance. Hope that makes sense.
You would need to watch it doesn’t interfere with anything, this is only transmitting small amounts of power, but to charge a phone you would need quite a bit more power than is used here.
@@HyperspacePirate technically the first electrical wireless transmission was a light and a solar cell. They sent morse code. Ingenious right. ???But can we do this with lazers because light is more robust and punctures clouds to some degree. Second can we send data from one computer to another but instead of radio we use light without the fiber optics 😁😁😊😊
Hi, I love this video. One question : Could this circuit be used to transmit wireless electricity and light some kind of bulb other than a small led ? For example a small 12V halogen bulb. My doubt arises because it does not work as a continuous wave, but sending ¨pulses¨ or ¨signals¨. Best regards and thank you very much
That's sortof answered in the video segment about Transformers -> Crappy Transformers -> Awful Transformers at 5:14 :) ... but in short: sadly no. Unless you're simply looking at very close range, as used in induction chargers for phones. Otherwise the losses are too great at these frequencies of electromagnetism over any useful distance. Tesla dedicated much research into this back in the late 1800s, but very little other than "science" came from it. More recent research using microwaves has proven the theory as viable, but unless you _really really_ need to light that bulb wirelessly :), it's not something that's going to be easy, efficient, or arguably even particularly safe for useful power levels. For the various reaseach, applications, and limitations, you want to generally search for the topics of Microwave Power Transmission and/or Wireless Power Transfer methods.
The 200v diode is blocking the 75v diode from doing any work at all. Also the mosfets body diode is mot fast at all. So placing a faster one in parallel does not improve the body diodes opperation and will still close to late. The use of the 200v diode is good to block the fets body diode from conducting. But in this case the 75v diode's cathode has to connect to the 200v diodes anode. Anyway. Fun project.
Magnetic only? Guaranteed that loop is going to radiate RF at 69Khz; not very far since as you say it's a very short antenna for its wavelength. The receiver looks like an ordinary RF-tuned receiver. The air is not a xfmr core. The fact that the pulse is turned on with a short rise time; one would expect the laplace transform would show frequencies all over the place from this turn-on and from the decay. That could explain the noise. My guess is that this signal could be detected for miles with a VLF receiver with a large array cut for that frequency.
Love the science of this, but I still fail to see the practicality with the disadvantages you mentioned. Did you have a particular application in mind where this would make sense?
You don't think free unlimited energy is practical? Yes, I'm joking. My guess is this isn't intended to be practical. I think it was just an excuse to play with electronics and teach us about inductive coupling.
That D^-3.5, I am not convinced about this. As a radio amatuer I have a loop antenna I use on 7 - 21MHz bands. This type of anntenna is supposedly working on B field alone. It is 90cm diameter copper water pipe and open, with a tuning capacitor bridging the opening. At times, I can pick up stations from Europe (In Australia) that have an echo, meaning they have come to me via both the short path and the long path around the world. Transmit power might be as low as 1-10 watts, but typically might be 100W, maxxing out at 400W typically. With a receiver sensitivity of 0.1 to 1 uV (Signal to noise ratio means that any more is effectively pointless at these frequencies), call the distance 20,000km, it would seem by applying the distance rule you quote, then this is rather unlikely. More investigation is needed.
what about a long range bidirectional RC Transmitter and receiver? Try to make a rover that can be controlled at long range and be able to send pictures. Something like Perseverance rover
If you want a remote for something that will be underground or underwater, this is one of the few options that are practical. If you need a lot more range then you can get from this then you've got to add something like a floating repeater buoy that can receive an RF signal and translate it into a magnetic signal. One practical application I think of is an occupancy sensor for a pool or hot tub...
Interesting idea for some underwater transmission applications.
Hello. lets exchange contacts. I m also on that quest.
In this channel I have learned more electronics than studying my books. His explanations are unique in the web. He goes deep into the subject, something nobody does!
Tends to be a sign someone actually understands what they are saying as opposed to looking everything up prior to creating a video then explaining it as though you understood it all alone. Many creators seem to do this and it is quite obvious when you find them parroting basic stuff a quick Wiki search could teach you.
Not only a very clever circuit, but a superb explanation. Bravo, and thank you!
As an electronic engeneering student, I can say one of the best video I've seen on UA-cam
I love it when you show the circuits and describe how it works!
I'm a 30+year Diesel mechanic and I understand everything mechanical very well. Electrical is a different animal in that the vocabulary is like a bunch of clicking noise to me. I have to watch and listen very closely to absorb the information you so eloquently spout off in rapid fire. Hahahah. It's sinking in . Thanks for video and I find all this great, very very informative and helpful. Peace.
I love your ture engineering, rare quality on UA-cam!
allthough i know a bit about electronics, I don't understand even half of what he says, but I still love these videos. so relaxing.
First seconds of the video and I'm already hooked because of the KSP music, great choice
There appears to be an error on the receiver circuit diagram. The PNP output transistor is connected with its collector to rail not its emitter.
I assume you intended the circuit to operate in a complementary configuration. As drawn, the output transistor permanently bias off.
Yeah that is in fact an error in the schematic. The software I'm using seems to automatically orient a PNP transistor with the collector/emitter swapped and I didn't notice it
Well he noticed well played nigel
@@HyperspacePirate Hey, also your caps are labeled with the unit Henries on your first schematic. Awesome video!
6:03: Electric and Magnetic fields cannot exists alone, so you are effectively transmitting an electromagnetic wave (with a very big wavelenght). The induction phenomenon itself relies on the presence of electric field (Faraday Neumann Lentz law and Ampere Maxwell law). When you put the second coil near the first (the emitting coil), inside every infinitesimal slice of wire there is the electric field part of electromagnetic wave you are transmitting.
It is in principle a radio transmitter / receiver, isn't it?
@@alexanderg-p3z A very pedantic answer is that it is not really a radio transmission system because it does not use radio waves to communicate. Maxwell's equations of the electromagnetic field show that there are two ways the energy of a perturbation leave the generating circuit; at close distance (up to 10 wavelengths) the so-called induced field dominates, which varies very rapidly in amplitude and behaves similar to the field between the coils of a transformer or between the stator and the armature of an electric motor / generator. Further away the electromagnetic energy travels as waves that drop in amplitude more slowly (proportional to the inverse square of the distance) towards the infinite horizons. In our case, for a carrier frequency of 69 kHz (approx. 4.35 km wavelength) at a few metres between the transmitter and the receiver, the signal doesn't act as a radio wave, so it is not a radio communication system.
my dad once taught me all of this when i was just a kid it has helped me understand cpus and so much more signal processing and all the cool ways to look at waveforms and encryption to man in the middle CB radios
Filter impedance is what the filter should see. Adding resistors (providing the impedance is what you thought), will each create a voltage divider cutting the voltage in half (6dB x2 =12dB)
In other words remove the resistors and that will improve things. It would also be wise to design to the right impedance, which isn’t 1200 ohms.
Thank-you. Your explanations are some of the best I have ever encountered - Awesome. And the projects are excellent as well.
Awesome demonstration that combines learnings from undergrad circuits + electromagnetics
Hearing aid induction loop systems are perfect for the function you want to achieve. The modules can be found at second hand stores or thrift stores because old peoples homes used to have installled those systems as well.
Video on rotary transformer please -> for magnetless brushless axial flux motors
Not sure of the 'why' of it, but the coolness factor coupled with description of 'how' is 10/10
I suspect there is considerable scope for improvement to the receiver circuit sensitivity. It might be worth looking at the receiver circuits used in magnetic loop coupled hearing aids.
Alternatively, you might consider looking at am diode receiver circuits that use an OOK decoder. This has the advantage of automatically adapting to the fall in the demodulated amplitude, allowing even millivolt signals to be decoded.
his smarts are under rated... you tube gods and developers give this nerd a million followers
this might be useful for underwater applications
tried to do the same thing when I was 12 years old. used a many-turn coil and 9.6v ni-cd charger to send pulses and recieve them in audio amp with old fluorescent ballast with its core opened. I could make the speaker cradckle every time i turned on the coil up to about 8 meters of range
thank you for the amazing explanation.... probably the first video in which bi understood everything.
I used a similar circuit design for a plasma speaker with a flyback transformer. Without a large heatsink, the mosfet would desolder itself after less than a minute :)
Wow your projects are awesome. And it's really cool how you use mostly analog circuits. It's like black magic for us digital dummies:) One small thing: please do something with the background noise. In newer videos it's much better than in the old ones but still the noise puts some pressure on the ears an I think it deters some people. With this quality of the content your channel deserves much more views. Also it would be cool to see some deep dive into schematics that you design, for example component choises and more detailed explanation of the little details (maybe as a separate videos or text posts). So anyway big thanks to you for all this work it's really great.
Analog circuits feel genuinely impossible at times, but they are so satisfying to pull off.
many years ago I had a radio control book that detailed a similar system, but for the transmit coil it used a loop that ran around the area which you wanted to communicate - eg around the walls of a room, or around an area in a field. you could make the transmit loop as big as you wanted.
i belive that then as long as the rx coil was inside the big loop (or up to about quarter to half the tx coil diameter outside the loop) then it would get the signal, so basically like a transformer but with an air core.
Wow, that's very clever. I use the 555 and 556 in model rockets for event execution they have so many uses
Would be very interesting to put the receiver in a faraday cage and compare range vs a regular radio. Lower frequency signals should get higher penetration in a faraday cage.
There is an old defcon talk where a super high power RFID scanner was demonstrated using almost the exact same system you have here. they built it into a backpack with a beefy battery for power source, and it was reading cards from over 35 feet away. a ground station can read cards even farther, with the rumor being that the US/Canadian border has readers that grab your info from over 100 feet away as you pull up to the crossing.
Thankfully the banks caught up to RFID security problems eventually instead of continuing to pretend like RFID was bulletproof. most systems that use prox cards for access control require a pin or some other secondary method now. I remember my university had a single code that every student used to open every door back in 2007...
Here's an idea, connect the transmit coil to the TX of uart. Connect the smith trigger output to RX of uart on the receiver side. And serial print lots of different data. Cool stuff!
Nice project , you can add a heatsink to the MOSFET. The best component in the project is the variable capacitor.
This will work under water at this distance as well, while the common multi MHz over the air RF will not work past a few cm. You can demonstrate this if you have a "body of water" near by (pool, lake ocean etc).
yes the video popped up in the right time i really needed a good simple circuit for transmitting, love it❤❤
good engineer❤🎉good guy that is how the great start
The output impedance of a filter should be as near as possible to the impedance of the antenna. The impedance of an antenna depends on frequency and your loop should have a very low impedance (maybe 4.7nanoOhm). The output impedance of your amplifier is also going to be extremely low unless you specifically designed it to have a higher impedance (which you did not). You will be better off just removing those two 1.2kOhm resistors. If you were using transmission lines of some sort between those components, you would need to match to them, but in this case, it is not necessary.
Thank you for your good content, if possible, prepare a project about Lectenna.
Love the build, but with that music you're missing a few Kerbals!
Brillante trabajo excelente explicación! gracias
The Arduino UNO (R3) has an 8 MHz CPU clock. With your "nice" signal that means that you have 115.9 clock ticks per signal cycle. The Arduino Runtime eats up a lot of CPU cycles, especially if you use the provided functions, like pulseIn() digitalRead(), digitalWrite() etc. If you want a cleaner/ more finely resolved signal duration/frequency reading ( 14:15 ), you might want to:
A) upgrade to something "faster", like a Raspberry Pi Pico (which runs at a 133 MHz clock) - finer resolution in timing your signal.
B) operate your trusty UNO in "bare metal" mode, i.e. work directly with the hardware SFRs in code - less CPU wasted with the CPU in compiler framework housekeeping mode.
1:40 caps in henries. Cool
Useful information, thanks for explaining this so well. KUDOS
probably cascaded transistors will do good job at amplifying signals.and may be amplified high woltage coil as transmitter ;) ie something like high voltage high amps pulses
Fascinating that instead of filming plugging in the device you would reverse a shot of unplugging it
Very clear explanation! Thanks!👍
This is exactly I was looking for 👀
Really cool project. Thanks
Excellent work
Really GREAT WORK ❗
But - WHY ❓
Do you need to transfer RC Signals to a submarine?
So, next an actual receiver with a mixer I guess? I recommend considering tayloe mixer circuit. Then sampling by ADC and digital filtering. That would be nice signal processing playground
Thanks bro i do same experimemt a year before with new idea power transfer with audio transfer.
your project was good , i love it . please what is the max range in meters
The diagram and all things u said after that I completely lost it mayb this Is for good bright electrical backgrounded people to understand and build.
You just have a new subscriber
On the receiver side, you may want to try looking into something called a regenerator circuit. Also known as a "regen receiver."
The theory is to exploit positive feedback to make your tuning tank (coil and capacitor) extra sensitive. Basically, you "tickle" the receiver tank circuit just up to the point where it starts resonating, then cut it back down again and repeat this process over and over while observing the results. The key insight is that it will be easier/quicker to get the tank to resonate if there is an external signal "helping" it resonate. Or, said using the analogy, it's being tickled from both sides.
Regen receivers have fallen out of vouge today, but back in the days of vacuum tube radio they were like what LoRa is today. Signal quality (bandwidth) suffered, but strength was greatly increased.
69kHz nice!
11:14 since it's a current amplifier wouldn't the gain be 96Db because the equation for current gain in decibels is 20Log(AI)
Thankyou for sharing this greate informational video
well done and explained.
it would be interesting to see how far this would work underwater
Can you make a transmission with both e and h fields? AKA double the bandwidth. I understand h field is lossy, but for close range WiFi it seems like it would be useful.
Would you be able to use the signal you created in the distance to to retract objects like magnets from that far away ?
no.
First, electric and magnetic fields are radiated together at distances above half a wavelength or so. Second, I believe your 2N3906s are drawn upside down -- possibly they are also installed backward making poor amplifiers. Third, the low input impedance of the 2N3904 greatly reduces the quality factor of your loop antenna. It might be worthwhile to put 1 k - 10 k in its emitter. Fourth, the low resistance (600 Ohm) in parallel with your pi filter also destroys its quality factor. Tank circuits have high impedance at resonance and need high impedance in parallel. I would use ~100 k instead of 1.2 k before the filter and the 1 k - 10 k emitter resistance is also recommended for the second stage. The second 1.2 k is then not needed.
Would this work to transmit through media that block radio, like water? Could this be used to communicate with an RC submarine, for example?
As soon as a magnetic field varies, it becomes an electromagnetic wave. So I'm confused when you say at the beginning that you will transfer information with a magnetic field only
The LC filter capacitor has a value of 3.3 mH?
Say whaaaaaaat? Haha I love it where have you been hiding this is some serious electrical engineering going on.
Thank you so so much
Something wrong with the 2N3906. The emitter is connected to negative. It's a PNP device, and the emitter would normally connect to positive.
Magnetic fields can go trouhg any material without being stopped at all, only ANOTHER magnetic field exacly the same properties
can reppel It.
At 11:09, the PNP is not connected the correct way around. Can I suggest you label E, B and C on your circuits rather than the CADs lazy 1, 2 and 3?
Looking at the circuit board at 13:51, you may have them inserted the correct PNP way around.
love your videos!
What kind of glue you usually use for plastic parts?
What's up with the capacitors labeled in Henry?
Your findings on the coil sizes are in line with my tests. One day I want to put a coil the size of my wall about 8ft circle, and see how far in the room I can transmit power to charge a phone wirelessly. I think it should charge just about anywhere in the room with a coil that large as the transmitter. The receiver needs to be tuned to the correct frequency but it can be a much smaller coil. Have you tried a really large transmitter coil like this? I think it would be a neat experiment. It could in theory be hidden within a wall and provide wireless power anywhere in the room. I found the size of the coil makes more difference than the actual input power. So theoretically one could take a 5watt large coil and get more out of it than a 10w small coil at the same distance. Hope that makes sense.
funny I was thinking of putting one behind the drywall hahah
You would need to watch it doesn’t interfere with anything, this is only transmitting small amounts of power, but to charge a phone you would need quite a bit more power than is used here.
Then that transmitter will charge you instead of phone in the room. :)
Try using an MRI machine next :)
IN4148 for 75V? the last one I measured was closer to 110.
Hello,
Can I use a HF inverter module to feed a HF pulse wave directly to the coil instead of the transmitter circuit?
Solar panel and flashlight works pretty good for sending wireless signals with minimal stuff.
Yeah, at some point i wanted to do that with a laser
@@HyperspacePirate technically the first electrical wireless transmission was a light and a solar cell. They sent morse code. Ingenious right. ???But can we do this with lazers because light is more robust and punctures clouds to some degree. Second can we send data from one computer to another but instead of radio we use light without the fiber optics 😁😁😊😊
Damn, you could use this to transmit the base line of a dubstep song and watch grandpa breakdance to it
The amplifier stages shown in that receiver are wrong,
they cannot work since the respective first transistor
has no collector current at all.
Hi, I love this video. One question : Could this circuit be used to transmit wireless electricity and light some kind of bulb other than a small led ? For example a small 12V halogen bulb. My doubt arises because it does not work as a continuous wave, but sending ¨pulses¨ or ¨signals¨.
Best regards and thank you very much
That's sortof answered in the video segment about Transformers -> Crappy Transformers -> Awful Transformers at 5:14 :) ... but in short: sadly no.
Unless you're simply looking at very close range, as used in induction chargers for phones. Otherwise the losses are too great at these frequencies of electromagnetism over any useful distance. Tesla dedicated much research into this back in the late 1800s, but very little other than "science" came from it.
More recent research using microwaves has proven the theory as viable, but unless you _really really_ need to light that bulb wirelessly :), it's not something that's going to be easy, efficient, or arguably even particularly safe for useful power levels.
For the various reaseach, applications, and limitations, you want to generally search for the topics of Microwave Power Transmission and/or Wireless Power Transfer methods.
This example is not antenna ? Just transformer coupling ?
The 200v diode is blocking the 75v diode from doing any work at all.
Also the mosfets body diode is mot fast at all. So placing a faster one in parallel does not improve the body diodes opperation and will still close to late.
The use of the 200v diode is good to block the fets body diode from conducting.
But in this case the 75v diode's cathode has to connect to the 200v diodes anode.
Anyway. Fun project.
Hi. Love your videos! Just curious where did you acquire electrical engineering knowledge from?
Magnetic only? Guaranteed that loop is going to radiate RF at 69Khz; not very far since as you say it's a very short antenna for its wavelength. The receiver looks like an ordinary RF-tuned receiver. The air is not a xfmr core. The fact that the pulse is turned on with a short rise time; one would expect the laplace transform would show frequencies all over the place from this turn-on and from the decay. That could explain the noise. My guess is that this signal could be detected for miles with a VLF receiver with a large array cut for that frequency.
So cool
What software are you using to design and test/model your circuits?
Love the science of this, but I still fail to see the practicality with the disadvantages you mentioned. Did you have a particular application in mind where this would make sense?
You don't think free unlimited energy is practical?
Yes, I'm joking. My guess is this isn't intended to be practical. I think it was just an excuse to play with electronics and teach us about inductive coupling.
Dont worry, most everyone fails to see the practicallity of most scientific technologies and those that dont make lots of $$
One of the first things that I can think of that it can be used for, is controling devices under WATER where RF FEARS to go.
There's is a jurassic park quote for this
No vision for IR and congested or unlicensed RF.
9:18, nice
Now you need to plug it to your TV and see if you manage to lose it under the couch as normal TV remote :D
That D^-3.5, I am not convinced about this. As a radio amatuer I have a loop antenna I use on 7 - 21MHz bands. This type of anntenna is supposedly working on B field alone.
It is 90cm diameter copper water pipe and open, with a tuning capacitor bridging the opening.
At times, I can pick up stations from Europe (In Australia) that have an echo, meaning they have come to me via both the short path and the long path around the world. Transmit power might be as low as 1-10 watts, but typically might be 100W, maxxing out at 400W typically.
With a receiver sensitivity of 0.1 to 1 uV (Signal to noise ratio means that any more is effectively pointless at these frequencies), call the distance 20,000km, it would seem by applying the distance rule you quote, then this is rather unlikely.
More investigation is needed.
Bro, teach us how to amplify rf 433 MHZ transmitter.
what about a long range bidirectional RC Transmitter and receiver? Try to make a rover that can be controlled at long range and be able to send pictures. Something like Perseverance rover
wow awesome bro
frequency is the key
Are you using KiCad to design your circuits?
Next, please- RFID and NFC at a distance by magnetic field!
Well if you want to just send simple bytes its possible but when you want real data to be send you need a special circuit
@@309electronics5 why is that? What makes this system inadequate for "real data"
Can you do Arduino complex coding ...
Than i have a question ...
Could you pass usb data using something like this
Bro, u r making it hard for me .u r making it hard for me .