Energy harvesting from radio waves

It is easy to harvest energy from medium wave (530kHz to 1700 kHz) radio signal. If you are located close to AM radio station you can get several watts of power. which is sufficient enough to charge your cell phone and drive several LED lams.
The presentation file link:
drive.google.com/file/d/14f-P...

[@webpa]

Built an "RF-Powered Radio" back in the 1950s from an article in a now-extinct hobbyist magazine. Single CK-722 (very expensive) transistor amp, 1N34 detector, roughly 50 ft long wire antenna - all in the attic. It drove a speaker at a clearly-audible level. When the family sold the house 50 years later, it was still up there in the attic, working just fine.

[@technologyforyou5976]

Good to know your experience. Thanks for watching

[@Cinncinnatus]

was just going to say oh look something new 'oh yeah thats not right' blowing the dust off their crystal radio oh look a radio with no power source but the RF waves...

[@prte100]

Funfact, the CK722 is today called the first "low cost" , see the wikipedia article: The CK722 was the first low-cost junction transistor available to the general public. It was a PNP germanium small-signal unit. Developed by Norman Krim, it was introduced by Raytheon in early 1953 for $7.60 each; the price was reduced to $3.50 in late 1954 and to $0.99 in 1956. Norm Krim selected Radio Shack to sell the CK721 and CK722 through their catalog. Krim had a long-standing personal and business relationship with Radio Shack.[1] The CK722s were selected "fall out" from the Raytheon's premium-priced CK721 (which are fallouts from CK718 hearing-aid transistors).[2] Raytheon actively encouraged hobbyists with design contests and advertisements.[3][4]

[@kenmoulton5221]

I made one of these when I was drinking with my buddies in my 20's. Such a fun project!

[@rikardlalic7275]

Interestingly well suited is the legal aspect of such a device. As an ordinary radio receiver in concept, it is actually legal. It does not consume more broadcasted power than a legaly obtainable audio receiver and makes no unprediced or unanticipated load and influence to the broadcasted RF signal.

[@technologyforyou5976]

Thanks for watching and your comments. In some countries, it is not legal to harvest energy from radio waves, but in most of the countries there is no restrictions. As radio waves are radiated energy whatever ways we use it on the broadcaster side it does not cost any extra electric bill. On the other hand reactive power harvesting is illegal as that draws power from the main line. Reactive power harvesting involves capacitive or inductive power drain by placing a coil or metal piece close to the power line

[@Peter_S_]

There was a U.S. Patent issued for this idea a number of years ago. The person who filed the patent also patented noise canceling headphones.

[@technologyforyou5976]

Good to know. Thanks for watching

[@WSmith_1984]

Nikola Tesla's dream realised ultimately... That man was way ahead of his time. Great video, thanks for sharing 👍

[@technologyforyou5976]

Thanks for watching. Nicola Tesla's dream is yet to be achieved fully, in future we should certainly see some success in that direction.

[@yeroca]

Tesla knew that "Hertzian waves", as he called them, could not be utilized to carry much power. We know these as EM waves these days, and that's what's being used here, and as you can see, the power is pretty minimal. However, in another sense, sunlight is a form of EM waves and are of much higher power than typical radio waves, and we certainly get a lot of power from solar panels.

[@technologyforyou5976]

@@yeroca Yes, of course solar power harvesting is certainly way better than this. Just out of curiosity I do experiment, and shared my experience.

[@yeroca]

@@technologyforyou5976 That's great! I just wanted to draw a distinction between Tesla's dream power transmission method and what you're making use of here. Thanks for the reply.

[@electricAB]

Thank you very much for sharing and for your clear commentary.

[@technologyforyou5976]

Thanks for watching

[@kabandajamir9844]

The world's best professor thanks

[@technologyforyou5976]

Thanks for watching

[@willyjensen8595]

I'm pleased that you said "idea", if you had diodes which could turn on with just a few nanovolt, then you a case.

[@technologyforyou5976]

Thanks for watching

[@glenmartin2437]

Thank you.

[@user-hw6bl4wg6o]

Subscribed 😊, by the way wonderful setup in the background sir..thanks for useful contents keep doing keep growing.

[@technologyforyou5976]

Thanks very much for watching subscribing and good comments.

[@shawncalderon4950]

Nice work!

[@technologyforyou5976]

Thanks for watching

[@newmonengineering]

I just found your channel, you are doing well. I know making videos is not easy. Appreciate the effort. Its nice to see others and their projects to get ideas from. I have built a few of these myself. I have also been doing something similar but different with static electricity in the air. Turns out you can collect energy from the atmosphere with just an antenna, but to get more from it you can break and make the circuit rapidly. So you could build one that oscilates at the speed of the RF of the station through a transformer and there for drive both the RF reciever and the static electricity from the air to get substantially more power. You may try that. I don't know the best circuit as i have only just started playing with it but i did get it working a bit.

[@technologyforyou5976]

Thank you very much indeed for watching and your comments. Yes, I also have interest in static electricity. Hope to work on that direction soma day. Thanks again

[@spatoinker8743]

Hey! Do you also watch thinking and tinkering? I am also extremely interested in these types of projects and specifically static energy harvesting.

[@technologyforyou5976]

I just had a brief look at Thinking and Tinkering, these are nice. Thanks for telling me about it. I also hope to do something to harvest static energy in future@@spatoinker8743

[@fcpro9587]

Thank❤❤❤❤

[@googletropcurieux8670]

Very interesting Ty

[@technologyforyou5976]

Thanks for watching

[@jameshead9119]

There are two other sources as well one is high tension power towers where power is constantly leaking into aria and the sun also generates masses amount of power while most is shielded By the vanhallen belt quite a bit still makes it down to earth and was a constant problem in the past by the constant crackling in the back ground that could get really bad in sun spot season

[@googletropcurieux8670]

Very cool to know. Millennials didn’t do that kind of thing for the most part

[@leondeco4835]

Thanks for video

[@technologyforyou5976]

Thanks for watching

[@3D_Printing]

It's again the law

[@hartyguyton3800]

I wish you could elaborate more about the wire (antenna ) its features also earth line thanx for sharing

[@technologyforyou5976]

The antenna is a very simple one. Just one long wire, AWG 22, plastic jacket ,75 feet long. It is usually called a "L-Type" Antenna or monopole antenna. The GND is just connected to powerline Earth. Thanks for watching

[@khimroy3958]

High voltage transmission towers also can get EM wave to light up a small LED 😊

[@technologyforyou5976]

Some people try to harvest power from HV transmission line, however these are not EM wave. Power harvested from HV line is called reactive power. It is in a sense stealing power from the grid.

[@yeroca]

@@technologyforyou5976 You are stealing RF energy from the transmitter :D Not much, but this is a zero-sum game.

[@technologyforyou5976]

@@yeroca Thanks for your comments. Harvesting RF radiated energy is not stealing. On the other hand reactive energy from HV line is stealing because electric supply company sees that some energy is leaked away by these process and they will be loosing money because of this. RF radiated energy is already gone, transmitter owner knows that this energy is gone. In some countries of europe (like UK) this kind of RF energy harvesting is discouraged not because of stealing but because of absorbing a part of the energy which could other way travel to a radio audience with better reception. By google searching you will find lots of other articles about it

[@azlanjumat2745]

Experimenting with harvesting free energy from radio transmissions is a promising approach. However, utilizing a solar power system is more efficient.

[@technologyforyou5976]

Thanks for watching and thanks also for your comments. Yes, I must agree that Solar energy harvesting is much more efficient. RF energy harvesting could be better only in remote or inaccessible region. During daytime solar energy can power devices and some energy can be stored in battery, however with time and lack of maintenance, batteries may not last long. Only in those cases EF energy would give us better result. Like telemetering, or remote sensor reading

[@markhodgson2348]

Multiple array and lyden jars "project moses "

[@vanhetgoor]

An interesting experiment would be if the antenna is not tuned, then all frequencies of all transmitters would be on the wire, would this not theoretically result in a higher voltage after the diode.

[@technologyforyou5976]

Actually if you remove the antenna tuner capacitor, the voltage after the diode is little less. This antenna tuner also serves as a impedance matching device so we get a little higher voltage. Back in old days people used to make their own radio receivers some people use it and some don't. Thanks for your comment and watching

[@pokrec]

Question: what do you need selective LC tank on the input, if you do not need to listen to the radio?

[@technologyforyou5976]

Tuned circuit is needed to maximize the power received by the antenna. Without the tuning circuit some power will be reflected by the antenna.

[@Pele19x89]

Hello. I have a small question. What about the impact of a thunderstorm or worse a lightning strike?

[@technologyforyou5976]

Back in old days, when there not that many high rise buildings and no cable TV, equipment (TVs and Radios) used to have lightning arrester just at the antenna end. This is nothing but a gas filled tube with two electrodes. When lightning strikes this tube shorts the electrical impulse to the ground. Now you will find lots of buildings and power lines are located way higher than your antenna height. So if you living in cities, you will get a little higher electrical pulse at the output. Most of the cases nothing will happen more than this. However, in remote location and in a kind of open area lightning can burn this kind of circuits. Now a days you won't find those lightning arrester, buy you can use Varistor instead. This is sufficient to protect this kind of electronics. Though a severe lightning strike can damage this varistor itself.

[@7gone]

Would be nice to know if that device when sucking energy from RF is also making a signal weaker? Also I am living near to Cell Tower Antennas like 50meters, is there any way to block those EMF ? And last question, is those RF is very bad for human body?

[@technologyforyou5976]

Thanks for watching and your comments. Yes, sucking some power will make some part of the signal-wave weaker. However a broadcast antenna radiates everywhere, so if a tiny part gets weaker, does not cause much problem. Harvesting radiated power is not illegal in most of the countries of the world. If you are living very close to a cell phone tower, you may be able to harvest power from that, but you need high frequency rated components, antenna will be smaller, but little difficult to tune for optimum power harvesting. Yes, it is possible to block those signal, using a very fine metal metal mesh you can make a cage like structure, and that should be connected to ground. This metal mesh-room is sufficient to block most of the signals. This RF energy, whether it is harmful or not is still a debate. There is no scientific proof that RF from cell phone tower , TV or Radio antenna can cause any harm. However some people did some statistical data analysis, they find that people who live close to a cell phone tower suffer from some illness. Just to let you know, these these RF waves are called non-ionizing radiation, and till now there is no scientific proof that these radiation can cause any harm to a living cell. Ultraviolet light, x-rays are also electromagnetic waves but the frequency is way higher than RF waves. These are ionizing radiation and cause harm to living organism, the proof can be seen right away.

[@7gone]

@@technologyforyou5976 Thanks for such detailed reply! Yeah I know about faraday cage , and ionizing radiation too, but I am wondering why telecommunication companies love to share a strange example of sun radiation and rf radiation, they telling that sun radiation a lot of times have stronger radiation, but I think it's a different thing and not comparable, because when you lay down on the sun, the heat is coming slowly from top of skin to the deeper body, and if you put your hand in to microwave oven it will heat you from inside, like food from microwave oven has more heat inside, than outside... So cell towers radiation is the same they go to he deeper body parts and resonating with water. So whats happening when is sleep time, sun is gone, but the cell towers works 24h. Let me know if I am wrong? Thanks again!

[@ATISzlotniskaTORPsan]

Scatman John is Alive !!

[@parul426]

Very nice video sir...could you please make a video on UWB rectenna

[@technologyforyou5976]

Thanks for watching. I'll try to make a video on rectenna in future

[@SecureSuppliesLimited]

nice for hydrogen making

[@technologyforyou5976]

If you are close to the transmitter, then you can harvest several watts to generate hydrogen by electrolysis of water. However further you go from the transmitter power goes down, in that case solar energy harvesting is a better choice.

[@Adrian_AdamViolonDiGerma-tm3nq]

What is the AC voltage of the original AM signal?

[@snakezdewiggle6084]

The larger the diameter of the antenna, the broader the band width of reception. Receiving distance is a function of polarity. But there are two cases to consider, sky waves (reflected from below the horizon), ground waves (low frequency, horizon to horizon). Now we risk a moral debate. Drawing energy from the power-grid, for free, legally. Or do we explore, energy from the ground.

[@MaximumEfficiency]

Nice, we know that those "death towers" can easily radiate >10W/m2 in the nearby surroundings.

[@TheFabie37]

Would be nice to see IoT devices being powered by radio waves or even recharged by them. Would save needing to constantly replace the batteries in them.

[@technologyforyou5976]

Unless radio stations are close enough, power is usually small. But you can make your own transmitter to power devices or charge devices. CB radio band (27 MHz) is still available, but I guess only 5W is allowed to transmit. Thanks for watching

[@jnawk83]

the need for many meters of wire rather defeats the point - just run a wire to a power source - at low load the I²R losses would be minimal

[@vylbird8014]

I looked into it. It works, but you need a lot of wire to get enough to run even a microcontroller that sleeps most of the time - think microamps, not milliamps. It's more practical to just use a tiny photovoltaic, like the ones used for garden lights.

[@ash.ab.5575]

even amateur school kids knows that much, what is not possible to know is how to multiply it

[@technologyforyou5976]

People should have some basic knowledge of electronics and electromagnetic waves to understand what I presented. unfortunately you don't have that.

[@MagraeMagraed]

And if you add a joule thief to absorb the lost energy and increase the voltage of the radio wave.

[@technologyforyou5976]

Yes, indeed you can increase the voltage using a Joule thief. Thanks for watching and your comment

[@h7opolo]

Cosmic microwaves are free, abundant, and ever present day and night, yet possibly attenuated by clouds.

[@technologyforyou5976]

thanks for watching. Cosmic background microwave is really very weak to harvest anything out of it.

[@deltab9768]

Cosmic microwaves are generally not coherent so I doubt they add together into a voltage.

[@danonino2003]

do you know eric dollar's work to power a 100w bulb with a crystal radio?

[@technologyforyou5976]

Please send me the link of Eric Dollar, thanks

[@krissstandke5076]

What if you had 10 wires in your yard? Would you get 10x the power? If I live just a few hundred yards from a cell tower and under a mile from several AM radio towers... how much energy could I potentailly harvest?

[@technologyforyou5976]

Thanks for watching. 10 closely located wires will not give you much more than a single wire for AM waves. Waves of energy hitting the firs wire, reduces the strength of the waves in that direction. So for AM waves you have to increase the length of the antenna. For cell phone signal, you should use multiple small antennas spaced nearly a wavelength apart. Other question is how much energy you can get, for cellphone signal, not much as these are transmitting low power signals. AM power is 50 kW (usual) so can get several watts if you live nearby. You can light your home and charge your devices. But not heating your home, that needs huge power.

[@fransjebik8554]

​Thank you so much! @@technologyforyou5976

[@Blameberg]

Didnt know Scatman went to electronics

[@technologyforyou5976]

I never heard of Scatman, however after google search I found resemblance of my face with him. I really laughed a lot after seeing that. Thanks for watching

[@miltonfilho2386]

Hi teacher, i live in Curitiba city, Brasil. I did not find BAT43W, but i found an equivalent,1N5818. My doubt Would be if the voltage Would stay less than with the BAT43W, because i Only obtain 110mV (milivolts) with this diode 1N5818. Thanks

[@technologyforyou5976]

Thanks for watching. I think your diode should be OK, there could be some other factors, like the antenna length is not long enough, your location could be much further than that I did the measurement, etc. If you could explain a little detail, I can get a better picture.

[@miltonfilho2386]

Hi teacher, i obtained a considerable Voltage increase to 0.8V (maximum). I also decided install a Phone, and discovered that this circuit Only tune one Station ! I turn the Variable Cap to right and left, but i Only Hear one Station ! Please, how to solve this defect ? The tuning Cap i use has 0 to 500Pf ! And the inductor i am using has 400 microhenrys. I mounted the circuit exactly equal the schema, but i don't know what is happening!

[@sajjadhaidar1231]

@@miltonfilho2386 Hello, The LC tuning circuit Q factor is important in tuning. If one signal is much stronger than other signals, usually that strong signal dominates. Of course a high Q tuning circuit will allow you to tune better. I think what you can try, make your own inductor with a thicker wire (AWG 18,or 14) on a ferrite rod. Nearly, to 200 to 300 turns may give you 600 to 1000 micro Henry.

[@Danieldrar-no2kl]

which antenna is best ,is that possible to use wifi ,tv antenna

[@technologyforyou5976]

Depends on the band of frequency you are interested in. Here I showed only MW harvesting, the wavelength is big, so we need long antenna. for WiFi or cell phone signal you need small antenna, as these use much higher frequency (small wavelength). But, the power of Wifi or cell phone signal are very low and the range is short.

[@QHQ76345]

Jewel thief that shit 😎

[@F76986jhg]

It's a really cool project. Would it be possible to power a 1.5v quartz clock? A hug from me to you, greetings from Brazil❤😊.

[@technologyforyou5976]

Thanks for watching. It is easy to power a LCD clock as it does not need much power. For a quartz mechanical clock, the motor needs little more power. So if you are located few kilometers away from a radio station, it will be possible. In my case my home is 25 km away from a station, so that power is not enough to drive a mechanical clock.

[@Privacityuser]

i just want to do an head phone power by local radio wi fi

[@mohinderkaur6671]

try BLE, wifi is power hungry

[@iok625]

hello sir, pls I need your help. Pls can you create a step by step video on creating your own RFEH system that can power several LEDs .Pls especially the components(all) for that project. Am also close to an AM radio station .Am kinda new to this field .Pls help me🙏🙏🙏

[@technologyforyou5976]

Hello, Thanks for watching. Once I prepare a project, usually I disassemble after sometime. It would be time consuming for me to make another video showing all the steps. But I can tell you something that may help you. Firs buy some components from any local electronic components store or Amazon. These are a ferrite rod (1cm dia or whatever you find), Two variable capacitors (100 to 500 pF), several ceramic capacitors (0.1uf to 5 uF), a small signal schottky diode, several same type and colour LEDS. After making the circuit, connect the antenna (should be more than 50 feet long to be effective). Now tuning the two variable capacitor you may find a suitable position to maximize the LED brightness. Connect all the LEDs in parallel. Do not mix different types of LEDs. Each color-LED has their own cut-in voltage, If you use multiple color_LEDs in parallel only one colour of lower cut-in voltage will glow. For instance if you wish to use Red LED, use multiple red-LEDs. If you need further assistance you can send me email. Thanks

[@carlomagnofernando2094]

What if you added joule thief to boost the voltage?.

[@technologyforyou5976]

Thanks for watching. Joule thief can only boost voltage, but power remains same. At the output, you will get higher voltage and lower current

[@carlomagnofernando2094]

@@technologyforyou5976 thank you for the expert advice. I really appreciate it.

[@mohinderkaur6671]

If you just wanted to harvest energy, why would you want to filter the waves and restrict yourself?

[@technologyforyou5976]

Filtering is done with only capacitors, so no energy is wasted. Filtering is needed to remove or reduce ripples. Thanks for your comments and watching the video

[@allanjuma675]

Maxwell chikumbtsu PROJECT just attach his name to avoid theft 'you have stolen it or what

[@technologyforyou5976]

I have never heard of his name, theft is out of question. Anybody can build any project, some may look similar. It is a very basic circuit. Similarity may seem obvious. Look carefully and compare carefully ball kinds of similar projects before putting this kind of question.