That’s a brilliant idea as there are so many board and table top games this could be used for. I could see everything from chess, checkers even Monopoly to thing like Warhammer and DnD. The limit is only the imagination. It could even be used with dioramas too.
Decades ago, doing some fisheries research, we used these small devices encased in resin so they could soak at depth in the sea. Just timers that ran until the magnet was pull off the reed switch when a fish hit the line. They were used until the battery died and replaced. This device seems useful to get a much longer use period by recharging the batteries. No doubt today they use "smart" timers that fail most of the time or something.
As usual - very thorough explanation with photos for reference and NOTHING was destroyed. You should fit in "nothing was harmed during the making of this video". In general, all electronics is getting so tiny that soon the only way to explain is going to be via highly enlarged photos.
@@nrasmussendk my preference would be mm with inch text on screen, but that add to an post production work load. and not every one wants to sit at a computer for hours.
I remember back in the 90s, the inductive charger on a Braun toothbrush was fascinating, these days it's everywhere, transferring power in a way that Nikola Tesla would be pleased to see... :D
Technically this is very different from Teslas wireless power transfer. This is just an oscillating magnetic field which works at short range, while Tesla theorized electromagnetic waves for longer distances. The problem is that high energy electromagnetic waves are not just incredibly inefficient for power transfer, but they also cook everything in their path.
Tesla would think wireless power transfer is as shit as I do. He was already powering lights across a room over 130 years ago and wanted to power street lighting, ships, and *planes* wirelessly. Of course he didn't understand how the nature of nearfield radiation or the inverse square law both make such dreams an impossibility, but he nonetheless would have been as unimpressed and bored with the millimeter alignment needing and useless after a mere cm distant nature of today's garbage wireless power transfer technology as I and many others are.
If you ever feel inclined to do a whiteboard showing the AC and DC voltages that would be really interesting. Thanks for another great class. Also if you were to get an ascilloscope and show us what's happening that way it would be very interesting.
How much power does the transmitter consume when it isn't connected to the receiver? I always wonder if these are smart enough to go into standby, or if some external MC has to detect that scenario somehow...
@@bigclivedotcom So I guess the circuit was designed to comply with laws against "vampire loads" wasting too much power at standby. 0.12W for the transmitter, 0.2W for the mains adapter and 0.15W for a standby receiver within a 0.5W legal limit.
There’s a mania for wireless charging of ABSOLUTELY ANYTHING that I can’t understand. I can’t use my phone comfortably when it’s sitting on a wireless pad: maybe that’s just my poor eyesight. The big obsession is with wireless charging of electric cars. I can’t see how that can be efficient.
@@gorak9000 I agree it's not the most efficient way of doing things, but it would be convenient in some situations. Imagine, for example, your place of work, a shopping centre, etc. with coils buried in some of the parking spots. Just park in one of these spaces and your car automatically charges while you're away without any mucking about with cables.
Be nice to see some tests, like quiescent supply current, frequency variation and how the power transfer is related to frequency and resonance. Does it behave like an antenna or a transformer? Input to output graphs. Power transfer vs distance etc... So many more questions! This vid is just a teaser! 👍🏻🇬🇧😀
Could it be used as kind of a power source and a key for a hidden lock? Battery powered transmitter... Slide it over the right spot and it would Charge up some capacitors to a controller that would then discharge and power a small electro magnet plunger that would retract and a small spring would pop the little hidden compartment door open.. would be kinda neat since you wouldnt have to have the "key" near the hidden compartment..
@@DrakeOola Except the receiver is in the hidden lock (keycard) and the power source is in the key. Don't forget to add a data protocol to do a secure handshake so no other key opens the lock.
Going way back to the 1950s and in operation for decades, there was a remote RF-powered listening device hidden in some American embassy with a transmitter. They don't like to talk about it even today. No batteries of course. I think it was in a picture frame. A van parked out in the street beamed microwave at the part of the building to activate the microphone and the Russians could listen in. These things popped up all over the world and for decades people working in embassies were suffering with acute headaches being in the wireless beam
@@jagmarc , you might be conflating several different kinds of electronic surveillance. The American embassy in Russia was built by Russian contractors and was rumored to be "bug"-infested. I don't know if wireless power was ever used to activate or reactivate hidden transmitters that didn't have an internal battery or power source, but using sufficient microwave beampower to cause headaches shouldn't be necessary just to make a listening device function, and such power would likely overload and obscure the return signal being transmitted out to a spy receiver (although perhaps a digitized return signal would work). Of course, ever since lasers were invented, spies have had the ability to pick up vibrations of a window pane caused by people speaking inside the building, and reproduce that up as sound. BTW, Leon Theremin, the Russian who emigrated to the United States and invented the theremin, was reputed to have also built spy devices and transmitters for Russia.
So what we have here is a split 1:1 transformer, without core. Cores are put in transformers to make a better magnetic coupling, so there's less energy transfer loss. It's a fun idea, but it's not optimized for what it's supposed to do: Energy transfer. Doing a quick back of the envelope calculation, this system puts the same losses back into place that we had with incandescent lightbulbs. Just now we get the light from an LED, a light system we've adopted to save energy. Welp, there go your energy savings. Just so it's "wireless". Makes me wonder what RF screams it puts out.
Well it's not completely useless, its fairly thin so it could easily be mounted in a thin case or something as a cheap inductive switch/sensor perhaps. Also, charging ports tend to be points of failure and they also pose somewhat of a threat in terms of fires due to possible shorts (A guy who educates on fire safety told me that phone charger leads cause more fires than you think). The constant plugging and unplugging always wears the socket/plug out in the end. It's for precisely this reason that I now mostly charge my own phone on a wireless charging pad, because I got sick of charging cables or improper connections in the socket
i designed my 3d printed robot with a recess in the bottom so I can fit the 1A version of this into my robot so I can just drive it onto the charging station and it can lower itself onto it. I planned on having a magnet too to help keep it center but when I tested it it showed a huge decrease in efficiency so that got scrapped maybe smaller magnets on the outside of the coil would work better
Nice little thing I guess some people will blow up a battery or 3 with no protection. But protection feels just wrong in some situations. great video 2x👍
On the receiver it appears the feedback for the linear regulator is 2.5 Volts e.g. 4.2 * 1meg/(680k+1meg) = 2.5 Volts. The IC will do its best to manipulate the output to see 2.5 on the sense pin
Others already requested the frequency. I am curious to know if the parallel LC is tuned to have resonance at that frequency, or if the capacitor, is just there to decouple. If I remember correctly from my electronics days, if you make a parallel LC circuit and pulses it at its resonance frequency, it will create relative high currents in the coil.
LC series tank creates high current in resonance, LC parallel tank creates zero current in resonance. A capacitor has reactive impedance of -1/(2*pi*f*c) imaginary Ohms, and an inductor has 2*pi*f*c imaginary Ohms. When |ZL|=|ZC|, we call it resonance. When they are connected in series during resonance, as |ZL|=|ZC| and they have opposite signs, ZL+ZC=0, thus the series impedance is very low, only contributed by the resistive bits of the L and C, which are usually very small. When they are connected in parallel during resonance, since Zp=(Z1*Z2)/(Z1+Z2), ZL+ZC=0, we have a denominator of zero, thus the impedance is infinite assuming no resistive bits' presence.
Ya know what I'd like to see made wireless? Multimeters! Imagine a set of battery-powered probes that communicated wirelessly to the display of the multimeter. Wouldn't that be great, to not have wires that twist and tangle and drag across the bench, knocking things off the table? I guess the limiting factor would be how small you could make the probes and how long their batteries (rechargeable, of course) would last.
@@bskull3232 You are referring to the use of LC coupling as a filter, Then it is true that the current coming out of the filter will be low on resonance frq with a parallel coupling. However if you look inside the L and C High amount of current is flowing between them. You are correct that the impedance is of opposite signs, or in other words the current is 180 deg out of phase. So when current is going "downwards" in the C, it goes "upwards" in the L cancelling each other out so the output of the circuit is zero (ideal L and C) thus the bandstop effect. (Upwards/downward is a illustrative reference to the diagram Clive had drawn.) In a real circuit this high current in mainly limited by the R in the real life non-ideal coil. This is also why you need the transistor/FET below to push the current like when you push a swing.
Back in the mid/late 80s we had so much fun with inductive/wireless power transfer. Another great use for it was quick detach of radio transmitting equipment from a fixed aerial (stateside: "antenna" ).
Looks like the receiver chip S pin is looking for a 2.5v reference. So for true USB spec voltage, if you put a 1.8M Ω resistor in parallel with the existing 1M Ω resistor you’d get about ~5.1v out, or around ~5.3v out by using a 1.5M Ω
Now these, I can also see uses for model railways... Fit a reception coil on a loco, hooked up to trigger a horn/whistle, and place the transmission coil up where the whistle signs are on your layout.
If you just want signalling to trigger a horn, put a magnet under the tracks, and a reed switch or hall sensor on the engine. No need for all this complication just to trigger a switch
Hi Clive! I wonder if anything changes in the max output power if one of the two circuit is flipped with respect to your tests. I love your videos! Greetings from Italy!
The transmitter has an XKT-R1 mosfet to send a "signal" to the coil. The receiver has an XKT-R2, which I'm guessing somehow "decodes" the signal from the coil. They look like a pair of chips meant to go with the XKT-001 specifically for this application.
Isn't it used in those battery powered candles in restaurants? When they close they collect all of them on the charger. It is powered by a single lir2032 or so. Would explain the 4.2V.
I could see these being great trickle chargers on something that sits a lot. Night lamp you only take to go to the toilet, toothbrush, restaurant beepers etc
Using the diode on the output, I suspect more that it is a switching regulator. You can measure the output from the chip, it's waveform will expose the secrets.
What happens if you put some steel on the coil ? The complexity of the higher power phone chargers is largely to avoid it putting significant power into an accidental load
The better wireless phone chargers support two-way communication so the that the driving circuit can adapt to the different load requirements as the phone charges. Of course, there is also protection, but some of that is managed in the phone.
If the output is 4.2v beyond the Schottky diode, the output from the regulator is ~4.5v and the voltage at the sense input should be ~2.7v? Correct? It looks like a change to the voltage divider could give you a pretty wide range of voltage output; 2.4v-6v (again with the diode drop).
Useful for powering up War-Hammer 40K vehicles to charge batteries that power LEDs for display lights while gaming. Some uses for Model Railway vehicles too and flashing LED rear warning lights on wagons, coaches, and Brake vans.
"Wireless Charger" is a far better name for those things. This just reminded me of something from many years ago, someone was talking about some 'chee' charger except they didn't spell it that way (and a bit wrong if it was supposed to be English), and I thought they were trying to tell a very complicated not so funny joke about a particular type of fart. I think my reply was something along the lines of, "I don't want burnt transformer smell filling my house, I just want a cellphone charger that works", lol.
Would an application be lapel pins with led lights built in? Most if I recall correctly have the electronic components on the outside portion of the pin which makes them somewhat bulky. If this could move the electronics to the inside portion of the pin it would make the pin appear cleaner on the shirt/lapel.
Clive, with how much money you spend on ink, I have to ask. Are you refilling the cartridges yourself or letting them jew you crazy price for every replacement? TR4550 does not have DRM and can be refilled very easily. Put ink in, blow into it to get air bubbles out, put piece of tape on top leaving only the tiny channel to take air, and it just wooooooorks.
@@bigclivedotcom even better. I installed one of those system on a HP, but it seems the HP can self destruct. It squirted ink on its own little ribbons, and what I noticed, is every time it "parks", it wastes a lot of ink. It was new, changed cartridges twice, and the pads inside were SOAKED, before I even installed the continuous ink system. Long story short, HP is VERY bad.
I guess they could be used to charge some compleately sealed devices that can't have any external connector or something like that... maybe a lora device?
The little coil reminds me of those solar dancing figures, like the dancing flower. Maybe you make a solar base that you can swap different dancing figures and lights at will.
Clive, do they make wireless transfer units that I could attach to the bottom of my kitchen table and sit a artificial flower pot with LEDs on top and have it light up with out a cord? The spacing would have to be 3/4 to 1 inch. The powered unit would be underneath attached to the bottom of the table and plug into the wall with a walwort. My wife could have various arrangements and Halloween and Christmas displays as well. I haven't seen any yet, have you?
You could possibly do that with a standard Qi charger plate and one of the 5V output receivers sold on eBay. The gap is significant though, and may be a factor.
I built another device into the back of my meter to recharge the 7v2 liion and power it for long recordings, but the circuit is bulky compared to that thing and tends to run quite warm.
This is kinda untuned resonance WPT system. Since no tuning is available, it is natural that the system will have high losses and pretty variable voltage gain (Therefore too close the LDO will blow up). Thought it is a LLC like in Qi wireless charging standards.
1:01 I'm not an expert in Chinese, but even the original text "大于2 mm用放近会坏!!" seems quite sloppy for me. "大于2 mm用" could mean "use [them] more than 2 mm [apart]" and "放近会坏" "putting [them] close[r] will cause harm".
I would guess, the efficiency is very bad. From the video: Sender: 25mA standby current, 100mA at max load. (Loss 25%) Receiver: 6,35V -> 4.2V linear regulator (Loss 34%) We know 0,75 * 0,66 = 0,5. Multiply with factor 0,5 for all we don't know, my bet would be 25% efficiency at 2mm distance. At greater distances you could switch to LED and solarpanel :-)
My first idea for im-practicable use, was LEDs in a plastic bubble with elle gubbins and a wee batt. floating in a translucent water fountain powered by a wind generator 'n' solar ... the rim of the base or in the rising tube as point of recharge ? Totally useless but oh so pretty..
I you go back up in the comments, someone else says likely the biggest cost is the printing, and Clive replied that he got the Epson Ecotank printer, what model, don't know, he didn't say.
Could it be that the output is 5V and that diode on the receiver is a regular silicon diode instead of a Schottky? That would explain the '5V output' specification
Very interesting I wonder if it could be implemented to charge every mobile phone so that we don't have to unplug the power cable all the time. The power socket has been the failure point in my last few phones
Hello, Dear friend, we have a problem that we. need to transfer some data through the double coil, one coil with sensor sending sensing data, another coil with wireless power supply, now we are using the xkt 510 to generate 100khz AC, but we don't know how to sensing the sensing signal. I f you have some great idea, please let me know, we will appreciate it very much. Thanks
I've got a smartwatch that I want to try and fit one of these into. It currently uses a proprietary pin charging system and the internal battery says its 3.7v. I was just wondering if you think this would still work
My BV9900-pro does not like wireless chargers. I bought 2 chargers to try out. about $30 each. I gave up on them due to them tripping the thermal sensor in the phone, melting the plastic case or both.
My previous Samsung phone came with a round charging pad and the rectangular phone had to be placed somewhat off center and very specifically on the charger in a certain way otherwise it wouldn't work. No thanks!
...we can utilize this tech to remote control with rechargeable batteries to turn relays on appliances like tv..so we could eliminate stanby powers needed to turn on tv for example..this makes appliances more power efficient and lightnings surge protected.. isolated from the grid until Its actually used..remote powerup within 10 meter range..
If its output is 4.2V then it is no use for charging a phone wirelessly? Can it be made to charge a phone? Or have I missed something? It would be good it it would put some charge into a phone during the night, just drop the phone and it would charge when not being used, slowly I must admit, but my phone sits about a lot doing nothing when it could be hacked to charge during this time!
I recently had to replace my phone and got the Samsung S21FE for one main reason, but secondary reason is for NFC (near field communication) for touchless pay). Looked into it in 2018 but my G6 from Motorola didn't have that, let alone wireless charging and at the time, it was looking like I could not use my debit card, with it as the software was not compatible with my card. Now, my credit union can accept Samsung, Google and at least 2 other tap to pay software so I'm setting that up. At that point, I didn't realize that you likely could change out the tap to pay software out even then. The wireless charging is to reduce the strain/load of the USB for nearly daily charging of the phone (4500mh) battery and Snapdragon 888 processor means roughly a day of use between charges. At 5000Mh battery on the slower processor of my g6 meant a day and a half of use between charges when new but the failures was the USB port becoming loose and charging capabilities ceased to work, on both phones, one I bought new, the other a reman unit to replace the first phone and that second phone was acquired in January and the port was not as tight when I plugged in the USB cable to start with and by March, had failed to charge, so the Samsung was procured. It is considered a mid tier phone, and was the ONLY one to have wireless charging, never mind it is only 10W, so not the fastest, but will charge my phone from roughly 5% in about 2 hours in any event.
No, it just has a "tail" that extends past the capacitor pad a bit. I'm guessing it's either for antenna tuning, or they copy-n-pasted the antenna and didn't clean up the extra.
Question: I want to installl a 10k type B linear potentiometer (I don't need audio logarithmic) inline to a mono out jack for a metal detector for headphones (no volume control). I'm going to put signal in to lug #1, out to jack from wiper lug #2. If I leave the third lug open (not grounded) will it damage the circuit?
@@bigclivedotcom That "You should" does not sound too confident. 🤔🤣 I'm just going to solder #3 to pot case then to pcb ground. What can it hurt? I I saw a diagram for 5K for headphones, so I figured 10k to be safe. Also linear taper because I'm just setting it at one point (not blowing my eardrums).
I recently tried messing with one of those (the 5v buck version though, needed a longer range), and appears a series-connected loading LC performs much better than the parallel one they use. Why the parallel circuit? Just for getting rid of the extra diode?
Embedding them into a gaming table and game pieces sounds like a lot of fun!
This needs drawings. I would love to build a game
That’s a brilliant idea as there are so many board and table top games this could be used for. I could see everything from chess, checkers even Monopoly to thing like Warhammer and DnD. The limit is only the imagination. It could even be used with dioramas too.
And will be discovered by anyone with a gauss meter. Heck, even most phones have one. That's how the compass works without GPS.
Dont see how people discovering them is an issue....
That's what casinos do with their chips, though it's rfid
the beauty of the channel is how he magnifies everything so you can see it so well. no straining of the eyes or guessing
Decades ago, doing some fisheries research, we used these small devices encased in resin so they could soak at depth in the sea. Just timers that ran until the magnet was pull off the reed switch when a fish hit the line. They were used until the battery died and replaced. This device seems useful to get a much longer use period by recharging the batteries. No doubt today they use "smart" timers that fail most of the time or something.
As usual - very thorough explanation with photos for reference and NOTHING was destroyed. You should fit in "nothing was harmed during the making of this video". In general, all electronics is getting so tiny that soon the only way to explain is going to be via highly enlarged photos.
Thank you, Clive. I've noticed that you measure things in mm, but then you report in BOTH mm and inches.
I like to try and be inclusive with different standards.
It's quite annoying. SI units only, please.
@@nrasmussendk my preference would be mm with inch text on screen, but that add to an post production work load. and not every one wants to sit at a computer for hours.
Hadn't given it much thought before, it's kinda nice to have wireless charging explained in such easy-to-understand terms. Thanks and good work.
Clive's biggest expense is definitely printer ink.
Not Sharpies or lined notebooks?
LOL 👍
Epson ecotank with bulk ink.
And marinades for all those babies he eats.....we've all heard the stories about the Isle of Mann 👶🍴🥩🇮🇲
@@zh84 he refills the pens with printer ink -> ruclips.net/video/MGPhwzJDmSg/видео.html
So many possibilities! Clive has been getting some really awesome stuff lately! 😃
Clive, I appreciate that you took the effort to print those photos out!
I remember back in the 90s, the inductive charger on a Braun toothbrush was fascinating, these days it's everywhere, transferring power in a way that Nikola Tesla would be pleased to see... :D
Technically this is very different from Teslas wireless power transfer. This is just an oscillating magnetic field which works at short range, while Tesla theorized electromagnetic waves for longer distances. The problem is that high energy electromagnetic waves are not just incredibly inefficient for power transfer, but they also cook everything in their path.
@@drkastenbrot its an alternator laid flat
Tesla would think wireless power transfer is as shit as I do. He was already powering lights across a room over 130 years ago and wanted to power street lighting, ships, and *planes* wirelessly. Of course he didn't understand how the nature of nearfield radiation or the inverse square law both make such dreams an impossibility, but he nonetheless would have been as unimpressed and bored with the millimeter alignment needing and useless after a mere cm distant nature of today's garbage wireless power transfer technology as I and many others are.
If you ever feel inclined to do a whiteboard showing the AC and DC voltages that would be really interesting. Thanks for another great class. Also if you were to get an ascilloscope and show us what's happening that way it would be very interesting.
Yes! That and efficiency curves swept across power draw. Maybe tweak the frequency and see how efficiency changes, too.
How much power does the transmitter consume when it isn't connected to the receiver? I always wonder if these are smart enough to go into standby, or if some external MC has to detect that scenario somehow...
24mA at 5V. About 0.12W
@@bigclivedotcom So I guess the circuit was designed to comply with laws against "vampire loads" wasting too much power at standby. 0.12W for the transmitter, 0.2W for the mains adapter and 0.15W for a standby receiver within a 0.5W legal limit.
There’s a mania for wireless charging of ABSOLUTELY ANYTHING that I can’t understand. I can’t use my phone comfortably when it’s sitting on a wireless pad: maybe that’s just my poor eyesight. The big obsession is with wireless charging of electric cars. I can’t see how that can be efficient.
@@markiangooley Who in their right mind is talking about wirelessly charging electric cars? That's just downright dumb
@@gorak9000 I agree it's not the most efficient way of doing things, but it would be convenient in some situations. Imagine, for example, your place of work, a shopping centre, etc. with coils buried in some of the parking spots. Just park in one of these spaces and your car automatically charges while you're away without any mucking about with cables.
Could be useful for Gamepads, I might try it with my dualshock 4. Useful size and voltage for this.
I love the fact that you always print a high quality photograph and cut it to the circuit board shape. Totul quality so it is pal!
Maybe use it for powering decorative LEDs through window glass? Thanks for the video Clive.
It’s a great Saturday morning coffee when bigclive uploads 🍻👍🏻🇨🇦
Perhaps I will use it to create a hidden power supply for my super computer. Hmm, perhaps. Good work Clive.🔥👍🏻🥃
sounds like a good idea. 2x👍
Just found your channel already set the stuff is so nice to watch love it keep it up the good work
When I see Clive's drawing of a LED symbol, I always think about a farting LED. Better name for it would be a Fart-Emitting-Diode, FED! 😅
I set an LED on fire once, and indeed, I FLED from the smell ! 😁
Be nice to see some tests, like quiescent supply current, frequency variation and how the power transfer is related to frequency and resonance. Does it behave like an antenna or a transformer? Input to output graphs. Power transfer vs distance etc... So many more questions!
This vid is just a teaser! 👍🏻🇬🇧😀
I quite understand what you have explained. I see there are spiral coil. Thank you for sharing
Could it be used as kind of a power source and a key for a hidden lock? Battery powered transmitter... Slide it over the right spot and it would Charge up some capacitors to a controller that would then discharge and power a small electro magnet plunger that would retract and a small spring would pop the little hidden compartment door open.. would be kinda neat since you wouldnt have to have the "key" near the hidden compartment..
You're just describing nfc keycards now...
@@DrakeOola Except the receiver is in the hidden lock (keycard) and the power source is in the key. Don't forget to add a data protocol to do a secure handshake so no other key opens the lock.
Going way back to the 1950s and in operation for decades, there was a remote RF-powered listening device hidden in some American embassy with a transmitter. They don't like to talk about it even today. No batteries of course. I think it was in a picture frame. A van parked out in the street beamed microwave at the part of the building to activate the microphone and the Russians could listen in. These things popped up all over the world and for decades people working in embassies were suffering with acute headaches being in the wireless beam
@@jagmarc , you might be conflating several different kinds of electronic surveillance. The American embassy in Russia was built by Russian contractors and was rumored to be "bug"-infested. I don't know if wireless power was ever used to activate or reactivate hidden transmitters that didn't have an internal battery or power source, but using sufficient microwave beampower to cause headaches shouldn't be necessary just to make a listening device function, and such power would likely overload and obscure the return signal being transmitted out to a spy receiver (although perhaps a digitized return signal would work). Of course, ever since lasers were invented, spies have had the ability to pick up vibrations of a window pane caused by people speaking inside the building, and reproduce that up as sound. BTW, Leon Theremin, the Russian who emigrated to the United States and invented the theremin, was reputed to have also built spy devices and transmitters for Russia.
If the transmitter has a current sense for when the matching circuit is near, you could maybe use it hidden inside a door to make a hidden interlock
So what we have here is a split 1:1 transformer, without core. Cores are put in transformers to make a better magnetic coupling, so there's less energy transfer loss. It's a fun idea, but it's not optimized for what it's supposed to do: Energy transfer. Doing a quick back of the envelope calculation, this system puts the same losses back into place that we had with incandescent lightbulbs. Just now we get the light from an LED, a light system we've adopted to save energy. Welp, there go your energy savings. Just so it's "wireless". Makes me wonder what RF screams it puts out.
Well it's not completely useless, its fairly thin so it could easily be mounted in a thin case or something as a cheap inductive switch/sensor perhaps. Also, charging ports tend to be points of failure and they also pose somewhat of a threat in terms of fires due to possible shorts (A guy who educates on fire safety told me that phone charger leads cause more fires than you think). The constant plugging and unplugging always wears the socket/plug out in the end. It's for precisely this reason that I now mostly charge my own phone on a wireless charging pad, because I got sick of charging cables or improper connections in the socket
i designed my 3d printed robot with a recess in the bottom so I can fit the 1A version of this into my robot so I can just drive it onto the charging station and it can lower itself onto it.
I planned on having a magnet too to help keep it center but when I tested it it showed a huge decrease in efficiency so that got scrapped maybe smaller magnets on the outside of the coil would work better
That's how apple did it with the newer set of phones, the ring of magnets around the coil.
I have been awaiting this for so long. Excitement overload!!!
Nice little thing I guess some people will blow up a battery or 3 with no protection.
But protection feels just wrong in some situations. great video 2x👍
That's what she said.
@@Dont_Tread_On_Me LOL
@@Dont_Tread_On_Me that's what _HE_ said
On the receiver it appears the feedback for the linear regulator is 2.5 Volts e.g. 4.2 * 1meg/(680k+1meg) = 2.5 Volts. The IC will do its best to manipulate the output to see 2.5 on the sense pin
Others already requested the frequency.
I am curious to know if the parallel LC is tuned to have resonance at that frequency, or if the capacitor, is just there to decouple.
If I remember correctly from my electronics days, if you make a parallel LC circuit and pulses it at its resonance frequency, it will create relative high currents in the coil.
I think the capacitor is for resonance.
LC series tank creates high current in resonance, LC parallel tank creates zero current in resonance. A capacitor has reactive impedance of -1/(2*pi*f*c) imaginary Ohms, and an inductor has 2*pi*f*c imaginary Ohms. When |ZL|=|ZC|, we call it resonance. When they are connected in series during resonance, as |ZL|=|ZC| and they have opposite signs, ZL+ZC=0, thus the series impedance is very low, only contributed by the resistive bits of the L and C, which are usually very small. When they are connected in parallel during resonance, since Zp=(Z1*Z2)/(Z1+Z2), ZL+ZC=0, we have a denominator of zero, thus the impedance is infinite assuming no resistive bits' presence.
Ya know what I'd like to see made wireless? Multimeters! Imagine a set of battery-powered probes that communicated wirelessly to the display of the multimeter. Wouldn't that be great, to not have wires that twist and tangle and drag across the bench, knocking things off the table? I guess the limiting factor would be how small you could make the probes and how long their batteries (rechargeable, of course) would last.
@@bskull3232 You are referring to the use of LC coupling as a filter, Then it is true that the current coming out of the filter will be low on resonance frq with a parallel coupling.
However if you look inside the L and C High amount of current is flowing between them.
You are correct that the impedance is of opposite signs, or in other words the current is 180 deg out of phase. So when current is going "downwards" in the C, it goes "upwards" in the L cancelling each other out so the output of the circuit is zero (ideal L and C) thus the bandstop effect.
(Upwards/downward is a illustrative reference to the diagram Clive had drawn.)
In a real circuit this high current in mainly limited by the R in the real life non-ideal coil.
This is also why you need the transistor/FET below to push the current like when you push a swing.
@@goodun2974 Well unless you invent a good way of wireless voltage potential transfer you would still need a wire between the two probes.
soon i will become a professional electrician because of your videos (i learn alot from it)
_Alot_ is a town in India. _A lot_ is more than one of something.
@@coloradostrong8285 He said he was going to be an electrician, not a typist :) But interesting to know about the town.
Back in the mid/late 80s we had so much fun with inductive/wireless power transfer. Another great use for it was quick detach of radio transmitting equipment from a fixed aerial (stateside: "antenna" ).
I'd like to play with some of these to see which of my little edc electronics could be retrofitted with wireless charging.
Looks like the receiver chip S pin is looking for a 2.5v reference. So for true USB spec voltage, if you put a 1.8M Ω resistor in parallel with the existing 1M Ω resistor you’d get about ~5.1v out, or around ~5.3v out by using a 1.5M Ω
Now these, I can also see uses for model railways... Fit a reception coil on a loco, hooked up to trigger a horn/whistle, and place the transmission coil up where the whistle signs are on your layout.
Just ordered two to see if they will charge the batteries in radio controlled locomotives.
If you just want signalling to trigger a horn, put a magnet under the tracks, and a reed switch or hall sensor on the engine. No need for all this complication just to trigger a switch
Hi Clive!
I wonder if anything changes in the max output power if one of the two circuit is flipped with respect to your tests.
I love your videos!
Greetings from Italy!
The transmitter has an XKT-R1 mosfet to send a "signal" to the coil. The receiver has an XKT-R2, which I'm guessing somehow "decodes" the signal from the coil. They look like a pair of chips meant to go with the XKT-001 specifically for this application.
Isn't it used in those battery powered candles in restaurants? When they close they collect all of them on the charger. It is powered by a single lir2032 or so. Would explain the 4.2V.
This'd be great for putting little secret compartments in furniture and opening them with a special 'key' device you could disguise.
What was the frequency of the coils?
Does anyone have a measurement of the frequency it runs at?
Thanks, Clive.
It would be nice to dig out the oscilloscope.
Cool, two wireless charging videos by my favorite RUclips channels, the other is: Sabine Hossenfelder.
With BigPower comes BigWirelessResponsability ❤️❤️❤️
What's the efficiency of power used in transmitter -> power collected by receiver ?
on QI chargers its about 50%...
so 5V 2A in gets you 5V 1A into the phone electronics.
I'd like to see someone made a snow globe with the wireless LEDs as the "snow".
Nice new video from Clive my friend! And it's about power and battery stuff.
I could see these being great trickle chargers on something that sits a lot. Night lamp you only take to go to the toilet, toothbrush, restaurant beepers etc
Using the diode on the output, I suspect more that it is a switching regulator. You can measure the output from the chip, it's waveform will expose the secrets.
As for the double coil design on the board, doesn't two inductors wound in opposite directions cancel each other out?
They're effectively wound in the same direction. One image is mirrored.
What happens if you put some steel on the coil ? The complexity of the higher power phone chargers is largely to avoid it putting significant power into an accidental load
Good question. I guess the transmitter will just heat up and die.🤔
The better wireless phone chargers support two-way communication so the that the driving circuit can adapt to the different load requirements as the phone charges. Of course, there is also protection, but some of that is managed in the phone.
I would like to see waveforms of the circuit operation.
Cheers Clive. Another interesting video of unusual electonics.
This is probably what charges my moms battery powered tea pot candles. And no she doesnt use them for heating the pot, they are for decoration xD
If the output is 4.2v beyond the Schottky diode, the output from the regulator is ~4.5v and the voltage at the sense input should be ~2.7v? Correct? It looks like a change to the voltage divider could give you a pretty wide range of voltage output; 2.4v-6v (again with the diode drop).
Useful for powering up War-Hammer 40K vehicles to charge batteries that power LEDs for display lights while gaming. Some uses for Model Railway vehicles too and flashing LED rear warning lights on wagons, coaches, and Brake vans.
Mine are already on the way :)
3d print chess set and use receiver to power LED inside pieces and put transmitters in squares maybe good use??
"Wireless Charger" is a far better name for those things. This just reminded me of something from many years ago, someone was talking about some 'chee' charger except they didn't spell it that way (and a bit wrong if it was supposed to be English), and I thought they were trying to tell a very complicated not so funny joke about a particular type of fart. I think my reply was something along the lines of, "I don't want burnt transformer smell filling my house, I just want a cellphone charger that works", lol.
I just love Clive's CAD.....it's awesome...😃😃...!!! Exactly like the one I use.....at least I'm not alone...!!!!
Would an application be lapel pins with led lights built in? Most if I recall correctly have the electronic components on the outside portion of the pin which makes them somewhat bulky. If this could move the electronics to the inside portion of the pin it would make the pin appear cleaner on the shirt/lapel.
It could work, but a much tider approach would be adding a flat lithium button cell.
Clive, with how much money you spend on ink, I have to ask. Are you refilling the cartridges yourself or letting them jew you crazy price for every replacement? TR4550 does not have DRM and can be refilled very easily. Put ink in, blow into it to get air bubbles out, put piece of tape on top leaving only the tiny channel to take air, and it just wooooooorks.
Epson ecotank for bulk ink use.
@@bigclivedotcom even better. I installed one of those system on a HP, but it seems the HP can self destruct. It squirted ink on its own little ribbons, and what I noticed, is every time it "parks", it wastes a lot of ink. It was new, changed cartridges twice, and the pads inside were SOAKED, before I even installed the continuous ink system. Long story short, HP is VERY bad.
@@dimitar4y Yeah. I had no joy refilling my old HP printer. It had a very odd ink-bag system in its cartridges.
I guess they could be used to charge some compleately sealed devices that can't have any external connector or something like that... maybe a lora device?
The little coil reminds me of those solar dancing figures, like the dancing flower. Maybe you make a solar base that you can swap different dancing figures and lights at will.
Clive, do they make wireless transfer units that I could attach to the bottom of my kitchen table and sit a artificial flower pot with LEDs on top and have it light up with out a cord? The spacing would have to be 3/4 to 1 inch. The powered unit would be underneath attached to the bottom of the table and plug into the wall with a walwort. My wife could have various arrangements and Halloween and Christmas displays as well. I haven't seen any yet, have you?
You could possibly do that with a standard Qi charger plate and one of the 5V output receivers sold on eBay. The gap is significant though, and may be a factor.
perfect comment and brilliant explaining for everybody
Could that curious text mean: "if short circuited, keep at least 2 mm distance"?
A very good Saturday morning to you sir from Wellington Somerset
Wonder how well it works through a couple mm of glass one might find in a typical fish tank? Could make for some interesting lighting effects...
Wireless floating leds everywhere brought to you by bigclive
Those chips and MOSFET have names that sound like something out of Thunderbirds.
Hey Clive, how about looking into these Fly By Wire Gas Pedal fixes, which take out lag in the Gas Pedal response, Scam or Truth?
I built another device into the back of my meter to recharge the 7v2 liion and power it for long recordings, but the circuit is bulky compared to that thing and tends to run quite warm.
This is kinda untuned resonance WPT system. Since no tuning is available, it is natural that the system will have high losses and pretty variable voltage gain (Therefore too close the LDO will blow up). Thought it is a LLC like in Qi wireless charging standards.
1:01 I'm not an expert in Chinese, but even the original text "大于2 mm用放近会坏!!" seems quite sloppy for me. "大于2 mm用" could mean "use [them] more than 2 mm [apart]" and "放近会坏" "putting [them] close[r] will cause harm".
In this video, I'm missing an efficiency measurement and a check on what happens when the transmitter coil meets an iron object.
I would guess, the efficiency is very bad.
From the video:
Sender: 25mA standby current, 100mA at max load. (Loss 25%)
Receiver: 6,35V -> 4.2V linear regulator (Loss 34%)
We know 0,75 * 0,66 = 0,5.
Multiply with factor 0,5 for all we don't know, my bet would be 25% efficiency at 2mm distance.
At greater distances you could switch to LED and solarpanel :-)
Waterproof gadgets need a larger gap from the charger to dry out than what the inductor systems have supported.
My first idea for im-practicable use, was LEDs in a plastic bubble with elle gubbins and a wee batt. floating in a translucent water fountain powered by a wind generator 'n' solar ... the rim of the base or in the rising tube as point of recharge ? Totally useless but oh so pretty..
Can I ask which printer you are using? Great stuff by the way! Thanks
I you go back up in the comments, someone else says likely the biggest cost is the printing, and Clive replied that he got the Epson Ecotank printer, what model, don't know, he didn't say.
i have the epson et-2550 with tanks. it is a great printer and no cartridge hassles.
You could use the photos to etch the FR4 pcb
Could it be that the output is 5V and that diode on the receiver is a regular silicon diode instead of a Schottky? That would explain the '5V output' specification
I tested the voltage and diodes.
Very interesting I wonder if it could be implemented to charge every mobile phone so that we don't have to unplug the power cable all the time. The power socket has been the failure point in my last few phones
Hence the Qi charging standard with similar receivers built in to many current phone models, but with a larger coil diameter.
@@johndododoe1411 yes but I mean something to attach to any phone so you don't need to plug in cable, say built jn to a case
You can get QI chargers that stick to the phone and have a thin cable that plugs into the charge port.
looks like it could be modified to output less than 4.2v, to prolong the life of the batteries, or just use a shottky/3.8v li-po cell
Put a single red LED on that board on the bench. Put the coil on top. Hit it with FLIR.
Does the receiver work with standard smartphone reverse power charging ? can I grab few mW from a smartphone wirlessly ?
These ones aren't optimised for that.
Hello, Dear friend, we have a problem that we. need to transfer some data through the double coil, one coil with sensor sending sensing data, another coil with wireless power supply, now we are using the xkt 510 to generate 100khz AC, but we don't know how to sensing the sensing signal. I f you have some great idea, please let me know, we will appreciate it very much. Thanks
Can you use an infrared link for the data?
wondering how much transfer efficiency is lost with the 2mm gap
It definitely sacrifices efficiency for convenience.
OK, so what frequency is it running at? SURELY you've got a frequency counter somewhere? ;-)
I've got a smartwatch that I want to try and fit one of these into. It currently uses a proprietary pin charging system and the internal battery says its 3.7v.
I was just wondering if you think this would still work
My BV9900-pro does not like wireless chargers.
I bought 2 chargers to try out. about $30 each.
I gave up on them due to them tripping the thermal sensor in the phone, melting the plastic case or both.
I never had that issue with a standard pad. Maybe because it was a lower power pad.
My previous Samsung phone came with a round charging pad and the rectangular phone had to be placed somewhat off center and very specifically on the charger in a certain way otherwise it wouldn't work. No thanks!
I missed the measurement of the frequency the LC is tuned to.
...we can utilize this tech to remote control with rechargeable batteries to turn relays on appliances like tv..so we could eliminate stanby powers needed to turn on tv for example..this makes appliances more power efficient and lightnings surge protected.. isolated from the grid until Its actually used..remote powerup within 10 meter range..
If its output is 4.2V then it is no use for charging a phone wirelessly? Can it be made to charge a phone? Or have I missed something? It would be good it it would put some charge into a phone during the night, just drop the phone and it would charge when not being used, slowly I must admit, but my phone sits about a lot doing nothing when it could be hacked to charge during this time!
Thanks Big Clive.
Would this charge up a 3.7v 2200 mAh 18650 battery correctly boss ?
I recently had to replace my phone and got the Samsung S21FE for one main reason, but secondary reason is for NFC (near field communication) for touchless pay). Looked into it in 2018 but my G6 from Motorola didn't have that, let alone wireless charging and at the time, it was looking like I could not use my debit card, with it as the software was not compatible with my card. Now, my credit union can accept Samsung, Google and at least 2 other tap to pay software so I'm setting that up. At that point, I didn't realize that you likely could change out the tap to pay software out even then.
The wireless charging is to reduce the strain/load of the USB for nearly daily charging of the phone (4500mh) battery and Snapdragon 888 processor means roughly a day of use between charges. At 5000Mh battery on the slower processor of my g6 meant a day and a half of use between charges when new but the failures was the USB port becoming loose and charging capabilities ceased to work, on both phones, one I bought new, the other a reman unit to replace the first phone and that second phone was acquired in January and the port was not as tight when I plugged in the USB cable to start with and by March, had failed to charge, so the Samsung was procured. It is considered a mid tier phone, and was the ONLY one to have wireless charging, never mind it is only 10W, so not the fastest, but will charge my phone from roughly 5% in about 2 hours in any event.
Could you use it to make an alarm circuit for security system .
The receiver coil appears to be open circuit on the board.
No, it just has a "tail" that extends past the capacitor pad a bit. I'm guessing it's either for antenna tuning, or they copy-n-pasted the antenna and didn't clean up the extra.
Question: I want to installl a 10k type B linear potentiometer (I don't need audio logarithmic) inline to a mono out jack for a metal detector for headphones (no volume control). I'm going to put signal in to lug #1, out to jack from wiper lug #2. If I leave the third lug open (not grounded) will it damage the circuit?
You should just need the two connections. 10K might be a bit high.
@@bigclivedotcom That "You should" does not sound too confident. 🤔🤣
I'm just going to solder #3 to pot case then to pcb ground. What can it hurt? I
I saw a diagram for 5K for headphones, so I figured 10k to be safe. Also linear taper because I'm just setting it at one point (not blowing my eardrums).
I recently tried messing with one of those (the 5v buck version though, needed a longer range), and appears a series-connected loading LC performs much better than the parallel one they use. Why the parallel circuit? Just for getting rid of the extra diode?
I'm not sure why they specifically use the parallel format.
Amazon sells the same ic as a 300v wireless charging ic with "anti-foreign" function.
I wonder if China have their very own Clive.
Nice cutouts btw.
Thanks for your videos