Questions tagged [wireless-charging]
The wireless-charging tag has no usage guidance.
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Why are wireless chargers inefficient?
In the current market, the chargers are only 40-50% efficient.
How much is the conversion and flux losses during transmission?
Is there any way to improve the overall efficiency?
Can a ferrite ...
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2answers
65 views
Wireless Electricity Transmission model not working. Why?
I made wireless electricity transmission model using the principle of magnetic inductive coupling to transfer electricity between two separate coils. The model is very simple, known to everyone and ...
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456 views
Inductor and capacitor for energy storage instead of battery
I am trying to see if it would make sense to use a LC network to store small amount of electrical energy (500 mWHr or less) as an alternate of a 3.3 V battery. What I understand is that L and C are ...
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80 views
Magnetic Field Interfering with Radio Waves
i am currently building a device that requires a NRF24L01 module to send radio waves to another NRF24L01 to be picked up and interpreted. This is a using an arduino running a code to transmit data via ...
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Is this quote about interference from wireless charging coils accurate?
This blog post suggests that apple dropped their promised AirPower wireless charging mat because it didn't pass EMI standards, specifically due to the (unconfirmed) idea that they were using a large ...
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2answers
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What would happen if you accidentally casually put your apple watch on a wireless charger meant for phones or other higher power devices for hours? [closed]
What would happen if you accidentally, casually (because they're supposed to be so convenient!) put your apple watch on a wireless charger meant for phones or other higher power devices for hours? Or ...
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1answer
32 views
Battery free TPMS
I am doing a report about wireless TPMS, and I heard about products where the sensors in the valves do not need batteries at all (operate and transmit the data). Is that correct?? have you encountered ...
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1answer
30 views
Hooking into Qi charger status LED to power something more
I have a Qi charging module and I want to light up a higher-power string of LEDs when my phone is charging through it.
The module has a blue status LED to show it's charging, which I think is where ...
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1answer
74 views
Coupling coefficient variation in Wireless power transfer
Question regarding WPT compensation topologies.
I'm trying to make a inductive wireless power transfer system where the RX coil can move quite conisderably relative to TX coil and still transfer ...
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1answer
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Connecting transmitter coil to the oscillator
Hi guys i have two problems.
1.Where to connect the transmitter coil to the oscillator part?
2.How to make the output of the oscillator stronger? because someone told me that the output coming from ...
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1answer
55 views
WPT compensation topologies
I'm experimenting with compensation topologies for inductive WPT systems and have a small confusion.
The general WPT industry uses compensation networks to cancel out reactive components in the ...
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2answers
368 views
Mutual inductance vs coupling coefficient
Question regarding this and this question about mutual inductance and coupling coefficient.
I'm trying to analyse a two coil system:
It consists of two coils like in the picture with 2 cm air gap ...
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1answer
97 views
How can I model and simulate a resonant inductive square spiral coil in MATLAB?
I was wondering if it was possible to model and simulate my WPT system in MATLAB to determine if my analytical calculations are correct. I want to model my system in MATLAB as I have seen on MathWorks ...
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Minimal components for lighting an LED via wireless power transfer
I understand the basic concept of wireless power transfer.
I wanted to make some wireless LEDs (Similar to this concept) and was trying to figure out the minimum component count I required in order ...
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1answer
270 views
why do resonant inductive coupling circuit operate at high frequencies?
Just as the title says. Whenever I read a research paper on wireless power transfer via resonant inductive coupling the authors just mention frequencies that range in the kHz and Mhz range, but none ...
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1answer
46 views
Wireless power through air [duplicate]
I know this might be far fetched. In normal everyday life, we have huge amounts of data traveling through the air in the form of electromagnetic radiation. But what if instead of transmitter data ...
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260 views
Wireless power transfer - Inductive vs. resonant mode
When talking about how wireless power transfer is done, the standards (e.g Qi) distinguish between inductive and resonant mode. (Link)
They claim that when the units are in very close proximity it is ...
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1answer
75 views
How does this circuit output 25kHz?
This circuit doesn't use a gate drive, so I am trying to understand how it can output 25kHz. A friend of mine told me that it does so with the use of LC resonance; the capacitor and inductor next to ...
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1answer
57 views
Inductive Charging 2 layer coil transfer to 1 layer receiver. Any issues?
I am looking to incorporate a inductive charging mechanism into a project I’m working on. On the receiving side I only have room for a single layer coil design. For my transfer side I have more ...
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2answers
274 views
Extend wireless Qi charging with a coil in the middle
I have a question regarding wireless charging. Traditionally, you have two coils, the charger and the receiver for wireless charging with Qi (from what I understand).
Would you be able to have an ...
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459 views
Does wireless charging degrade battery life? [closed]
Does a design using wireless charging such as QI effect the longevity/health of lithium-ion batteries such as those found in modern consumer electronics devices?
What special considerations must be ...
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1answer
129 views
Qi charging multiple devices with single transmitter
I am looking for a Qi charging compliant transmitter and have found kits from different manufacturers like ST/TI/Microchip. These kits have one receiver and are tuned to work together.
How can I ...
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3answers
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Auxiliary circuit to reduce power losses in idle stage of this oscillator (wireless power application)
I am trying to implement the following resonant oscillator for wireless power transfer application. There will be a secondary coil coupled with Lp. .
Reference - WPT Application Note
One of the ...
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1answer
59 views
Wireless arduinos
I am currently in the design phase of a project that is using 3 arduino nanos controlling 2 small stepper motors (28BYJ-48) each.
There is a lot of moving parts where some movements are continuous and ...
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2answers
171 views
How does the diagram really work? [closed]
Good afternoon, I am a high school student and in my scientific fair project, I would like to do an experiment about wireless energy.
I want to implement the resonant inductive coupling.
According ...
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3answers
385 views
Why is wireless power transfer done between two coils at their self-resonant frequency?
I was reading this paper about wireless power transfer via strongly coupled magnetic resonance:
http://www.ijirem.org/DOC/1_Wireless%20Power%20Transfer%20via%20Strongly%20Coupled%20Magnetic7a7f01ee-...
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How does the change of load on the Rx side influence the Tx resonance voltage in a wireless powering sysytem
As the circuit shows, U = 5V toggling the polarity in 10KHz. When IL is changed from less than 1mA to 20mA, the P-P voltage of the Tx coil will increase. How should I understand the phenomenon? I have ...
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QI COMM-Signal Simulation ltSpice
For a school project (Wireless Charging), I have to filter out and display the communication signal (2KHz) between transmitter and receiver from the Power Signal (100KHz). For this I have set up the ...
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1answer
197 views
Wireless charging
I am trying to make a circuit to transfer power from one coil to another
I have tried difference frequencies here are the results
Fun Fact: When I am producing frequencies between 20Hz and ...
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1answer
82 views
Power IR2110 from a low voltage AC Source
I am trying to power the IR2110 using an AC Source. However, this source is also connected to a full wave bridge rectifier that's going to supply a controlled buck converter.
I tried using a voltage ...
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3answers
742 views
Using a capacitor instead of a coil for wireless charging?
This might sound like a stupid question, but I'm kinda interested in a detailed explanation.
So while inductive charging is rather ubiquitous, things like electric toothbrushes and Qi chargers come ...
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1answer
80 views
Fast charging ports under the hood - technical details behind the standards? [closed]
There are a few things I noticed and examined for two different fast charging standards:
MediaTek PumpExpress works without any data communications with the charger. Output 2 from my USB multimeter ...
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1answer
106 views
How should you position two flat-wound spiral coils for the best coupling?
I created two flat wound-spiral coils (also known as bifilar coils). The transmitter coil I made with an outer diameter of 10 inches and an inductance of 3 mH. The receiver coil I used a much smaller ...
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1answer
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Slayer Exciter Interfering With Voltage Measuremnet With Multimeter
I've built myself a slayer exciter and I am trying to measure the output voltage. I've created a coil with approximately 10 turns and soldered a bridge rectifier to the ends of the coil so I can ...
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1answer
84 views
How can I build my own wireless charger for my cellphone? [duplicate]
I am designing a wireless charger for my cellphone, Where my Primary coil is energised with 1.5V and 0.3A, Where I have used a transistor to turn it on and off at a frequency of 1Mhz.
In the secondary ...
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1answer
118 views
Do these waveforms look appropriate for charging an 11.4 V, 3830 mAh lithium ion battery?
I'm putting together a wireless power transfer based battery charger to charge an 11.4 V, 3830 mAh battery from the output of a 15 V voltage regulator I made.
Due to a limited understanding of ...
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1answer
493 views
Powering a motor through wireless electricity [closed]
simulate this circuit – Schematic created using CircuitLab
simulate this circuit
Schematic redrawn by Transistor. OP to edit or delete as required.
I have a wireless electricity transmission ...
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1answer
56 views
Wireless Powering Products
Are there wireless powering products for a distance of 50 cm? I want to design a sensor tag where it can be recharged wirelessly. Is that possible?
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128 views
wireless power transmitter produces voltage but nothing picked up on receiver
Here's another attempt I made on wireless power:
I borrowed ideas from http://4hv.org/e107_plugins/forum/forum_viewtopic.php?74096 but due to limited stock on hand, I had to use what I can.
I used ...
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1answer
111 views
Wireless charging circuit
I'm designing a wireless charging circuit and i've noticed that on the internet there are two types of circuits:
For some schematics the LC circuit is made in series resonace, in some in parallel.
...
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616 views
How to convert from power signal received by Antenna to voltage signal?
I am considering wireless transmission.
Let us define a cosine signal with frequency 2.4 GHz, i.e.
$$s(t) = A\cos(2\pi ft),$$ where $$f=2.4\times10^9.$$
Let us assume that when TX transmits the ...
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2answers
91 views
why my laptop can't use wireless charging technology? [closed]
we start to deal with wireless charging technology in recent years with the booming of smart phones
why wasn't it possible with laptops?
does the smart phone's battery differ from laptop's?
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1answer
301 views
In a single diode rectifier circuit, is capacitor offering additional energy to Load?
I am a graduate student majoring in electrical engineering.
Now, I am studying about wireless power transfer and energy harvesting.
While reading a paper written by Bruno Clerckx, who is senior member ...
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232 views
Is a battery management system necessary for wearables? [closed]
My team and I are working on developing a wearable device (like a heart rate monitor with IP68 dust/waterproofing) and we're utilising wireless charging for our 3.7V 350mAh non-removable battery.
We'...
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2answers
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Is it possible for a Wireless device charging pad to fry RFID / Contactless cards?
Lets say for example that a person has a wireless charger in their car centre console (an option on some new cars)
This person puts their wallet and phone there and the charger kicks in. (wallet ...
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0answers
358 views
Significant voltage drop across IGBT
I'm using an IGBT in a wireless charger circuit as a swtich to send 'pulses' of power across the gap. I have 14V coming from the mosfet driver and I can see around 5v on the collector. I have the ...
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3answers
9k views
How to build a self-made Qi compatible (wireless) charger
So I recently discovered that my phone, a Nexus 5, has Qi wireless charging capabilities. I was wondering if it is possible to make my own charging coil with 24/26awg wire that would look something ...
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276 views
Receiving 27MHz wireless power
I am designing a high frequency passive RFID tag-like device that receiving 27MHz wireless power, use it to power a onboard MCU and a low power transmitter. The estimated current drain is about 50mA. ...
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Inductive charging problem
I am fairly new to electronics and I recently made an inductive charger that transfers 18 volts over a couple mm from 120 volts. The problem I am having is that while the voltage transfer is good, the ...
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1answer
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Is it possible to redesign a portable electronic device such that it can be charged by a domestic microwave oven?
Soon after iPhone 6 was introduced there was a prank claiming that the smartphone can be charged by leaving it in a running domestic microwave.
TL;DR don't do it, it is very, very unsafe. There's a ...
