I was wondering how efficiently the inductive phone chargers worked, so I got a couple of modules off ebay and a receiver plate to take to bits. They do seem to communicate with each other, rather than just pumping current into any coil that comes near.
The transmitters seemed to use what appeared to be a microcontroller controlling an H-bridge driver that then drove the coil via a paralleled cluster of capacitors. The receiver had a modest amount of circuitry in it with what appears to be a dedicated QI receiver chip, possibly by Texas Instruments.
Efficiency was 50% at best and got MUCH worse as the coils were parted.
Both the transmit and receive coils are both backed by a layer of ferrite material. In the case of the transmitter it was a hard ferrite disk and on the receiver it was a thin brittle layer sandwiched between two layers of plastic and with the coil stuck to the front.
Neat enough toy for inductive coupling of power. Perhaps ideal for charging circuits mounted inside waterproof cases.
The transmitters seemed to use what appeared to be a microcontroller controlling an H-bridge driver that then drove the coil via a paralleled cluster of capacitors. The receiver had a modest amount of circuitry in it with what appears to be a dedicated QI receiver chip, possibly by Texas Instruments.
Efficiency was 50% at best and got MUCH worse as the coils were parted.
Both the transmit and receive coils are both backed by a layer of ferrite material. In the case of the transmitter it was a hard ferrite disk and on the receiver it was a thin brittle layer sandwiched between two layers of plastic and with the coil stuck to the front.
Neat enough toy for inductive coupling of power. Perhaps ideal for charging circuits mounted inside waterproof cases.
how would a cracked ferrite plate make a difference? mine is and i don't know if it matter at all?
Be careful of the China versions. They turn into an oven lol.
chee
Hi Clive, the Qi charger is pronounced "Chee"
Its OK to call it QI
Damn, are you stalking me? I just received my Qi charger from Banggood for modification and use with a QuadLock case.
(Yes I know video was filmed years ago)
Modern high-quality Qi chargers, with the receiver built into the phone, when alligned properly, will operate at about a 70-75% efficiency.
However this can drop significantly when they are lower quality and not alligned properly.
Five years later and inductive charging is still less efficient than a piece of wet string.
Is that fat charging wire on the ferrite Litz wire, woven to remove skin effect?
NEW COMMENT OLD VIDEO 🙂 I have ordered a few of these but not yet received them. As far as the efficiency goes, would it have been a better test back then to try a bigger load than an LED. The efficiency may increase a bit with a bigger load…. Watch your channel a lot ! Thanks Clive. !
wasting time
I love my inductive charger for my S8. It maybe inefficient, but it's so convenient. Couldn't imaging going back to plugging in again.
1cm is a 2,54th of an Inch
Hello bigclive, I recently got myself a Braun Oral-B electric toothbrush. It came with an option of getting a NiMH or (a much more expensive) Li-ion battery. I noticed that it used induction charging. They've been on the market for 4-5 years now and are getting fairly cheap. I was thinking it might be a good idea to tear one of these down? I'd be interested in that.