Can anyone explain how an electric toothbrush charging system works? I know it uses inductive charging but I can't find a detailed explanation anywhere that really describes the process. How does it take 120V AC and turn it into 1.5V DC for the battery? How far can the voltage travel across the inductors? Could the inductors be 2 inches apart and still receive power? Does anyone know a place that describes the process?
Much thanx!!

 

Originally posted by machman@Mar 3 2006, 05:42 PM
Can anyone explain how an electric toothbrush charging system works? I know it uses inductive charging but I can't find a detailed explanation anywhere that really describes the process. How does it take 120V AC and turn it into 1.5V DC for the battery? How far can the voltage travel across the inductors? Could the inductors be 2 inches apart and still receive power? Does anyone know a place that describes the process?
Much thanx!!

[post=14596]Quoted post[/post]​

Try googling with the term "splash power" or you may want to try splash-power. This is the term I seen used to refer to the inductive battery charging technique.

hgmjr

 

Originally posted by hgmjr@Mar 3 2006, 05:54 PM
Try googling with the term "splash power" or you may want to try splash-power. This is the term I seen used to refer to the inductive battery charging technique.

hgmjr

[post=14597]Quoted post[/post]​

thanx for the reply. I am familiar with Splashpower but they don't explain the process as it is new patented technology. I am looking for something much more specific as I'm a novice electronics hobbyist trying to understand the process.

 

Originally posted by machman@Mar 3 2006, 07:06 PM
thanx for the reply. I am familiar with Splashpower but they don't explain the process as it is new patented technology. I am looking for something much more specific as I'm a novice electronics hobbyist trying to understand the process.

[post=14600]Quoted post[/post]​

I don't know for absolute certainty, but it seems like an ordinary transformer. The primary winding is in the base. The secondary winding is in the toothbrush. I think the geometry is two coils on a common axis, one inside the other.

In the toothbrush the AC voltage is rectified and used to charge a battery. When you remove the toothbrush from the stand and hit the button the battery drives the brush actuator. When done it goes back in the stand for another charge cycle.

That's my opinion, and I could be wrong.

 

Originally posted by Papabravo@Mar 4 2006, 10:18 AM
I don't know for absolute certainty, but it seems like an ordinary transformer. The primary winding is in the base. The secondary winding is in the toothbrush. I think the geometry is two coils on a common axis, one inside the other.

In the toothbrush the AC voltage is rectified and used to charge a battery. When you remove the toothbrush from the stand and hit the button the battery drives the brush actuator. When done it goes back in the stand for another charge cycle.

That's my opinion, and I could be wrong.

[post=14603]Quoted post[/post]​

Pretty much as you explained it. The one I pulled apart had a coil in the bottom and a small and very rough rectifier to charge the battery.

 

Originally posted by machman@Mar 3 2006, 04:06 PM
I am familiar with Splashpower but they don't explain the process as it is new patented technology.

[post=14600]Quoted post[/post]​

Patents are public record.

Splashpower patent at USTPO

another Spashpower Patent at USPTO

(Note, one needs a TIFF viewer to get full use of the USPTO website)

Looks to me like it works same as the toothbruch, but at a higher frequency (eliminating need for a core). The really cool part (from my point of view) is the automatic frequency control.

 

Hi

I too am a amateur and trying to build and test some electronic ckt as a hobby, and do understand the theory but need help on specifics.

For eg: In the primary side, there would be a switching ckt, <200KHz, and the secondary side a resonant circuit. If I use an air coil in the secondary is it enough or do we need a ferrite core?

Thanks

 

Patent 6,934,167 "Contactless electrical energy transmission" is good and not too complicated. I'm looking through it now.

I like this site for generating pdfs http://www.pat2pdf.org/
The text comes out as images though, so you can't search/select.