Question on Oral-B toothbrush charger

Has anyone used an Oral-B power toothbrush (7000 or 8000 series)? I have one and it uses normal 110V power to charge Ni-MH battery. The interesting thing is its charger interface. The charger base has a protruder and the toothbrush has a corresponding receptacle, which match each other for charging. However, both the protruder and the receptacle are made of plastic material, i.e. non-conductor. I measured them using my multimeter and it shows no voltage, no current and infinite resistance, confirming that they are indeed non-conductors. So the questions is, how is charging done with non-conducting interface?

You may reply here or to my mailbox, thanks.

Reply to
Zhang
Loading thread data ...

Probably like my Panasonic shaver... transformer halves with air-gap.

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
 Click to see the full signature
Reply to
Jim Thompson

"Zhang" schreef in bericht news: snipped-for-privacy@posting.google.com...

Ever opened a brush like that. Found a coil at the bottom that was connected to a rectifier and loading circuit. The loader provides a magnetic field of about 22kHz that is conducted by a kind of a pin that goes right through the center of the coil. You can see something of its working when you place the loader with a brush in place put on an steel (iron) surface. The load LED will dim.

petrus bitbyter

--
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
 Click to see the full signature
Reply to
petrus bitbyter

Transformer with air core? Hmm ... that sounds right.

The base has a block with size of a typical household transformer where the 110V comes in. It should be the place that transformes 110V AC to

1.2V AC, I can feel the heat by touching the cover.

The protruder/receptacle interface should then form another transformer where 1.2V AC is coupled into the second coil inside the toothbrush, and further rectified to 1.2V DC to charge the battery.

Considering the small size of that interface, it's pretty neat design.

Reply to
Zhang

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.