|
Posted by Clark Magnuson on July 4, 2008, 3:56 pm
Please log in for more thread options
I have an old worn out Sonic Care brush head, with two magnets sticking
out the bottom.
The wife issued me a new design brush head that is differently shaped.
She breaks off the magnets for the refrigerator.
I decided to cut the plastic off and figure out how it works.
There are two magnets attached via a long piece of metal to the brush.
The long piece is welded via a pin to a U channel piece of metal.
The whole thing seems too stiff to move. I gave up.
I called up Dan and he said:
The battery in the handle is switched by two low sat transistors in push
pull on the primary of a transformer. The secondary is a capacitor that
forms a resonant tank with the inductance. The magnetic core is open and
couples through plastic to the two magnets on the brush head. The brush
head magnets are mounted on metal, that completes the magnetic loop. The
action on the two magnets is side to side. The magnets do not touch
anything, but vibrate. The pin in the brush head acts like a torsion
bar. The resonant frequency of the inductance and capacitor through the
turns, must be the same frequency as the resonate frequency of the brush
bar mass with the torsion bar. The U channel must be stiffly mounted to
the handle by tightening the big plastic nut. The electrical resonance
is high Q and so low loss. The mechanical resonance is high Q and so low
loss, but the cheek can dampen the side to side motion, and that is why
there is a plastic shroud approaching the brush.
The new brush head design does not need a shroud. It does not have a
stiff torsion bar pin, but rather a translational pivot point. This
allows the brush head to move rotationally instead of side to side. The
new brush then compresses into the tooth and brushes side to side with
each stroke.
What does it all mean? Dan is in demand for defibrillator design,
hydroplane carburetor design, amateur TV transmitter design, and a few
other things, but he seems to know how everything works, relative to my
primitive understanding. It always amazes me how I can pick the topics
and then he has so much depth on the topic.
|
|
Posted by RB on July 7, 2008, 2:08 pm
Please log in for more thread options
Clark Magnuson wrote:
> I have an old worn out Sonic Care brush head, with two magnets sticking
> out the bottom.
>
> The wife issued me a new design brush head that is differently shaped.
> She breaks off the magnets for the refrigerator.
>
> I decided to cut the plastic off and figure out how it works.
> There are two magnets attached via a long piece of metal to the brush.
> The long piece is welded via a pin to a U channel piece of metal.
> The whole thing seems too stiff to move. I gave up.
>
> I called up Dan and he said:
> The battery in the handle is switched by two low sat transistors in push
> pull on the primary of a transformer. The secondary is a capacitor that
> forms a resonant tank with the inductance. The magnetic core is open and
> couples through plastic to the two magnets on the brush head. The brush
> head magnets are mounted on metal, that completes the magnetic loop. The
> action on the two magnets is side to side. The magnets do not touch
> anything, but vibrate. The pin in the brush head acts like a torsion
> bar. The resonant frequency of the inductance and capacitor through the
> turns, must be the same frequency as the resonate frequency of the brush
> bar mass with the torsion bar. The U channel must be stiffly mounted to
> the handle by tightening the big plastic nut. The electrical resonance
> is high Q and so low loss. The mechanical resonance is high Q and so low
> loss, but the cheek can dampen the side to side motion, and that is why
> there is a plastic shroud approaching the brush.
>
> The new brush head design does not need a shroud. It does not have a
> stiff torsion bar pin, but rather a translational pivot point. This
> allows the brush head to move rotationally instead of side to side. The
> new brush then compresses into the tooth and brushes side to side with
> each stroke.
>
> What does it all mean? Dan is in demand for defibrillator design,
> hydroplane carburetor design, amateur TV transmitter design, and a few
> other things, but he seems to know how everything works, relative to my
> primitive understanding. It always amazes me how I can pick the topics
> and then he has so much depth on the topic.
That's about how I figured it worked. Love mine, but after 6 years or
so I've given up on it crapping out and giving me an excuse to take it
apart.
|
|
Posted by Clark Magnuson on July 10, 2008, 9:49 am
Please log in for more thread options RB wrote:
>>
>> The new brush head design does not need a shroud. It does not have a
>> stiff torsion bar pin, but rather a translational pivot point. This
>> allows the brush head to move rotationally instead of side to side.
>> The new brush then compresses into the tooth and brushes side to side
>> with each stroke.
>
> That's about how I figured it worked. Love mine, but after 6 years or
> so I've given up on it crapping out and giving me an excuse to take it
> apart.
Yesterday, I talked to Bernhard Sandburg, who used to be an engineer at
Sonic Care, he calls the tri pod inside the new brush head "the spring"
and says it is laser trimmed. I thought it just provided stiffness, but
that does not account for it's shape.
|
| Similar Threads | Posted | | Re: Health Care | September 16, 2008, 9:09 pm |
| Re: Health Care | September 17, 2008, 6:47 pm |
| Re: Health Care | September 24, 2008, 12:38 am |
| Re: Health Care | September 24, 2008, 12:53 am |
| Re: Health Care | October 20, 2008, 7:33 pm |
| Re: OT - Neocons to tax health care | February 28, 2007, 10:19 am |
| Someone Besides Me Asked about Deburring Insides... | March 15, 2007, 4:30 pm |
| Care packages to soldiers political | November 18, 2007, 5:49 pm |
| Re: Gauge block care and useage | March 12, 2006, 11:28 am |
| Re: Gauge block care and useage | March 13, 2006, 5:15 pm |
|
|
Yahoo! 
Google 
Windows Live 
del.icio.us 
digg 
Netscape 
XML Sitemap
> out the bottom.
>
> The wife issued me a new design brush head that is differently shaped.
> She breaks off the magnets for the refrigerator.
>
> I decided to cut the plastic off and figure out how it works.
> There are two magnets attached via a long piece of metal to the brush.
> The long piece is welded via a pin to a U channel piece of metal.
> The whole thing seems too stiff to move. I gave up.
>
> I called up Dan and he said:
> The battery in the handle is switched by two low sat transistors in push
> pull on the primary of a transformer. The secondary is a capacitor that
> forms a resonant tank with the inductance. The magnetic core is open and
> couples through plastic to the two magnets on the brush head. The brush
> head magnets are mounted on metal, that completes the magnetic loop. The
> action on the two magnets is side to side. The magnets do not touch
> anything, but vibrate. The pin in the brush head acts like a torsion
> bar. The resonant frequency of the inductance and capacitor through the
> turns, must be the same frequency as the resonate frequency of the brush
> bar mass with the torsion bar. The U channel must be stiffly mounted to
> the handle by tightening the big plastic nut. The electrical resonance
> is high Q and so low loss. The mechanical resonance is high Q and so low
> loss, but the cheek can dampen the side to side motion, and that is why
> there is a plastic shroud approaching the brush.
>
> The new brush head design does not need a shroud. It does not have a
> stiff torsion bar pin, but rather a translational pivot point. This
> allows the brush head to move rotationally instead of side to side. The
> new brush then compresses into the tooth and brushes side to side with
> each stroke.
>
> What does it all mean? Dan is in demand for defibrillator design,
> hydroplane carburetor design, amateur TV transmitter design, and a few
> other things, but he seems to know how everything works, relative to my
> primitive understanding. It always amazes me how I can pick the topics
> and then he has so much depth on the topic.