Looking for High Frequency MEMS Accelerometer

[Klaus Kragelund]

Hi

I have an application in which I'm looking for an MEMS accelerometer,
that can handle >100G and has a frequency 3dB cut-off at 50kHz.

Anyone know of such a thingie?

Thanks

Klaus

 

[Spehro Pefhany]

Hi

I have an application in which I'm looking for an MEMS accelerometer,
that can handle >100G and has a frequency 3dB cut-off at 50kHz.

Anyone know of such a thingie?

Thanks

Klaus

Why MEMS? I don't think this is a problem for a piezoelectric
accelerometer. You want something with a resonant frequency in the
200kHz range.

You could ask about the ADXSTC3-HG, but I doubt you'll be able to buy
it.


Best regards,
Spehro Pefhany

 

[Klaus Kragelund]

You mean you are going to smack something into the ground with 100G
at 50.000 times per second?
How much energy does that take?

Well, the 100G could be at 100Hz, and only small signal at 50kHz.
Still needs to be able to handle 100G then

/Klaus

 

[linnix]

Well, the 100G could be at 100Hz, and only small signal at 50kHz.
Still needs to be able to handle 100G then

/Klaus

Basically, you want to by-pass the filter and track the third order
motion, just as we do. 100G is not a problem, but all the commercial
chips come with Bessel filters. You need access to the bare sensor.
Are you ready and willing to do a custom sensor?

 

[dalai lamah]

Un bel giorno Klaus Kragelund digitò:

Well, the 100G could be at 100Hz, and only small signal at 50kHz.
Still needs to be able to handle 100G then

Use two different accelerometers, one for the slow 100G and one for the
fast small G. I think you will save a lot money.

 

[linnix]

Un bel giorno Klaus Kragelund digitò:


Use two different accelerometers, one for the slow 100G and one for the
fast small G. I think you will save a lot money.

And get nothing for the small G. You might as well replace it with a
motion switch, since it will be at maximum all the time.

 

[linnix]

You would have to make some mechanical filter that filters out the low
frequency vibrations, and put the high frequency sensor after that.
Some sort of acoustic coupler perhaps?

If such filter exists, you would not need the 100G sensor in the first
place.
Yes, if you have a fast 100G sensor, you can build the active
mechanical filter.

 

[dalai lamah]

Un bel giorno linnix digitò:

And get nothing for the small G. You might as well replace it with a
motion switch, since it will be at maximum all the time.

I thought it was implied by the OP that the two dynamics won't present
together at a time, but you are probably right.

 

[[email protected]]

Hi

I have an application in which I'm looking for an MEMS accelerometer,
that can handle >100G and has a frequency 3dB cut-off at 50kHz.

Anyone know of such a thingie?

Thanks

Klaus

Are you gonna launch a Sprint ABM? Ohh let us know when!

 

[linnix]

Sounds more like a collision sensor.

Yes, impact analysis requires fast responses between 99.5g and 100.5g.
No, you can't build it with a 100g and 1g combined.

 

[whit3rd]

at 50.000 times per second?
How much energy does that take?

Last time I did it, the motor was rated at 500W.
The "something" was a titanium exponential horn, and
the tip smacked into diamond dust atop a piece of something
rather hard... this goes by various names, 'impact grinding'
and 'ultrasonic drilling' .

The tip was only a few grams, though, and wasn't
really compatible with accelerometers (how would you
attach one so it didn't flop loose?)

 

[JosephKK]

Well, the 100G could be at 100Hz, and only small signal at 50kHz.
Still needs to be able to handle 100G then

/Klaus

I have not seen MEMS accelerometers that can do both, perhaps you can
try piezoelectric accelerometers with fast charge amplifiers.