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RE: Inductive Sensing Design Challenge: USB Microphone based on the LDC1000 Inductance to Digital Converter (week 8 & 9)

vsluiter — Tue, 22 Jul 2014 09:21:47 GMT

4 mil (0.1mm) is very, very small. Itead does 0.15mm, but you might ask them what their limits are. They're quite fast in delivery if you pay for expedited shipment. You might also try WEDirekt, which is the webshop of Wurth Elektronik. More expensive than the Chinese pooling services, but they're in a better league of quality management [View:/resized-image/__size/16x16/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-e0705057-e3d2-4f84-a68c-922a079fbbad/contentimage_5F00_3.png:16:16]. They do provide 0.1mm trace width: WEdirekt – der Online-Shop von Würth Elektronik | Leiterplatten und Stencils ab 1 Stück | Platine, Leiterplatten, Protot…

RE: SteelQuad: Steel Quality Sensing Device (week 10)

vsluiter — Tue, 22 Jul 2014 09:17:39 GMT

Looks like an impressive amount of work. Could you link to a post that describes the target of your project? I'm falling a bit in the middle of your progress, would like to know what you're trying to achieve

RE: Inductive Sensing Design Challenge: USB Microphone based on the LDC1000 Inductance to Digital Converter (week 8 & 9)

DAB — Tue, 01 Jul 2014 18:03:20 GMT

Hi Sammy,

Unexpected delays are the bane of engineers world wide.

Keep persevering.

DAB

RE: SteelQuad: Steel Quality Sensing Device (week 5)

Kilohercas — Mon, 16 Jun 2014 12:40:29 GMT

I can't get my head around your idea. From my point of view, you will try to evaluate metal quality where you can assess it by means of measuring it's effect to inductive coil.
My question is how can you get any usefull information about metal properties based on permeability, if different compositions and other fact will alter greatly your measurement. In the over words, you will be measuring something that is function of many things, and you can't control or know about them. as example you will measure L(μ), but μ is function of many variables, so what you end up is L(μ(x,y,z,t,f)). Or maybe i just don't understand how you are going to achieve your goal

RE: SteelQuad: Steel Quality Sensing Device (week 4)

DAB — Sat, 31 May 2014 19:12:25 GMT

It sounds like you are organized to begin testing.

Can't wait to see what you come up with.

DAB

PS, have you thought of running some measurements while the cement cures?

You could get some valuable data by seeing if the values change over the 30 day curing cycle.

RE: Inductive Sensing Design Challenge: USB Microphone based on the LDC1000 Inductance to Digital Converter (week 5)

DAB — Fri, 30 May 2014 20:14:59 GMT

Hi Sammy,

Good post.

Is the linearity of detection distance due to the algorithm in the sensor or just the signal response from the software?

I wonder if you can set up the sensor to a log scale so that you can get higher resolution over a smaller range?

DAB

RE: Let's make some music

shabaz — Sat, 24 May 2014 16:17:35 GMT

Probably, it will sound different (since the two methods are measuring in different ways - an electric guitar cuts a certain amount of flux (so the magnet characteristics have an impact too) as the wire vibrates (so it depends on the wire position as it vibrates), that may be very different to the field from the coil with no magnet, using the LDC1000. I'm sure it will work, but as a result the sound may have different harmonics (which are probably the reason expensive pickups cost a lot).

It is an interesting use-case however.

RE: More Music

D_Hersey — Sat, 24 May 2014 16:16:25 GMT

Leon Theremin got his patent in 1928. Lenin, it turns out, was a good player.

RE: Let's make some music

D_Hersey — Sat, 24 May 2014 15:33:38 GMT

Good idea! Why not just separate the pickup coils and use those for your inductor.

RE: How do you like your Steak ? What about your breakfast egg ?

michaelwylie — Sat, 24 May 2014 05:11:48 GMT

This is great. Can't wait to see your results.

RE: Inductive Sensing Design Challenge: USB Microphone based on the LDC1000 Inductance to Digital Converter (week 4)

vsluiter — Thu, 22 May 2014 19:54:21 GMT

Have you thought about a flexible polymer carrying film (or some other suspension), with a ferromagnetic center? That way you might be able to get more excursion with a smaller diameter film.

RE: Inductive Sensing Design Challenge: USB Microphone based on the LDC1000 Inductance to Digital Converter (week 4)

DAB — Thu, 22 May 2014 18:15:39 GMT

Part of the challenge is to try many different designs.

You never know when an unlikely combination of materials can give you a neat affect. Ie. the Thomas Edison approach to science. [View:/resized-image/__size/16x16/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-9ff0572e-1372-4426-aa7f-135967ba90ce/contentimage_5F00_938.png:16:16]

After all, its not a good experiment unless something loses the magic smoke.

DAB

RE: Inductive Sensing Design Challenge: USB Microphone based on the LDC1000 Inductance to Digital Converter (week 4)

vsluiter — Wed, 21 May 2014 20:36:41 GMT

Good piece of reference material!!

Are you able to purchase these thin films from somewhere? Would you be able to verify what you've found?

RE: Inductive Sensing Design Challenge: USB Microphone based on the LDC1000 Inductance to Digital Converter (week 4)

michaelkellett — Wed, 21 May 2014 17:02:37 GMT

Hello Sammy,

I'm worried about the graph that shows thicker membranes being displaced more - it doesn't seem right - the thicker the membrane the stiffer it will be and the displacement will be lower. I've only looked briefly at this (have to go home), I'll try to look again tomorrow.

RE: Inductive Sensing Design Challenge: USB Microphone based on the LDC1000 Inductance to Digital Converter (week 2 & 3)

michaelkellett — Thu, 15 May 2014 08:12:38 GMT

What frequency range do you expect your microphone to work over ?

It looks much too big for normal audio range.

It's a while since I designed anymicrophones and I never designed any moving iron parts but this extarct from "Electroacoustics" , (written by ML Gayford and published by STC/Newnes Butterworths in 1970) may help.

[View:/resized-image/__size/620x465/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-eaf99c7b-44a5-462e-b78e-46918af73efc/1030.contentimage_5F00_178670.jpg:620:465]

Notice how small the parts are, yet this was a large device by modern standards. The (big) problem with moving iron microphones is the mass of the iron. Your inductance sensor will be more sensitive with a larger mass to detect (although the target does not need to be ferromagnetic it must conduct well and very thin films won't be good enough - try copper foil.)