Elektrosluch 2 - my first crowd-funded project

[mrkva]

Hey guys,

maybe some of you will like my simple project. It is named Elektrosluch 2 - a device for listening to electromagnetic fields.
http://www.indiegogo.com/projects/elektrosluch-2/x/6356259

Regards,
Jonas

[dexters_lab]

interesting project

do you see this has any practical use or is it just for fun?

[mrkva]

Most of the customers from previous version were experimental/electronic musicians, getting inspired by these EMI sounds.
But I can see it being useful for 'measuring' EMI around your designs (in audio hardware for example). Discovering potential problems. Also, you can check where the wiring goes in the wall (by listening to 50/60 Hz ).

[mrkva]

Maybe I should send one to Dave? It could be fun to see what kind of sounds all his measurement equipment makes Displays are fun in particular.

[scientist]

He'd probably roast it, but it's worth the design criticism!

[mrkva]

Why do you think so?

[jucole]

I love it! -  I see the attraction for musicians - it produces some great weird sounds!  don't forget to punt it to the ghost community as an audible ghost detector! :-)

[peter.mitchell]

My design thoughts;

I say toss the 9v battery and use 2x AAs, and a boost converter, so many reasons to do this;
AAs are cheaper and more energy dense than 9v batteries
Rechargeable AAs are very reliable and chargers are common compared to 9vs
You can use 2x 1x AA battery holders, and put you components down the middle, so they act as protection
The cost difference between a 9v battery and the components for the boost converter are about the same - except the boost converter components will last forever.

Other things;
Use a slide switch, i mean, you don't need the massive current handling of the toggle switch, plus it will be harder to accidentally turn off and be less awkward to hold, also easier to manufacture and possibly cheaper.
No idea what op amp you're using but I hope it's one with decent current output, people might stick massive headphones on this thing, they will probably want them driven and if it's used as a "tool" potentially a small speaker would be wanted to be driven.  Check out this one
If you used a 2+mm thick PCB, and used full SMD you could get away without a back cover, instead just using the PCB.

I know this is all a bit late now but eh.

[mrkva]

My design thoughts;

I say toss the 9v battery and use 2x AAs, and a boost converter, so many reasons to do this;
AAs are cheaper and more energy dense than 9v batteries
Rechargeable AAs are very reliable and chargers are common compared to 9vs
You can use 2x 1x AA battery holders, and put you components down the middle, so they act as protection
The cost difference between a 9v battery and the components for the boost converter are about the same - except the boost converter components will last forever.

Other things;
Use a slide switch, i mean, you don't need the massive current handling of the toggle switch, plus it will be harder to accidentally turn off and be less awkward to hold, also easier to manufacture and possibly cheaper.
No idea what op amp you're using but I hope it's one with decent current output, people might stick massive headphones on this thing, they will probably want them driven and if it's used as a "tool" potentially a small speaker would be wanted to be driven.  Check out this one
If you used a 2+mm thick PCB, and used full SMD you could get away without a back cover, instead just using the PCB.

I know this is all a bit late now but eh.

Hey thanks!

My answers - boost converter - wouldn't that be noisy and thus ruining the actual performance of the product? I amplifying EMF, and when my own circuit is creating one... Also, I don't have good experience with boost converters and audio (or expertise for doing it properly). And it'd probably take more space - bigger PCB - higher costs. Extra assembly time.

Toggle switch is esthetically decision, simply looks and feels better. And trust me it won't turn on accidentally, it is quite stiff.

I don't think full SMD is nice for components like jacks, pots etc., especially when their only support point is the PCB. I don't think they would last as much as proper THT ones.

Anyway, thanks for the comments

Regards,
Jonas

[mrkva]

How the final product looks like, btw.

[scientist]

Why do you think so?

Dave pretty much roasts everything.

[dexters_lab]

back when i was wielding screwdrivers in my teens i started digitally recording, isolating and filtering strange mechanical sounds like hard and floppy disk drives, tape decks, switches etc so this device was of interest

i would have bought one but i'm saving ££ for my holiday!

[mswhin63]

Bit confusing, I haven't been n this site for a while, first appearance the symbol you are using is concerning as it is a copyright symbol international hearing impairment symbol.

In Australia at least the copyright is managed by The Deafness Forum of Australia. There are widespread organisations that use that symbol.

I have used this type of equipment for the last 12 years servicing a testing Audio induction Loop Systems. Very common product and a lot of very cheap kits that can be purchased at least in Australia.  I personally have a professional version that is set up for the Australian Standard 61088.4 for testing loop systems.

I got out of the audio aspect of the industry approx 2 years ago, so you have nothing to fear over the symbol as I couldn't give a rats arse any more, just careful of the commercialisation. Test it on installed Audio Loop System usually in cinemas and if it picks up the sound of the theatre then you can use the symbol, although not sure if the colour will impact. (Yes the bloody colour is copyrighted too)

[mrkva]

Bit confusing, I haven't been n this site for a while, first appearance the symbol you are using is concerning as it is a copyright symbol international hearing impairment symbol.

In Australia at least the copyright is managed by The Deafness Forum of Australia. There are widespread organisations that use that symbol.

I have used this type of equipment for the last 12 years servicing a testing Audio induction Loop Systems. Very common product and a lot of very cheap kits that can be purchased at least in Australia.  I personally have a professional version that is set up for the Australian Standard 61088.4 for testing loop systems.

I got out of the audio aspect of the industry approx 2 years ago, so you have nothing to fear over the symbol as I couldn't give a rats arse any more, just careful of the commercialisation. Test it on installed Audio Loop System usually in cinemas and if it picks up the sound of the theatre then you can use the symbol, although not sure if the colour will impact. (Yes the bloody colour is copyrighted too)

Hey,

I took the bits for the logo from here:
http://en.wikipedia.org/wiki/File:International_Symbol_for_Deafness.jpg
Which claims to be in public domain. "Any traffic control device design or application provision contained in this Manual shall be considered to be in the public domain."

Jonas

[mswhin63]

I can only vouch for Australia, Page 5 shows that it is a trademark in Australia - http://www.deafnessforum.org.au/images/pdf/Hearing%20Augmentation%20Systems%20Signage%20Guide.pdf

After working in the industry, I know that recently the trademark has been enforced a lot more in Australia due to past mismanagement of the signage. I do know though that UK Standards are different in relation to the symbol, although I do not know if it is trademarked. I only assume that it is in some way as the standard we use here are derived from standards used in Europe. If I was living in the UK, I would check it first.

I do not represent the Audio section products any more but just advising of the situation