So I think I actually invented something today

mshilarious

mshilarious

Banned
I mean even maybe patentable, so I went off to do the patent search. There is one guy with a pending app for a similar solution to the problem, but his idea is mechanical and stupid whereas mine is electrical and brilliant :D

But that's not what this post is about, it's about all of the other stupid patents & applications I read through doing the search. I mean, take this poor slob:

http://www.freepatentsonline.com/20080019540.pdf

The "invention" there is the pot that acts as a load on the mic. There is nothing remotely novel about it, and besides it's a crap solution to the problem, if reduction of distortion is the object as well as simple attenuation.

USPTO should provide a box for comments on pending applications so we can heckle stuff like that :rolleyes:
 
Well I've given up on actually building my idea so I'll make it public domain: a combined USB/phantom powered mic that only has the standard 3-pin XLR connector (there is an application that has separate mechanical connectors in a single shaft, but requires a special adaptor plug to use USB, and does not describe the circuit whatsoever--presumably totally separate A & D outputs). The twist is pin 1 is not hardwired to ground inside the mic, but the chassis is. Therefore, the USB connection is:

1: Vbus
2: D+
3: D-
chassis: ground

There are CMOS transmission gates on pins 2 and 3 that are switched using pin 1 logic. This keeps the USB transceiver from exploding when the mic is connected to phantom power, and the USB data lines from getting screwed with the audio signal. There would be other circuit protection schemes that are prior art and thus not part of the invention.

The front end circuit could be any type of required microphone, although a dynamic mic would have to have an onboard amplifier to make it through the gates without too much degradation, and phantom power would have to be present to operate the gates anyway.

The USB cable would be a custom USB-->XLR jobby, but the mic cable for phantom power can be any standard mic cable, with the caveat that pin 1 must be wired to chassis (all of mine are anyway, it's a good idea).

Et voila, you have a microphone that is either a standard phantom-powered analog mic or a USB mic, depending on the cable connected.

The advantage to the end-user over mechanical boy's application is that the custom adaptor plug is not required, and it's simple for anyone who can solder to quickly fab the USB-->XLR cable by hacking the end off of a standard USB cable.

Of course in a LDC you have space for totally separate connectors, but I like very very small things, so . . .

There was also a bit about sending a second mic's signal into the USB mic, riding on the USB signal AM-radio style (taking advantage of the differential nature of USB by injecting a common-mode AF signal and demodulating via summing, heh), such that the USB output would be stereo rather than mono. That is a huge weakness of USB mic implementations, because the transceiver ICs are stereo. But I decided I'd had enough, so I stopped there :o That would be pretty complicated and I'm not sure it would work too well anyway, probably be really noisy . . .
 
mshilarious said:
Well I've given up on actually building my idea so I'll make it public domain: a combined USB/phantom powered mic that only has the standard 3-pin XLR connector (there is an application that has separate mechanical connectors in a single shaft, but requires a special adaptor plug to use USB, and does not describe the circuit whatsoever--presumably totally separate A & D outputs). The twist is pin 1 is not hardwired to ground inside the mic, but the chassis is. Therefore, the USB connection is:

1: Vbus
2: D+
3: D-
chassis: ground

There are CMOS transmission gates on pins 2 and 3 that are switched using pin 1 logic. This keeps the USB transceiver from exploding when the mic is connected to phantom power, and the USB data lines from getting screwed with the audio signal. There would be other circuit protection schemes that are prior art and thus not part of the invention.

The front end circuit could be any type of required microphone, although a dynamic mic would have to have an onboard amplifier to make it through the gates without too much degradation, and phantom power would have to be present to operate the gates anyway.

The USB cable would be a custom USB-->XLR jobby, but the mic cable for phantom power can be any standard mic cable, with the caveat that pin 1 must be wired to chassis (all of mine are anyway, it's a good idea).

Et voila, you have a microphone that is either a standard phantom-powered analog mic or a USB mic, depending on the cable connected.

The advantage to the end-user over mechanical boy's application is that the custom adaptor plug is not required, and it's simple for anyone who can solder to quickly fab the USB-->XLR cable by hacking the end off of a standard USB cable.

Of course in a LDC you have space for totally separate connectors, but I like very very small things, so . . .

There was also a bit about sending a second mic's signal into the USB mic, riding on the USB signal AM-radio style (taking advantage of the differential nature of USB by injecting a common-mode AF signal and demodulating via summing, heh), such that the USB output would be stereo rather than mono. That is a huge weakness of USB mic implementations, because the transceiver ICs are stereo. But I decided I'd had enough, so I stopped there :o That would be pretty complicated and I'm not sure it would work too well anyway, probably be really noisy . . .
Click to expand...

I just thought of that like 5 minutes before you posted that...
 
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