Electret mic wiring...

A

asdf@mindsf.com

Guest
Hi all,

I have some electret mics that were bestowed upon me, yet they don't have
any identifying marks on them. They have three pads on them - 2 small ones
that are the same size, and a larger one. I have tried to find out how to
identify them, but to no avail. I understand that one is a supply, one is a
ground and the other is the signal line. I just don't know which is which.
Can anyone tell me a way to "ring" this out?

Thank you for your time.

Scott
 
Me again,

I discovered that one of the small pads is ground. I can see a trace coming
off of it to the case. That leaves the other small pad and the large one.
Just to give a visual, the pad arrangement looks like a Jack-O-Lantern face
when you look at it. The eyes being the small pads and the mouth the large
one. Any ideas on how I can identify the othe two pads?

Thanks again,

Scott
 
"asdf@mindsf.com" <sdlf.dfsdsaf.com> wrote in message
news:nvGdnZ_laJ4kZKnXnZ2dnUVZ_rOdnZ2d@earthlink.com...
Hi all,

I have some electret mics that were bestowed upon me, yet they don't have
any identifying marks on them. They have three pads on them - 2 small ones
that are the same size, and a larger one. I have tried to find out how to
identify them, but to no avail. I understand that one is a supply, one is
a ground and the other is the signal line. I just don't know which is
which. Can anyone tell me a way to "ring" this out?

Thank you for your time.

Scott

Are there any color markings on/near the dots?
Click to expand...
Tom
 
"Tom Biasi" <tombiasi@optonline.net> wrote in message
news:4a352313$0$22508$607ed4bc@cv.net...
"asdf@mindsf.com" <sdlf.dfsdsaf.com> wrote in message
news:nvGdnZ_laJ4kZKnXnZ2dnUVZ_rOdnZ2d@earthlink.com...
Hi all,

I have some electret mics that were bestowed upon me, yet they don't have
any identifying marks on them. They have three pads on them - 2 small
ones that are the same size, and a larger one. I have tried to find out
how to identify them, but to no avail. I understand that one is a supply,
one is a ground and the other is the signal line. I just don't know which
is which. Can anyone tell me a way to "ring" this out?

Thank you for your time.

Scott

Are there any color markings on/near the dots?
Tom
Click to expand...
Tom,

I'm afraid not. There's not a mark to be seen on 'em. I've got about 15 of
these, so I figure I could always do it trial by fire (hopefully, not
literally).

Scott
 
"Scott Brehler" <sbrehler@mindspring.com> wrote in message
news:l8WdnVRDDYMN2ajXnZ2dnUVZ_rednZ2d@earthlink.com...
"Tom Biasi" <tombiasi@optonline.net> wrote in message
news:4a352313$0$22508$607ed4bc@cv.net...

"asdf@mindsf.com" <sdlf.dfsdsaf.com> wrote in message
news:nvGdnZ_laJ4kZKnXnZ2dnUVZ_rOdnZ2d@earthlink.com...
Hi all,

I have some electret mics that were bestowed upon me, yet they don't
have any identifying marks on them. They have three pads on them - 2
small ones that are the same size, and a larger one. I have tried to
find out how to identify them, but to no avail. I understand that one is
a supply, one is a ground and the other is the signal line. I just don't
know which is which. Can anyone tell me a way to "ring" this out?

Thank you for your time.

Scott

Are there any color markings on/near the dots?
Tom


Tom,

I'm afraid not. There's not a mark to be seen on 'em. I've got about 15 of
these, so I figure I could always do it trial by fire (hopefully, not
literally).

Scott
Click to expand...
Well if you don't mind a sacrefice or two, connect +3 volts to one dot and
the negative to the one that you ID as common. Feed the other dot into an
amp and see what happens.

Tom
 
"Tom Biasi" <tombiasi@optonline.net> wrote in message
news:4a354da2$0$5917$607ed4bc@cv.net...
"Scott Brehler" <sbrehler@mindspring.com> wrote in message
news:l8WdnVRDDYMN2ajXnZ2dnUVZ_rednZ2d@earthlink.com...

"Tom Biasi" <tombiasi@optonline.net> wrote in message
news:4a352313$0$22508$607ed4bc@cv.net...

"asdf@mindsf.com" <sdlf.dfsdsaf.com> wrote in message
news:nvGdnZ_laJ4kZKnXnZ2dnUVZ_rOdnZ2d@earthlink.com...
Hi all,

I have some electret mics that were bestowed upon me, yet they don't
have any identifying marks on them. They have three pads on them - 2
small ones that are the same size, and a larger one. I have tried to
find out how to identify them, but to no avail. I understand that one
is a supply, one is a ground and the other is the signal line. I just
don't know which is which. Can anyone tell me a way to "ring" this out?

Thank you for your time.

Scott

Are there any color markings on/near the dots?
Tom


Tom,

I'm afraid not. There's not a mark to be seen on 'em. I've got about 15
of these, so I figure I could always do it trial by fire (hopefully, not
literally).

Scott


Well if you don't mind a sacrefice or two, connect +3 volts to one dot and
the negative to the one that you ID as common. Feed the other dot into an
amp and see what happens.

Tom
Click to expand...
Tom,

Thanks. I think that unless someone else comes up with a way to ID these
then that is what I'm going to do. I tried to Ohm out the thing to see if
there is any logical resistance measurments that I could come up with, but I
don't get anything on my DMM in any configuration. Thanks again...


Take care,

Scott
 
Scott Brehler wrote:

"Tom Biasi" <tombiasi@optonline.net> wrote in message
news:4a354da2$0$5917$607ed4bc@cv.net...

"Scott Brehler" <sbrehler@mindspring.com> wrote in message
news:l8WdnVRDDYMN2ajXnZ2dnUVZ_rednZ2d@earthlink.com...

"Tom Biasi" <tombiasi@optonline.net> wrote in message
news:4a352313$0$22508$607ed4bc@cv.net...

"asdf@mindsf.com" <sdlf.dfsdsaf.com> wrote in message
news:nvGdnZ_laJ4kZKnXnZ2dnUVZ_rOdnZ2d@earthlink.com...
Hi all,

I have some electret mics that were bestowed upon me, yet they
don't have any identifying marks on them. They have three pads on
them - 2 small ones that are the same size, and a larger one. I
have tried to find out how to identify them, but to no avail. I
understand that one is a supply, one is a ground and the other is
the signal line. I just don't know which is which. Can anyone tell
me a way to "ring" this out?

Thank you for your time.

Scott

Are there any color markings on/near the dots?
Tom


Tom,

I'm afraid not. There's not a mark to be seen on 'em. I've got about
15 of these, so I figure I could always do it trial by fire
(hopefully, not literally).

Scott


Well if you don't mind a sacrefice or two, connect +3 volts to one
dot and the negative to the one that you ID as common. Feed the other
dot into an amp and see what happens.

Tom

Tom,

Thanks. I think that unless someone else comes up with a way to ID
these then that is what I'm going to do. I tried to Ohm out the thing
to see if there is any logical resistance measurments that I could
come up with, but I don't get anything on my DMM in any configuration.
Thanks again...


Take care,

Scott
http://en.wikipedia.org/wiki/Electret_microphone
Click to expand...
--
Best Regards:
Baron.
 
"Baron" <baron.nospam@linuxmaniac.nospam.net> wrote in message
news:h13ob8$lq$1@news.eternal-september.org...
Scott Brehler wrote:


"Tom Biasi" <tombiasi@optonline.net> wrote in message
news:4a354da2$0$5917$607ed4bc@cv.net...

"Scott Brehler" <sbrehler@mindspring.com> wrote in message
news:l8WdnVRDDYMN2ajXnZ2dnUVZ_rednZ2d@earthlink.com...

"Tom Biasi" <tombiasi@optonline.net> wrote in message
news:4a352313$0$22508$607ed4bc@cv.net...

"asdf@mindsf.com" <sdlf.dfsdsaf.com> wrote in message
news:nvGdnZ_laJ4kZKnXnZ2dnUVZ_rOdnZ2d@earthlink.com...
Hi all,

I have some electret mics that were bestowed upon me, yet they
don't have any identifying marks on them. They have three pads on
them - 2 small ones that are the same size, and a larger one. I
have tried to find out how to identify them, but to no avail. I
understand that one is a supply, one is a ground and the other is
the signal line. I just don't know which is which. Can anyone tell
me a way to "ring" this out?

Thank you for your time.

Scott

Are there any color markings on/near the dots?
Tom


Tom,

I'm afraid not. There's not a mark to be seen on 'em. I've got about
15 of these, so I figure I could always do it trial by fire
(hopefully, not literally).

Scott


Well if you don't mind a sacrefice or two, connect +3 volts to one
dot and the negative to the one that you ID as common. Feed the other
dot into an amp and see what happens.

Tom

Tom,

Thanks. I think that unless someone else comes up with a way to ID
these then that is what I'm going to do. I tried to Ohm out the thing
to see if there is any logical resistance measurments that I could
come up with, but I don't get anything on my DMM in any configuration.
Thanks again...


Take care,

Scott
http://en.wikipedia.org/wiki/Electret_microphone
--
Best Regards:
Baron.
Click to expand...
Baron,

Thanks Baron. Yes, I was there -I usually check out Wiki first thing. But it
didn't tell me anything about how to identify the leads. At least nothing
that I could tell from the schematics, etc. I'm not a professional tech or
anything (although, I do feel that I'm not an amature), so if you can tell
me how to tell from the schematics how to identify the leads that would be
great. I.E resistance measurments that identify bias of the FET or the like.

Sincerely,
Scott
 
Scott Brehler wrote:
"Baron" <baron.nospam@linuxmaniac.nospam.net> wrote in message
news:h13ob8$lq$1@news.eternal-september.org...

Scott Brehler wrote:


"Tom Biasi" <tombiasi@optonline.net> wrote in message
news:4a354da2$0$5917$607ed4bc@cv.net...

"Scott Brehler" <sbrehler@mindspring.com> wrote in message
news:l8WdnVRDDYMN2ajXnZ2dnUVZ_rednZ2d@earthlink.com...

"Tom Biasi" <tombiasi@optonline.net> wrote in message
news:4a352313$0$22508$607ed4bc@cv.net...

"asdf@mindsf.com" <sdlf.dfsdsaf.com> wrote in message
news:nvGdnZ_laJ4kZKnXnZ2dnUVZ_rOdnZ2d@earthlink.com...

Hi all,

I have some electret mics that were bestowed upon me, yet they
don't have any identifying marks on them. They have three pads on
them - 2 small ones that are the same size, and a larger one. I
have tried to find out how to identify them, but to no avail. I
understand that one is a supply, one is a ground and the other is
the signal line. I just don't know which is which. Can anyone tell
me a way to "ring" this out?

Thank you for your time.

Scott


Are there any color markings on/near the dots?
Tom


Tom,

I'm afraid not. There's not a mark to be seen on 'em. I've got about
15 of these, so I figure I could always do it trial by fire
(hopefully, not literally).

Scott


Well if you don't mind a sacrefice or two, connect +3 volts to one
dot and the negative to the one that you ID as common. Feed the other
dot into an amp and see what happens.

Tom

Tom,

Thanks. I think that unless someone else comes up with a way to ID
these then that is what I'm going to do. I tried to Ohm out the thing
to see if there is any logical resistance measurments that I could
come up with, but I don't get anything on my DMM in any configuration.
Thanks again...


Take care,

Scott

http://en.wikipedia.org/wiki/Electret_microphone
--
Best Regards:
Baron.


Baron,

Thanks Baron. Yes, I was there -I usually check out Wiki first thing. But it
didn't tell me anything about how to identify the leads. At least nothing
that I could tell from the schematics, etc. I'm not a professional tech or
anything (although, I do feel that I'm not an amature), so if you can tell
me how to tell from the schematics how to identify the leads that would be
great. I.E resistance measurments that identify bias of the FET or the like.

Sincerely,
Scott


use a 1200 ohm or near that in series with the supply line. connect the
Click to expand...
other end of the R to one of the small legs, and the remaining small leg
to the (-) side of a low voltage supply.
Take a scope reading at the pad that the R is connected to referenced
from the common (-) side of the supply.
If it does not appear to be out put anything, switch the leads..

These mic's need a series R from the supply. The case is just a ground
and does not necessarily connect to the (-) terminal supply at some point.

Most mic's of this type are 2 wire.
 
"Jamie" <jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote in message
news:HafZl.7208$7C4.407@newsfe04.iad...
Scott Brehler wrote:
"Baron" <baron.nospam@linuxmaniac.nospam.net> wrote in message
news:h13ob8$lq$1@news.eternal-september.org...

Scott Brehler wrote:


"Tom Biasi" <tombiasi@optonline.net> wrote in message
news:4a354da2$0$5917$607ed4bc@cv.net...

"Scott Brehler" <sbrehler@mindspring.com> wrote in message
news:l8WdnVRDDYMN2ajXnZ2dnUVZ_rednZ2d@earthlink.com...

"Tom Biasi" <tombiasi@optonline.net> wrote in message
news:4a352313$0$22508$607ed4bc@cv.net...

"asdf@mindsf.com" <sdlf.dfsdsaf.com> wrote in message
news:nvGdnZ_laJ4kZKnXnZ2dnUVZ_rOdnZ2d@earthlink.com...

Hi all,

I have some electret mics that were bestowed upon me, yet they
don't have any identifying marks on them. They have three pads on
them - 2 small ones that are the same size, and a larger one. I
have tried to find out how to identify them, but to no avail. I
understand that one is a supply, one is a ground and the other is
the signal line. I just don't know which is which. Can anyone tell
me a way to "ring" this out?

Thank you for your time.

Scott


Are there any color markings on/near the dots?
Tom


Tom,

I'm afraid not. There's not a mark to be seen on 'em. I've got about
15 of these, so I figure I could always do it trial by fire
(hopefully, not literally).

Scott


Well if you don't mind a sacrefice or two, connect +3 volts to one
dot and the negative to the one that you ID as common. Feed the other
dot into an amp and see what happens.

Tom

Tom,

Thanks. I think that unless someone else comes up with a way to ID
these then that is what I'm going to do. I tried to Ohm out the thing
to see if there is any logical resistance measurments that I could
come up with, but I don't get anything on my DMM in any configuration.
Thanks again...


Take care,

Scott

http://en.wikipedia.org/wiki/Electret_microphone
--
Best Regards:
Baron.


Baron,

Thanks Baron. Yes, I was there -I usually check out Wiki first thing. But
it didn't tell me anything about how to identify the leads. At least
nothing that I could tell from the schematics, etc. I'm not a
professional tech or anything (although, I do feel that I'm not an
amature), so if you can tell me how to tell from the schematics how to
identify the leads that would be great. I.E resistance measurments that
identify bias of the FET or the like.

Sincerely,
Scott
use a 1200 ohm or near that in series with the supply line. connect the
other end of the R to one of the small legs, and the remaining small leg
to the (-) side of a low voltage supply.
Take a scope reading at the pad that the R is connected to referenced
from the common (-) side of the supply.
If it does not appear to be out put anything, switch the leads..

These mic's need a series R from the supply. The case is just a ground
and does not necessarily connect to the (-) terminal supply at some point.

Most mic's of this type are 2 wire.
Click to expand...
Jamie,

Thanks for the info. I'll try that tomorrow.

I do have some mics that are two wire, but for some reason these have the
three pads. I got them from a guy who used to be in law enforcement. He
built his own bugs, etc. This was several years ago and I have no idea how
to contact him. I just didn't want to go frying the things trying to figure
'em out. Thank you...

Scott
>
 
On Sun, 14 Jun 2009 20:18:18 -0400, "Scott Brehler" <sbrehler@mindspring.com>
wrote:

:
:"Jamie" <jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote in message
:news:HafZl.7208$7C4.407@newsfe04.iad...
:> Scott Brehler wrote:
:>> "Baron" <baron.nospam@linuxmaniac.nospam.net> wrote in message
:>> news:h13ob8$lq$1@news.eternal-september.org...
:>>
:>>>Scott Brehler wrote:
:>>>
:>>>
:>>>>"Tom Biasi" <tombiasi@optonline.net> wrote in message
:>>>>news:4a354da2$0$5917$607ed4bc@cv.net...
:>>>>
:>>>>>"Scott Brehler" <sbrehler@mindspring.com> wrote in message
:>>>>>news:l8WdnVRDDYMN2ajXnZ2dnUVZ_rednZ2d@earthlink.com...
:>>>>>
:>>>>>>"Tom Biasi" <tombiasi@optonline.net> wrote in message
:>>>>>>news:4a352313$0$22508$607ed4bc@cv.net...
:>>>>>>
:>>>>>>>"asdf@mindsf.com" <sdlf.dfsdsaf.com> wrote in message
:>>>>>>>news:nvGdnZ_laJ4kZKnXnZ2dnUVZ_rOdnZ2d@earthlink.com...
:>>>>>>>
:>>>>>>>>Hi all,
:>>>>>>>>
:>>>>>>>>I have some electret mics that were bestowed upon me, yet they
:>>>>>>>>don't have any identifying marks on them. They have three pads on
:>>>>>>>>them - 2 small ones that are the same size, and a larger one. I
:>>>>>>>>have tried to find out how to identify them, but to no avail. I
:>>>>>>>>understand that one is a supply, one is a ground and the other is
:>>>>>>>>the signal line. I just don't know which is which. Can anyone tell
:>>>>>>>>me a way to "ring" this out?
:>>>>>>>>
:>>>>>>>>Thank you for your time.
:>>>>>>>>
:>>>>>>>>Scott
:>>>>>>>>
:>>>>>>>
:>>>>>>>Are there any color markings on/near the dots?
:>>>>>>>Tom
:>>>>>>>
:>>>>>>
:>>>>>>Tom,
:>>>>>>
:>>>>>>I'm afraid not. There's not a mark to be seen on 'em. I've got about
:>>>>>>15 of these, so I figure I could always do it trial by fire
:>>>>>>(hopefully, not literally).
:>>>>>>
:>>>>>>Scott
:>>>>>>
:>>>>>
:>>>>>Well if you don't mind a sacrefice or two, connect +3 volts to one
:>>>>>dot and the negative to the one that you ID as common. Feed the other
:>>>>>dot into an amp and see what happens.
:>>>>>
:>>>>>Tom
:>>>>
:>>>>Tom,
:>>>>
:>>>>Thanks. I think that unless someone else comes up with a way to ID
:>>>>these then that is what I'm going to do. I tried to Ohm out the thing
:>>>>to see if there is any logical resistance measurments that I could
:>>>>come up with, but I don't get anything on my DMM in any configuration.
:>>>>Thanks again...
:>>>>
:>>>>
:>>>>Take care,
:>>>>
:>>>>Scott
:>>>
:>>>http://en.wikipedia.org/wiki/Electret_microphone
:>>>--
:>>>Best Regards:
:>>> Baron.
:>>
:>>
:>> Baron,
:>>
:>> Thanks Baron. Yes, I was there -I usually check out Wiki first thing. But
:>> it didn't tell me anything about how to identify the leads. At least
:>> nothing that I could tell from the schematics, etc. I'm not a
:>> professional tech or anything (although, I do feel that I'm not an
:>> amature), so if you can tell me how to tell from the schematics how to
:>> identify the leads that would be great. I.E resistance measurments that
:>> identify bias of the FET or the like.
:>>
:>> Sincerely,
:>> Scott
:> use a 1200 ohm or near that in series with the supply line. connect the
:> other end of the R to one of the small legs, and the remaining small leg
:> to the (-) side of a low voltage supply.
:> Take a scope reading at the pad that the R is connected to referenced
:> from the common (-) side of the supply.
:> If it does not appear to be out put anything, switch the leads..
:>
:> These mic's need a series R from the supply. The case is just a ground
:> and does not necessarily connect to the (-) terminal supply at some point.
:>
:> Most mic's of this type are 2 wire.
:
:Jamie,
:
:Thanks for the info. I'll try that tomorrow.
:
:I do have some mics that are two wire, but for some reason these have the
:three pads. I got them from a guy who used to be in law enforcement. He
:built his own bugs, etc. This was several years ago and I have no idea how
:to contact him. I just didn't want to go frying the things trying to figure
:'em out. Thank you...
:
:Scott
:>
:


The case will be GND so that leaves you a 50:50 chance of guessing the battery
feed terminal correctly. If you connect to 1.5V battery using a 1kohm resistor
you can avoid blowing it up even if you get it wrong the first time.

Read Rod Elliot's page on an electret project and see Fig 8 which depicts a 3
terminal Panasonic mic.
http://sound.westhost.com/project93.htm
 
:
:The case will be GND so that leaves you a 50:50 chance of guessing the battery
:feed terminal correctly. If you connect to 1.5V battery using a 1kohm resistor
:you can avoid blowing it up even if you get it wrong the first time.
:
:Read Rod Elliot's page on an electret project and see Fig 8 which depicts a 3
:terminal Panasonic mic.
:http://sound.westhost.com/project93.htm


What I meant was that Fig 8 might help you better understand the terminal
arrangement on the mic capsule. The Panasonic mic is essentially a 2 terminal
element but a simple modification makes it a 3 terminal element.
 
Ross,

Thanks for the info. I was hoping for a way to try this without blowing them
up and still know that they were configured correctly for them to work if I
had it right. Thanks again,

Scott
"Ross Herbert" <rherber1@bigpond.net.au> wrote in message
news:kc7c35pqobbptb4fbmk6h1e2397pl6m7a6@4ax.com...
:
:The case will be GND so that leaves you a 50:50 chance of guessing the
battery
:feed terminal correctly. If you connect to 1.5V battery using a 1kohm
resistor
:you can avoid blowing it up even if you get it wrong the first time.
:
:Read Rod Elliot's page on an electret project and see Fig 8 which depicts
a 3
:terminal Panasonic mic.
:http://sound.westhost.com/project93.htm


What I meant was that Fig 8 might help you better understand the terminal
arrangement on the mic capsule. The Panasonic mic is essentially a 2
terminal
element but a simple modification makes it a 3 terminal element.
Click to expand...
 
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