Current drain of typical electret mic?

[Sandi]

What is the current drain of a small electret mic similar to this:

http://www.maplin.co.uk/images/full/27416i0.jpg

Am thinking of the sort which takes an internal silver oxide battery
and is mono.


Would a mic like this draw a current when it is not plugged in and
not being used?

 

[Robert Baer]

Sandi wrote:

What is the current drain of a small electret mic similar to this:

http://www.maplin.co.uk/images/full/27416i0.jpg

Am thinking of the sort which takes an internal silver oxide battery
and is mono.


Would a mic like this draw a current when it is not plugged in and
not being used?
I do not know of any that use a battery inside; all of those i have

seen get power from the instrument (like the stereo mike input on a
computer - one side is sound and the other side is the power).
In any case,the power is in series from source to mike - meaning if
the mike is disconnected, no current would flow.

 

[Palindr☝me]

Robert Baer wrote:

Sandi wrote:

What is the current drain of a small electret mic similar to this:

http://www.maplin.co.uk/images/full/27416i0.jpg

Am thinking of the sort which takes an internal silver oxide battery
and is mono.


Would a mic like this draw a current when it is not plugged in and not
being used?

I do not know of any that use a battery inside; all of those i have
seen get power from the instrument (like the stereo mike input on a
computer - one side is sound and the other side is the power).
In any case,the power is in series from source to mike - meaning if
the mike is disconnected, no current would flow.

Here is one with a battery inside:
http://www.maplin.co.uk/Module.aspx?ModuleNo=27416&criteria=electret%20&doy=23m2

Individual designs vary - those that take power from the line clearly do
not do so when disconnected. Those with internal batteries typically do
take power whenever switched on. A standard, capacitor-coupled amplifier
input would not provide a path for the DC power.

Some amplifiers have internal links to provide power for electret
microphones, over the microphone lead. Many do not.

--
Sue

 

[Setanta]

"Palindr?me" <me9@privacy.net> wrote in message
news:11vr2ei6snevged@corp.supernews.com...

Robert Baer wrote:
Sandi wrote:

What is the current drain of a small electret mic similar to this:

http://www.maplin.co.uk/images/full/27416i0.jpg

Am thinking of the sort which takes an internal silver oxide battery
and is mono.


Would a mic like this draw a current when it is not plugged in and not
being used?

I do not know of any that use a battery inside; all of those i have
seen get power from the instrument (like the stereo mike input on a
computer - one side is sound and the other side is the power).
In any case,the power is in series from source to mike - meaning if
the mike is disconnected, no current would flow.

Here is one with a battery inside:

http://www.maplin.co.uk/Module.aspx?ModuleNo=27416&criteria=electret%20&doy=

23m2

Individual designs vary - those that take power from the line clearly do
not do so when disconnected. Those with internal batteries typically do
take power whenever switched on. A standard, capacitor-coupled amplifier
input would not provide a path for the DC power.

Some amplifiers have internal links to provide power for electret
microphones, over the microphone lead. Many do not.

--
Sue

electrets should not draw any power when not plugged in

Phantom power is a 48v signal from your desk

 

[TimPerry]

What is the current drain of a small electret mic similar to this:

http://www.maplin.co.uk/images/full/27416i0.jpg

Am thinking of the sort which takes an internal silver oxide battery
and is mono.


Would a mic like this draw a current when it is not plugged in and
not
being used?

I do not know of any that use a battery inside; all of those i have
seen get power from the instrument (like the stereo mike input on a
computer - one side is sound and the other side is the power).
In any case,the power is in series from source to mike - meaning if
the mike is disconnected, no current would flow.

Here is one with a battery inside:


http://www.maplin.co.uk/Module.aspx?ModuleNo=27416&criteria=electret%20&doy=
23m2

Individual designs vary - those that take power from the line clearly do
not do so when disconnected. Those with internal batteries typically do
take power whenever switched on. A standard, capacitor-coupled amplifier
input would not provide a path for the DC power.

Some amplifiers have internal links to provide power for electret
microphones, over the microphone lead. Many do not.

--
Sue



electrets should not draw any power when not plugged in

you are perhaps thinking of computer or camcorder type mics which get
operating voltage from the device they are plugged into. there are many
types that do require a battery or some other voltage supply.

 

[Zak]

Sandi wrote:

What is the current drain of a small electret mic similar to
this:

http://www.maplin.co.uk/images/full/27416i0.jpg

Am thinking of the sort which takes an internal silver oxide
battery and is mono.


Would a mic like this draw a current when it is not plugged in
and not being used?

On 23 Feb 2006, Robert Baer wrote:

I do not know of any that use a battery inside; all of those
i have
seen get power from the instrument (like the stereo mike input
on a computer - one side is sound and the other side is the
power).

You are referring to mics with Plug-In-Power or those with
phantom-power. Other mics have the battery inside.

In any case,the power is in series from source to mike -
meaning if the mike is disconnected, no current would flow.

 

[bob mcree]

Zak wrote:

Sandi wrote:


What is the current drain of a small electret mic similar to
this:

http://www.maplin.co.uk/images/full/27416i0.jpg

Am thinking of the sort which takes an internal silver oxide
battery and is mono.


Would a mic like this draw a current when it is not plugged in
and not being used?



On 23 Feb 2006, Robert Baer wrote:

I do not know of any that use a battery inside; all of those
i have
seen get power from the instrument (like the stereo mike input
on a computer - one side is sound and the other side is the
power).



You are referring to mics with Plug-In-Power or those with
phantom-power. Other mics have the battery inside.



In any case,the power is in series from source to mike -
meaning if the mike is disconnected, no current would flow.



the batteries in a typical electret mike usually last several

years. the draw is so low it is the shelf life of the batteries
that matters. they self-discharge internally with time.

-bob