Is there an electret microphone power adapter?

My Canon camcorder has an external mic jack, but the jack provides no power that would allow for using electret mics, which I already have several of. So of course when I plug one of those in, I get no audio. A wireless mic, however, works fine because its receiver is battery powered.

I just assumed I could find a little $2 inline adapter thingy on Ebay that had a coin battery compartment, or maybe two AAAs, and a couple resistors and capacitors, and two 3.5mm stereo jacks, or maybe an input jack and an output plug.

But I have not been able to find anything like that, even at a higher price. So maybe this is not a thing. Has anyone seen anything like this?

If not, I guess I'll make an Altoids version.

Reply to
Peabody
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Hmm I found this,

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from here,
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Searching for Electret mic jack with battery.

Altoids, might be better.

George H.

Reply to
George Herold

This further down the same page of images.

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Reply to
George Herold

I used to use 6-9 volt battery supply. Made my own box. I would get specs on mic.

Greg

Reply to
gregz

Have you checked all the camcorder settings?

For example tucked away in my Tascam pocket recorder setup menu is an option for microphone power expressly for this kind of situation.

piglet

Reply to
piglet

Yes I have, and the camcorder manual is very clear that the mic needs to be one that needs no power. And, just by chance I'm sure, it turns out that Canon makes such mics, both wired and wireless. So while you get an external microphone jack, you really should be using only a Canon mic. Right.

Well, I think I'll just make my own. I found in the junque box an Altoids tin with holes already drilled, and a 9V battery compartment already partitioned off. That has to be an omen that I should make my own. And since my mics only pretend to be stereo, I'll need two jacks, one 10k resistor, one .1 uF capacitor and a 9V battery.

But I'm still a bit surprised that this product doesn't exist on Ebay at a reasonable price.

Thanks for all the replies.

Reply to
Peabody

er

.

An electret is a dielectric with a built-in permanent electric field.

Your microphone is one - moveable - plate of a capacitor on one side of the electret and the other plate is a fixed conducting plate on the other side .

When the moving plate moves, the capacitance of the capacitor changes, and as the voltage imposed across the capaitor by the electret remains the same , a certain amount of charge moves between the plates.

The currents involved don't tend to be large, and it's usual to put an high

-input impedance amplifier close to the two plates, which does need to be p owered, but a simple electret microphone doesn't need a power supply (and w on't drive any signifcant length of capacitative cable - twisted pair, shie lded twisted pair or coax).

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Bill Sloman, Sydney
Reply to
bill.sloman

He's talking about the simple, readily available microphones that come with all manner of cheap electronic devices. They contain a single FET as the "amplifier". It needs power to work.

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Rick C
Reply to
rickman

I was building stuff over 30years ago. I put in attenuator so loud signal would not overload the recorder inputs.

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Greg

Reply to
gregz

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