connecting panasonic mic to icp p/s

[mkoijn]

Hello,

I have some panasonic microphone capsules (output impedance 2k) that should run on a 10 volt 0.5 mA pantom power supply, how could I use the ICP power supply that I already have, to power the microphone capsules? The ICP power supply is 24 volt, 4 mA constant current. It is designed for devices with about 200 ohm output impedance. any help will be appreciated.

Thanks

Al

 

[itsmoked]

You would need to build a linear voltage regulation system to drop the 24V down to 10V. (not very difficult for your power requirements.

Google for "linear regulators and LM317".

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[mkoijn]

Thanks,

Perhaps I explained very badly, The ICP power supply, besides supplying the power to sensors also recieves the signal from the sensor and amplifies it to line level. would your suggestion of building a linear regulator still work in this case?

Al

 

[itsmoked]

I am struggling with what a "pantom" power supply?
And what an ICP power supply is.

You can always regulate some part or a higher voltage supply to run some sub componentry.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[mkoijn]

Sorry it was a typo in my first post, I meant "Phantom power"

Here is an introduction to ICP power supplies. If you would have a look, I would be very grateful.

http://www.pcb.com/techsupport/tech_signal.php

Thanks again

Al

 

[itsmoked]

Well I looked... You are not giving me a lot (I need) to go on. So you need to take my answers with a grain of salt. Or give me a bunch more detailed info.

Assumptions:
1) Your "ICP" supply is a 4mA current source with a 24V compliance.

2) You want a 10V voltage source that can supply 500uA.

Solution: You can use an LM317,(and a few other components), set to output 10V from 24V input. As long as your regulator and microphone system do not draw more than 4mA there should be no problems.

If you are talking about using other aspects of the ICP supply for monitoring the microphones(other than just using the power), I have no clue. You will just have to ask the microphone maker or try it.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[bklauba]

This link might help explain things:

http://www.tangible-technology.com/power/Phantom_Power_connect.html

These work much like the power supplies used with typical accelerometers: An open circuit voltage of say 24 VDC, with constant current of 3 mA (pretty typical specs for standard industrial accelerometers), will drop to say, 12 - 14 VDC when the sensor is connected. The voltage drop defines the max P-P voltage that can then travel, i.e, be superimposed on the same line carrying the "phantom power". At the power supply, a suitable non-polarized cap will take the AC component of the superimposed signal, and send it on its merry way to the preamp/board or whatever.

Linguistically, the term "phantom power" came about due (I believe) from there being an absence of any batteries, nor a distinguishable-from-the-preamp circuit to power the mic, hence phantom.

BK

 

[bklauba]

After you regulate down to the VDC you need, you might find that an LM334 to be useful, for your constant current circuit. We use these in our accelerometer amps, and have found them to work well.

BK