9 Volt Phantom Power Circuit

[computerlen]

I have built a phantom power circuit from a wiring diagram I had since 1999. It uses a single 9 volt battery. It works great. I am just wondering if anyone can tell me why it works so well because, as you know, the usual phantom-powered mixing boards have 48 volts. Thanks.

 

[Harald Kapp]

It's because the Elfes added some secret ingredient to the broth before the transistors were hand-forged by the dwarfes to get that singular semi-conductive behaviour.

In all honesty: how do you expect us to give any meaningful answer without knowing the circuit involved? Start by posting the circuit diagram, then we'll see what we can come up with.

 

[computerlen]

I did not have the circuit with me when I posted. I will get it tomorrow from my workplace and show it to you. Besides, my question is simply this: why do you think a 9 volt phantom power circuit powers up a condenser mic when the norm is 48 volts?

 

[AnalogKid]

Your question simply does not have enough information. Are you using a condenser mic, or an electret mic? In terms of their power systems, the two are barely related.

ak

 

[Harald Kapp]

48 V can be generated from 9V.
Also, phantom power comes in different flavors: 12V, 24V and 48V.
Lastly the microphone used may works at a much lower voltage than nominal.

That's why we're awaiting your post of the circuit diagram.

 

[computerlen]

I did not have the circuit with me when I posted. I will get it tomorrow from my workplace and show it to you. Besides, my question is simply this: why do you think a 9 volt phantom power circuit powers up a condenser mic when the norm is 48 volts?

 

[Harald Kapp]

Obviously the mic used works from 9V.

 

[computerlen]

View attachment 27366

Obviously the mic used works from 9V.

I guess you have no idea. I tried it on two mics and they work fine.

 

[Harald Kapp]

I guess you have no idea. I tried it on two mics and they work fine.

That's why I wrote 'Obviously the mic used works from 9V'. If the mic requires a higher voltage, it wouldn't work from 9V. The circuit you showed plainly supplies the mic with 9V only. There is nothing to increase the voltage (as in e.g. a voltage doubler or similar).

 

[AnalogKid]

Again, there are many kinds of microphones. Without knowing what mic you are using, your question has no answer.
What is the manufacturer?
What is the part or model number?
What does the data sheet say is its operating voltage range?

IF the mic is designed to run on 9 V, then the reason it "works great" is that it is designed to run on 9 V.

ak

 

[73's de Edd]

.



Sir computerlen . . . . .

Is post #6 being your units complete schematic, with nothing else connected to the very bottom connector?
Also, by the use of a DMM with its inherent MINIMAL loading, place it in DC mode and tell us what the measured voltage from pin 2-3 on the top connector is.

Seeing that circuitry is configured as a bridge, I have some ideas for up to 36 VDC being available .
But I need to your confirmation of that voltage level initially.
Also double confirm your 47 ufd electrolytic capacitors polarities, that you have shown.

73's de Edd

 

[Harald Kapp]

I have some ideas for up to 36 VDC being available .

I'm waiting to see that . Currently I have no clue how this can be achieved by this simple circuit.

 

[AnalogKid]

As a phantom power inserter, the two 10K resistors are a bit large; but the circuit looks fine to me. If the mic is a standard 2-pin electret element, there needs to be a bit more stuff at the mic end, but that varies based on the characteristics of the mic.

ak