I am trying to get some cheap computer headsets to work with a theatre intercom.
The headsets have electret microphones, but the intercom is designed to work with dynamic microphones. The intercom is a "Clearcom" type (manufactured by someone else but very similar)
I have found instructions on how to do this using a 9V battery to power the electret (**broken link removed**) but I am wondering if it possible to use the 48V DC power supply already present in the intercom system (NB it is NOT phantom power, just plain 48VDC).
These are the issues that I need some help with:
1. How do I keep the voltage on the electret under 10V? I haven't been able to find any info on how to select a load resistor value for an arbitrary voltage.
2. If a high value load resistor is used, the output impedance of the mic may be too high to drive the input of the intercom...
3. How to keep the signal level down to a reasonable level?
Thanks in advance
The headsets have electret microphones, but the intercom is designed to work with dynamic microphones. The intercom is a "Clearcom" type (manufactured by someone else but very similar)
I have found instructions on how to do this using a 9V battery to power the electret (**broken link removed**) but I am wondering if it possible to use the 48V DC power supply already present in the intercom system (NB it is NOT phantom power, just plain 48VDC).
These are the issues that I need some help with:
1. How do I keep the voltage on the electret under 10V? I haven't been able to find any info on how to select a load resistor value for an arbitrary voltage.
2. If a high value load resistor is used, the output impedance of the mic may be too high to drive the input of the intercom...
3. How to keep the signal level down to a reasonable level?
Thanks in advance