[Trevor Wilson[_3_]]

Arny Krueger wrote:
"izms" wrote in message

First and foremost, I am no electrical engineer, a far
cry from it actually. Years ago I assembled a DIY
electret condenser microphone with external power supply
using a 9V battery and loved its performance. I am
curious if there are any power converters small enough to
convert 48V down to 9V or less, that way I could
eliminate the external supply and have the element and
converter in one assembly (like a standard pencil
condenser microphone). The key here is to eliminate the
bulk and keep the microphone as small as possible.

Any ideas would be greatly appreciated. Thanks!

If you want to convert 48 volts to 9, it is a pretty simple problem.

http://hyperphysics.phy-astr.gsu.edu...c/zenereg.html

**A zener regulator may exhibit far too much noise for such an application.
Much better to use a proper low noise regulator, possibly based on a LM317 +
high Voltage pass transistor. Bigger and more complex, but far lower noise
levels. In fact, I've built a few such regulators (for reducing phantom
power to 9 or 12 Volts) and enjoyed great success. Due to the very low
currents, the whole lot can be assembled on a small PCB and contained within
ehat shrink.


--
Trevor Wilson
www.rageaudio.com.au


--
Trevor Wilson
www.rageaudio.com.au