If I am building a +48V power supply for condenser mics, how stable should the output voltage be? What should my range of error be, as in 48.0 +/- X volts, for solid, functional operation?
2007-08-26 05:46:12 · 2 answers · asked by Not Eddie Money 3 in Science & Mathematics ➔ Engineering
Some phantom power supplies only put out 24 volts, and most microphones work just fine.
There is usually a high valued (~50k to 100k) resistor in series with the phantom supply and the XLR jack which serves to isolate the power supply from the audio, and to limit the current (~5 mA). That is the key -- just make sure there is some voltage greater than 15 volts @ 5 mA, *AT* the microphone (for a condensder type with a normal FET amplifier).
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2007-08-26 08:26:49 · answer #1 · answered by tlbs101 7 · 0⤊ 0⤋
You don't need a extremely precise power supply, since the signal will be taken as a differential voltage. An error of +/- 5% is fine.
2007-08-26 07:31:43 · answer #2 · answered by Kenneth 3 · 0⤊ 0⤋