The plates, which enclose a gas, are subjected to a polarizing voltage.
2.
On a dual coil device, when polarized voltage is applied to the reset coil the contacts will transition.
3.
Condenser microphones have impedance converter ( current amplifier ) circuitry that requires powering; in addition, the capsule of any non-electret, non-RF condenser microphone requires a polarizing voltage to be applied.
4.
Unlike other condenser microphones, electret types require no polarizing voltage, but they normally contain an integrated preamplifier, which does require a small amount of power ( often incorrectly called polarizing power or bias ).
5.
Personal computer sound cards, such as Creative Labs'Sound Blaster line use a 3.5 mm phone connector as a mono microphone input, and deliver a 5 V polarizing voltage on the ring to power electret microphones.
6.
Sometimes termed " phantom power ", this is not a suitable power source for microphones designed for true phantom power and is better termed " bias voltage " . ( Note that this is not a polarizing voltage for the condenser, as electrets by definition have an intrinsic voltage; it is power for a FET preamplifier built into the microphone . ) Compatibility between different manufacturers is unreliable.