Microphone Power Supply-Type PM2000-S
1. Introduction and Description
The PM2000-S is a dual-channel power supply for preamplifiers used with CCP（constant current power）microphones. It is general use in acoustic measurements and vibration measurements, both in the laboratory and in the Production.
It can provide a constant current for two CCP microphones. It has a wide operating frequency range from about 10Hz to 50kHz. It can provide a high S/N ration and the special low distortion for the input analogue signal.
The Type PM2000-S can be powered by the external AC supply of 220V directly. A series of LEDs are used to indicate the signal condition and power condition; yellow for power OK, green for signal optimum and red for signal overload.
2. External Features
The front panel has the following features:
Preamplifier Input channels: BNC coaxial input connector for microphone preamplifier, including channel A and B
Output channels: BNC coaxial socket for the output signal via the power supply.
Gain switches and Overload LEDs: Adjust the gain of each channel individually to fit requirements and give the overload indication. Gain settings are from 0 dB to +40 dB steps.
LEDs indication: a series LEDs will indicate the different condition, yellow for power OK, green for signal optimum and red for signal overloading.
2 channels (A and B), each comprising:
Input socket: BNC coaxial
Output socket: BNC coaxial
Gain: -10dB, 0dB, 20dB for two channels individually.
Input Impedance: 100kΩ
Output Impedance: less than 30Ω
Transducer supply: Source voltage is 28V and Current is 3mA
Frequency response: 10Hz – 50kHz（±0.5dB）
Channel separation: 20Hz-20kHz over than 60dB
Noise: Less than -100dBV
Power supply: 220V AC
Power OK: yellow
Signal optimum: green