Typical applications and use
- Power supply for CCP transducers and preamplifiers
- General-purposes measurements
- Precision measurements
- Wide-band measurements
- Switchable A-weighting network
- Low noise
- Battery operated
This low-noise single-channel power supply applies to e.g.:
- ½-inch Preamplifier 26CA
- ¼-inch Preamplifier 26CB
- Array Microphones 40PR and Type 40PQ
- Probe Microphone 40SC
The 12AL can also be used with similar products from other manufacturers.
The 12AL will supply a transducer with a constant current of 4 mA. It has a wide operating frequency range from about 1 Hz (depending on load impedance) to well over 200 kHz. It also has an A-weighting filter which can be switched in or out.
The 12AL can be powered either by two internal AA alkaline batteries or from an external DC supply of 3 - 6 V. A regulated mains/line adapter AB0005 is available for supplying external DC power.
LEDs are used to indicate battery condition; green for power OK and red for battery low. Another red LED is used to indicate cable break, short circuit and overload.
The 12AL has zero gain since the output signal from the transducer is wired directly via 22 μF to the output connector. Zero gain is also preserved at 1 kHz when the A-weighting network has been switched in.
The size and weight of the 12AL make it a compact and handy power supply for CCP transducers both in the laboratory and in the field.
|Frequency response (±3.0 dB) (with 10 kΩ load)||Hz||0.7 to 200 k|
|Frequency response (±3.0 dB) (with 100 kΩ load)||Hz||0.07 to 200 k|
|Output impedance, with A-weighting||Ω||100 in serial with 22µF|
|Output impedance, without A-weighting||Ω||As source in serial with 22µF|
|Inherent noise, A-filter "on" and with dummy microphone (20 Hz to 20 kHz),||µVrms||15|
|Inherent noise, A-filter "off" and with dummy microphone (20 Hz to 20 kHz),||µVrms||4|
|A-weighting filter according to||IEC 61651 Type 0|
|Type||Constant Current Power (CCP)|
|Input channel, CCP||1|
|Input channel(s), traditional power supply||1|
|CCP preamplifier supply @ +28 V||mA||4|
|Power supply, battery||2 x LR6 (AA)|
|Power supply, external||Vdc||3 to 6|
|Power consumption||mA||50 to 120|
|Weight||g / oz||110.00 / 3.88|
|Weight with batteries||g / oz||160 / 5,6|
|G.R.A.S. AB0005||Mains/line adapter|