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The 130E20, 130E21, 130E22, 130A23 and 130A24 Microphones (Figure 1) are all Array
Microphones with integral preamplifiers. These Microphones are 7mm in diameter and have a
dynamic range of up to 150dB before clipping occurs, depending on the model. The 130A24 is a
rugged microphone that is water/dust resistant and 13mm in diameter. The 130E20 and 130A24
include a BNC Jack, 130E21 includes a 10-32 Coaxial Jack, and the 130E22 and 130A23 both
include a SMB Coaxial Socket. All 130 series Microphones are Prepolarized. By applying a high
temperature polymer material, which contains frozen electrical charges, to the top of the
backplate, PCB has eliminated the need for external Polarization. This saves you money and
time.
The 130 Series Array Microphones have the following Features:
Lower per Channel Cost
Use ICP
Sensor Power
Prepolarized
Reduce Test Time
Increase Data Consistency
Integrate with Signal Conditioners
Includes TEDS compliant with IEEE
1451.4
With their integrated ICP
preamplifier and Prepolarization, these microphones can be powered
by simple, inexpensive, constant-current Signal Conditioners. These units are easy to operate,
and they interface with many standard signal analysis, data acquisition and recording
instruments. They utilize low-impedance cable on which signals can be driven long distances
with minimal signal loss.
3.0 Powering
All ICP
powered microphones require correct constant-current excitation for proper operation.
For this reason, use only PCB constant-current signal conditioners or other approved constant-
current sources. The signal conditioner consists of a regulated, 18-30 VDC source. The power is
regulated by a current-limiting circuit, which provides the constant current excitation required
for proper operation of the ICP
Microphone. In general, battery powered devices offer
versatility for portable low-noise measurements, whereas line-powered units provide the
capability for continuous monitoring. A typical system schematic is shown in Figure 2.
Figure 2
Certain models of signal conditioners have meters or LEDS, which enable users to monitor the
bias voltage output signal, check microphone operation, and detect cable faults. Normally, a
“yellow” reading indicates an open circuit (example: a cable disconnected); “green” indicates
Note
: Under no circumstances should
a voltage be supplied to an ICP
microphone without a current-
regulating diode or equivalent
electrical circuit. This may include
ohmmeters, multi-meters and
continuity testers. Damage to the
built-in electronics resulting from the
application of incorrect power, or the
use of an unapproved power source, is
NOT covered under warranty.
Microphone
Signal
Conditioner
Readout
