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ACT-25 Audio Coupling Transformer
Product Installation Document
PN 53432:A 7/07/2008 08-484
This product has been certified to comply with requirements in the Standard for Control Units and accessories for Fire
Alarm Systems, UL 864 9th Edition. Operation of this product with products not tested for UL 864 9th Edition has not
been evaluated. Such operation requires the approval of the local Authority Having Jurisdiction.
Products mentioned in this document that have not received UL 864 9th Edition certification:
• AMG-1
Applications
When used with the high-level output of an AA-30 (driven by a low-level source, such as the AMG-1, RM-1, or DVC-
AO), or with the high-level output of a DAA in riser mode, ACT-25 Audio Coupling Transformers will provide a means
to drive thousands of amplifiers in large audio system applications.
• It attenuates high-level 25V
RMS
to create a low-level audio signal.
• It isolates input from output.
• It provides CMNR (Common Mode Noise Rejection)
The low-level signal created by the ACT-25 may be used to deliver audio to analog amplifiers, as well as to the AUX B
inputs of the DVC and DAA. Refer to the Digital Audio Manual for more DVC and DAA information.
The ACT-25 provides electrical isolation between its input and output and attenuates the signal from high-level audio to
low-level audio. Ground faults on the AUDIO IN input must be detected by the amplifier driving the audio. Ground faults
on the THRU output must be detected by the destination. Ground fault detection for the input and output can be merged
together by using the “COMM” input. Up to 40 analog audio amplifiers may be fed by the output of an ACT-25 as long as
the wiring does not exceed 200 ft (61 m), 18-12 AWG (0.75-3.25 mm
2
).
Figure 1 The ACT-25
Suitable Configurations
Signal from a Digital Audio Amplifier in Riser Mode
The ACT-25 will accept high-level audio signals from any DAA digital audio amplifier with a 25 volt output. It can then
drive a DVC, AA-120/AA-120E, AA-100, and/or AA-30/AA-30E audio amplifiers, as well as the XPIQ-AIB audio input
boards.
ACT-25 Input
P1 Low-level
audio plug pins
ACT-25 Output