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M-949-01 Datasheet, PDF (1/3 Pages) Clare, Inc. – Line Sense Relay
Features
• Senses telephone line current from 18 to 125mA
• Includes 1 Form A relay contact
• Maximum closure time 1 ms including bounce
• Achives 63 dB minimum longitudinal balance
• Provides 1500 VDC coil-to-contact isolation
• Improved RFI shielding
• UL Recognized
• Applications include: central office products, PBX
and key systems, rotary dial monitoring devices,
Figure 1 Electrical Configuration
M-949-01
Line Sense Relay
Description
The M-949-01 Line Sense relay is a small PWB-
mount loop current detector with the safety and
reliability features required for FCC Part 68 regulated
telephone applicatoins. When connected to the voice
pair (Tip and Ring of an ordinary telephone line, the
M-949-01 provides a 1 Form A relay closure in
response to current above 20mA flowing hrough the
wires. This closure can be used by control circuitry for
on-hook’off-hook monitoring, switchhook flash
detection, and rotary dial pulse counting. Simple in
design and rugged in construction, the M-949-01 is
ideally suited for use with the Teltone M-959, M-8870,
M-8880, M-8888, and other loop current controlled
telephone dialing recievers.
Ordering Information
Part #
M-949-11
Description
Line Sense Relay
Figure 2 Typical Application: Dialed Digit Monitor
DS-M-949-01-R1.0
www.clare.com
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