United Data Corporation

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Telephone Power Supply




48Vdc Power & 20 Hz Ringing Supply

Power Supply

The Proctor Model 42048 II Power Supply provides a convenient, cost-effective source for 48Vdc and 20Hz ringing power for OPX, DID, single-line or general purpose applications. The unit is compact and lightweight and operates wherever standard AC power is available. All power outputs are short-circuit protected. Output connections are made via a screw-down terminal strip inside the unit which is accessed through a rubber grommet on the faceplate. The unit provides user-selectable continuous or interrupted ringing options (strappable). A front panel LED illuminates during overload conditions to indicate the internal electronic circuit breaker has operated. The unit includes an internal user-replaceable fuse.

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How It Works

42048 Schematic

The 42048 Power Supply operates from 115Vac, providing 48Vdc at 1 Amp and 105 VRMS, 20 Hz ringing (continuous or interrupted) at 5 REN. A wiring access grommet on the front panel facilitates customized wiring to the terminals on the internal barrier strip. The 42048 II contains regulating circuitry designed to protect itself against current overloads and excessive temperatures. If a continuous, direct short circuit occurs, and internal electronic circuit breaker will operate and the front panel "Short Circuit Protection" LED will illuminate. The unit is UL Listed and meets FCC Part 68 ringing requirements.

Typical Application

42048 Application

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Key Benefits

    Provides 48 VDC Output (protected) at 1 Amp
    Provides 105 VRMS, 20 Hz ringing at 5 REN.
    Provides continuous or interrupted ringing.
    Operates on common 115 Vac power.
    Short circuit protected; includes LED overload
    indicator on front panel.
    Includes internal user-replaceable fuse.
    Compact and lightweight.
    UL Listed; Meets FCC Ringing Requirements

Model 42048 II Specifications

    • Internal barrier strip
    • Operating Voltage: 115 VAC (nominal), 50 to 60 Hz
    • Input Current: 80 mA
    • Fuse: 2 Amp, 250 Volt, 3AG
    • Output Voltage: -45 to -51 VDC
    • Output Current: 1 Amp
    • Output Voltage: 105V RMS (+/- 20V RMS)(no load)
    • Output Voltage: 65V RMS (minimum) (5 REN load, interrupted)
    • Output Frequency: 21 Hz (+/- 5 Hz) (0 to 5 REN)
    • Interrupted Ringing Cadence: 2 seconds on, 4 seconds off (+/- 15%)
    • Operating Temperature:  0 to 50C (32 to 122 F)
    • Storage Temperature:  -20 to 85C (-4 to 185 F)
    • Humidity: 0% to 95% (Non-Condensing)
    • Dimen: 7.5" (19.05 cm) W x 2.85" (7.23 cm) H
      x 8.5" (21.59 cm) D
    • Wt: 6 lbs (3.17 kg) 



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