370FXP

Power Transformers Overview

The Hammond Manufacturing 370FXP is a potted power transformer belonging to the 300P Series, designed for high voltage and filament applications. It features a universal primary winding compatible with input voltages ranging from 100 VAC to 240 VAC at 50/60 Hz. The unit delivers a rated power of 141 VA. The secondary configuration provides a 550 VAC center-tapped output at 173 mA, supplemented by a 50 VAC bias tap derived from the high voltage secondary. The transformer is enclosed in a drawn steel case and completely potted in epoxy to minimize stray fields and noise.

Power Transformers Feature Summary

• Encased in a drawn steel housing with complete epoxy potting for structural integrity and noise reduction.
• Features concentric windings to achieve low stray electromagnetic fields and operational quietness.
• Includes a dedicated 50 VAC bias tap extracted from the high voltage secondary center tap.
• Finished with black powder paint to coordinate visually with other components in the series.

Power Transformers Applications

• High voltage plate supply circuits in audio equipment
• Filament heating requirements for vacuum tubes
• Industrial control transformer installations requiring isolation
• Replacement units for classic tube amplifier designs

Power Transformers Procurement Notes

Verify that the specific application requires the potted 300P Series construction rather than the open-frame 300 Series alternatives. Confirm that the universal primary voltage range aligns with the local mains supply standards. Ensure the physical dimensions of the steel enclosure fit within the designated chassis space. Check that the epoxy potting does not interfere with adjacent thermal management requirements or mounting hardware constraints during installation.

Power Transformers Selection Notes

Select this model when environmental sealing and noise suppression are critical priorities over cost efficiency. The potted design offers superior protection against moisture and vibration compared to open-frame variants. Consider the weight implications of the steel enclosure and epoxy filling for portable applications. Evaluate the need for the specific 50 VAC bias tap; if unnecessary, an open-frame alternative may provide a more economical solution without compromising electrical performance.

Power Transformers Part Context

This component is part of the Hammond 300P Series, which specializes in potted power transformers. The series is engineered to match aesthetically and functionally with Hammond's potted output transformers and chokes. The black powder finish ensures visual consistency across assembled systems. This specific model represents a mid-range power option within the lineup, balancing size and output capacity for standard industrial and audio applications.

Power Transformers Replacement Considerations

The open-frame 370FX serves as a direct electrical substitute but lacks the epoxy potting and steel enclosure. Verify that the absence of potting in the replacement does not violate safety or noise regulations. Ensure the mechanical mounting holes and lead wire lengths remain compatible with the existing assembly layout before proceeding with substitution.