W.U. Tel. Co. PTC 10190-A Prototype Transformer Power Supply For Parts

W.U. Tel. Co. PTC 10190-A Prototype Transformer Power Supply For Parts

The PTC 10190-A is a transformer-based power supply chassis manufactured by Prototype Transformer Corporation (PTC) for W.U. Tel. Co. — Western Union Telephone Company. Built into a sturdy olive-drab open-frame metal chassis, this unit houses two large wound transformer cores, a separate inductor (marked 10244-A), multiple large electrolytic filter capacitors, and a wiring harness terminating at a multi-pin edge connector at the rear. The front panel carries four orange indicator lamps and at least three fuse positions (F1, F2, F5), consistent with a multi-output regulated supply typical of mid-20th-century telecom infrastructure.

Specifications & What's Included

• Manufacturer: Prototype Transformer Corporation (PTC)
• Model / Part Number: 10190-A
• Built For: W.U. Tel. Co. (Western Union Telephone Company)
• Form Factor: Open-frame chassis, benchtop / rack-slide style
• Chassis Color: Olive drab painted steel
• Overall Dimensions: 9.5" W x 8.75" D x 5.25" H
• Internal Components: Two wound transformer cores, one inductor (P/N 10244-A), multiple large blue electrolytic filter capacitors, wiring harness
• Front Panel: Four orange indicator lamps; fuse positions F1, F2, F5
• Rear Connector: Multi-pin card/edge connector
• Country of Manufacture: United States
• Sold as-is unit only — no accessories, cables, or documentation included

Applications

Prototype Transformer Corporation was a U.S. manufacturer that produced custom transformer assemblies and power supply modules for industrial, military, and telecom customers from roughly the mid-20th century onward. This particular unit was purpose-built for Western Union Telephone Company — likely for use within a switching, signaling, or repeater chassis in WU's landline telecom infrastructure. Transformer-based linear power supplies of this type were standard in mid-century telecommunications equipment rooms, providing stable regulated DC voltages to relay logic, line cards, and signaling circuits. The multi-lamp indicator panel and fused outputs are consistent with a supply designed to serve several sub-circuits simultaneously and provide visible fault indication. Units like this are sought today for vintage telecom restoration, military surplus displays, and as parts donors for similar PTC or WU Tel. Co. chassis that share transformer or capacitor specifications.