# William Stanley Jr.'s Early Alternating Current Transformer System

> An 1886 patent describing an early design for an electrical transformer that helped make alternating current power distribution practical for homes and businesses.

- **Patent:** US 349611
- **Original title:** Signoe to geoege westing house
- **Owner:** William Stanley, Jr.
- **Granted:** 1886
- **Status:** Active
- **Times cited:** 12
- **Field:** energy, mechanical

## What it does

This patent details an induction coil system designed to step down high-voltage alternating current (AC) to a lower, safer voltage suitable for lighting and small motors. By using a closed-core transformer, the system allowed electricity to be transmitted efficiently over long distances at high voltages and then converted locally for end-user safety. It effectively solved the problem of power loss that plagued early direct current (DC) systems.

## What it does NOT cover

- Does not cover direct current (DC) power distribution systems.
- Does not cover modern solid-state power electronics or switching power supplies.
- Does not cover polyphase power systems or three-phase generators.

## The clever bit

The use of a closed-core transformer design significantly reduced magnetic leakage, allowing for much higher efficiency than the open-core designs that preceded it.

## Real-world examples

1. The Great Barrington, Massachusetts AC lighting demonstration of 1886
2. Early Westinghouse electrical distribution networks

## Why it matters

This technology was the backbone of the War of Currents between Westinghouse and Edison. It proved that AC could be transmitted over long distances, which ultimately led to the modern electrical grid architecture used globally today.

## Frequently asked questions

### What does William Stanley Jr.'s Early Alternating Current Transformer System cover?

An 1886 patent describing an early design for an electrical transformer that helped make alternating current power distribution practical for homes and businesses.

### Who owns patent US 349611?

William Stanley, Jr. owns this patent, granted in 1886.

### When does this patent expire?

This patent has expired and is now in the public domain — anyone can use the invention freely.

### What is patent US 349611 cited by?

This patent has been cited by 12 later patents that build on its ideas.

### What problem does this patent solve?

This technology was the backbone of the War of Currents between Westinghouse and Edison. It proved that AC could be transmitted over long distances, which ultimately led to the modern electrical grid architecture used globally today.

### What does this patent NOT cover?

Does not cover direct current (DC) power distribution systems.

**Full plain-English explainer:** https://patentbrief.org/patent/us/349611/transformer-stanley

**Original patent:** https://patents.google.com/patent/US349611

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_Source: PatentBrief — https://patentbrief.org. Patent facts are from public records; the plain-English explanation is PatentBrief's._


## Related patents

Semantically similar inventions in the PatentBrief corpus:

- [Nikola Tesla's Early System for Electric Lighting](https://patentbrief.org/patent/us/454622/tesla-coil-electric-lighting) — A 19th-century patent by Nikola Tesla describing an early method for distributing and regulating electric light using high-frequency alternating current.
- [How Nikola Tesla Invented the Modern AC Electric Motor](https://patentbrief.org/patent/us/382280/tesla-ac-motor) — Nikola Tesla's 1888 patent for an induction motor that uses rotating magnetic fields to convert electricity into mechanical motion without needing physical brushes.
- [How Marconi Patented Early Wireless Telegraphy Signals](https://patentbrief.org/patent/us/586193/radio-wireless-marconi) — Guglielmo Marconi's 1897 patent for sending electrical signals through the air to enable early wireless communication.
- [How Georges Claude Invented the Neon Light](https://patentbrief.org/patent/us/1125476/neon-lighting-claude) — A 1915 patent describing the use of neon gas in sealed glass tubes to create bright, colorful light for signs and illumination.
- [Henry Seely's 1882 Electric Flatiron](https://patentbrief.org/patent/us/259054/electric-iron-seely) — An 1882 patent for the first electric flatiron, which used internal heating elements to replace the heavy, fire-heated irons of the Victorian era.