| Year | 1917 |
| Date | 22-Mar |
| Volume | 36 |
| Issue | 830 |
| Page | 181 |
| Category | Electrical |
| Part | |
| Title | A Mechanical Rectifier |
| Author | E.T.Painton |
| Notes | 2. The Auto-transformer. Connections, method of forming core, iron loss test connections, section through core, arrangement of secondary turns, the curve of flux density, general arrangement, efficiency curves |