| Year | 1925 |
| Date | 17-Dec |
| Volume | 53 |
| Issue | 1,286 |
| Page | 777 |
| Category | Electrical |
| Part | |
| Title | An Economical Battery-Charging Rectifier |
| Author | H.J.G. |
| Notes | Main frame of buzzer, showing operation of rectifier, practical wiring diagram, sectional elevation of set, buzzer coil connections, plan of instrument board |