| In the simplest case, the wires carrying the electrical signals are used to form an electromagnet which attracts and releases a metal diaphragm. |
| The development of the electromagnet about 1837 provided the American Samuel F. B. Morse with a way to transmit and receive electric signals. |
| As early as 1826 the inventor of the electromagnet William Sturgeon had tried to open pallets with his invention. |
| They mounted two flat, semicircular metal chambers between the faces of a powerful electromagnet. |
| An electromagnet records bits by magnetizing small areas of the crystalline film covering the disk. |
| The betatron consists of a doughnut-shaped evacuated chamber placed between the poles of an electromagnet. |
