| 摘要 |
1,216,686. Electromagnetic relays. STANDARD TELEPHONES & CABLES Ltd. 18 July, 1968, No. 34168/68. Heading H1N. A quick make, quick break circuit for an electromagnetic device such as a relay having two oppositely wound coils 2, 3 on the same core 1, has one coil 2 in a circuit branch with a switch 7 and the other coil 3 in a circuit branch with a capacitor 8; the two circuit branches being in parallel and connected to a D.C. source 6 through a resistor 5. When the switch 7 is closed the coil 2 is energized from the source 6 and due to the voltage drop at 4 the capacitor 8 will partly discharge through coils 3, 2 which will assist each other to operate the relay. The holding current will be the steady state current in coil 2 after partial discharge of capacitor 8. When the switch 7 is opened the current in coil 2 ceases and opposite magnetization is produced in coil 3 as the capacitor 8 charges to the source voltage. |
