| 1. | In many applications a fluctuating dc current is undesirable .
在许多应用场合，波动的直流电是讨厌的。 |
| 2. | Either direct or alternating current may be used for driving electric trains .
直流电和交流电都可用来驱动电气火车。 |
| 3. | Position control of d. c. motors has been done by means of pulse width modulation .
直流电机位置用脉冲宽度调制法控制。 |
| 4. | Resistance thermometer bridges may be excited from either a-c or d-c sources .
电阻温度计电桥的供电可以是交流电源，也可以是直流电源。 |
| 5. | The difference between a direct and an alternating current is that a direct current always flows in one direction .
直流电和交流电的区别在于直流电总是向一个方向流动。 |
| 6. | Electric cables and wires - method for d . c . voltage test
电线电缆直流电压试验方法 |
| 7. | Effect of contact breakaway muzzle velocity
直流电路触点分离初速度对分断的影响 |
| 8. | The input power is also provided by a dc motor
输入动力也是由直流电机提供的。 |
| 9. | Technical specification of map for d c resistance
直流电阻计量保证方案技术规范 |
| 10. | Simulation of bldc motor control system based on psim
的无刷直流电机控制系统仿真 |
