| 摘要 |
<p>The invention proposes pulse shapes intended to produce less harmonics than square pulses. The pulses must fit within an envelope between maximum and minimum limit curves 3,5. The first pulse is essentially a square wave with rounded corners 7,201,9. Alternatively the pulse may have stepped rising and falling edges with a non-vertical average gradient (307,309 in Fig. 3) Alternatively the pulse may be an essentially continuous curve (407,401,409 in Fig. 4). The pulse shapes may be produced by driving a DAC (digital to analogue converter) which then drives a current/voltage source.</p> |
