作者steve1012 (steve)
看板Electronics
標題[問題] 電路學
時間Fri Aug 19 22:06:45 2011
出自
Smith 6ed 20頁
An amplifier operating from a single 15-v supply provides a 12-v peak
to peak sin-wave signal to a 1000 歐姆 load and draws negligible input
current from the signal source. The dc current drawn from the 15-v supply
is 8 mA. What is the power dissipated in the amplifier, and what is
the amplifier efficiency?
Ans. 102mW; 15%
我的算法
電源提供的功率為 8x10^-3 * 15 = 0.120 W
輸出的功率為 ( 12/√2)^2/1000 =0.072W
所以在放大器中浪費的功率為 0.120 - 0.072 = 0.048W
也就是48mW 我佈道我哪裡算錯了T_T
--
※ 發信站: 批踢踢實業坊(ptt.cc)
◆ From: 114.34.202.142
→ kameng:12 V peak to peak=6V amplitude 08/19 22:12
→ steve1012:啊shit== 08/19 22:16
→ rogerable:樓上別激動 08/19 22:28
→ a149851571:XDDD 08/20 00:22