电路英文课件 (5)

8/131
3.1.1 单相半波可控整流电路
√若 为定值， 角大， 越小。 若 为定值， 越大， 越大 ，且 平均值Ud越接近零。为解决上述矛 盾，在整流电路的负载两端并联一 个二极管，称为续流二极管，用 VDR表示。 ◆有续流二极管的电路 ☞电路分析 √u2正半周时，与没有续流二极管 时的情况是一样的。 √当u2过零变负时，VDR导通，ud 为零，此时为负的u2通过VDR向VT 施加反压使其关断，L储存的能量保 证了电流id在L-R-VDR回路中流通， 此过程通常称为续流。 √若L足够大，id连续，且id波形接 近一条水平线 。
1
cos a
2
(310)
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3.1.2 单相桥式全控整流电路
☞流过晶I闸dT管 的12 I电d 流0平.45均UR值2 1： c2osa
(3-11)
☞流I过T 晶2闸1p 管ap(的2RU电2 流sin有wt)效2d(值wt)为：U22R
1 sin 2a p a
2p
p
(3-12)
☞为变I 压I2器 二p1次ap侧( 电2RU流2 s有in w效t)2值d (Iw2t与) 输UR出2 直21p流sin电2a流有p 效p a值I(相3-1等3) ，
◆电路分析
☞|u2|>E时，才有晶闸管承受正电压，有导通的可能。
☞晶闸管导通之后，ud=u2，id 关断，此后ud=E。
ud
R
E，直至|u2|=E，id即降至0使得晶闸管
☞与电阻负载时相比，晶闸管提前了电角度 停止导电， 称为停止导电
角。
d sin 1
E 2U 2
(3-16)
☞当 < 时，触发脉冲到来时，晶闸管承受负电压，不可能导通。 16/131

VNBias2
vOUT M2
VNBias2 Rin1
vOUT M2
VNBias2 Rin2
vIN
VNBias1 M1
vIN
VNBias1 M1 vIN
VNBias1
VDD M3
vOUT M2
M1 vIN
VPBias1 VPBias2
VNBias2 Rin3
VNBias1
VDD M4 M3 vOUT M2
VDD M3vOUT
VNBias2 M2
M1 vIN
060609-05
Advantages of the cascode amplifier: • Increases the output resistance and gain (if M3 is cascoded also) • Eliminates the Miller effect when the input source resistance is large
Rin1
=
rds2 1+gm2rds2
≈
1 gm2
Rin2
=
rds2+rds3 1+ gm2rds2
≈
2 gm2
Rin3
=
rds2+rds4gm3rds3 1+ gm2rds2
≈
rds!!!
The input resistance of the common gate configuration depends on the load at the drain.
IBias vIN
vOUT VDD
VNBias1 M1
060609-01
VON3
VON1+VON2 VON1

Power
V2关断而V3开通 时输入出负脉冲
图1-29 典型的直接耦合式GTO驱动电路
V3关断后电阻R3和R4 提供门极负偏压
11
1.7 Protection of power semiconductor devices
Protection circuits Overvoltage protection Overcurrent protection Snubber circuits—specific protection circuits that circuits— can limit du/dt or di/dt TurnTurn-on snubber TurnTurn-off snubber
Supplement: Practical Application Issues of Power Semiconductor Devices
Outline
Practical application issues of power semiconductor devices Gate drive circuit (Section 1.6 in the Chinese textbook) Protection of power semiconductor devices (Section 1.7 in the Chinese textbook) Series and parallel connections of power semiconductor devices (Section 1.8 in the Chinese textbook)
G
O
t
5V的负偏压
Power
iG O
正的门极电流
t
图1-28 推荐的GTO门极电压电流波形

英语
ELECTRICAL ENGLISH
Contents
Unit 1 Job and Workplace Unit 2 Electrical Tools and Materials Unit 3 House Wiring Unit 4 Measuring Instrument Unit 5 Motors and Transformers
Look and Study Dialogue Reading Further Study Words and Phrases
Unit 3
B. Reorder the letters with your partner.
Letters set re ket c so pp su ly s ac ces tec pro t cir cui t n con tai er consum
Look and Study Dialogue Reading Further Study Words and Phrases
Unit 3
布线平面图
Lesson 74
arrangement, a ceiling outlet is switched from two door locations. Similarly, two receptacle outlets on the north wall are switched from two separate locations. The connection between switch and ceiling outlet is drawn with a medium weight solid line, indicating that the connection (conduit or cable) is to be concealed in the wall or ceiling above. The cross lines indicate the conductors in the conduit or cable. If cross lines are omitted, two wires are understood to be in the connection.