功放电路图.ppt
第3章功率放大器PPT课件
缺 双电源， 点 电源利用率不高
最大输出功率
主
Pom
1 2
V
2 CC
RL
要 公
直流电源消耗功率
PE
2 VC
CIcm
式 效率 理 想 78.5%
最大管耗 PC1m 0.2Pom
OTL
结构简单，效率高，频率 响应好，易集成，单电源
输出需大电容， 电源利用率不高
Pom
1 8
V
2 CC
RL
PE
1 VC
CIcm
甲乙类工作状态失真大， 静态电流小 ，管耗小，效率较高。
单管甲类电路
做功放适合吗？
乙类推挽电路 iB
0
u BE
UomVCC2UCES
信号的正半周T1导通、T2截止；负半周T2导通、T1截止。 两只管子交替工作，称为“ 推挽 ”。设 β为常量，则负载
上可获得正弦波。输入信号越大，电源提供的功率也越大。
两只管子交替导通，两路电源交替供电，双向跟随。
OTL 电路
输入电压的正半周：
＋VCC→T1→C→RL→地
＋
C 充电。
输入电压的负半周：
C 的 “＋”→T2→地→RL→ C
“ －” C 放电。
静态 uI 时 U B， U EV 2 CC
Uom(VCC
2)UCES 2
C 足够大，才能认为其对交流信号相当于短路。
开启 电压
① 静态时T1、T2处于临界导通状态， 有信号时至少有一只导通；
② 偏置电路对动态性能影响要小。
消除交越失真的互补输出级
静 态UB ： 1B2UD1UD2 动 态ub： 1ub2ui
若I
＞
2
第六章 高频功率放大器-实用PPT
➢工作原理
➢图62 高频功放的工作状态 ➢设输入信号为 ➢
由图61得基极回路电压为
uBE= VBB+Ubmcosωt
（62）
放大器常工作于丙类状态，如图62所示。
输出电流为余弦脉冲,含有直流、 基波(信号频 率分量)和各次谐波分量,输出谐振回路选出基波 分量,就实现了功率放大。
§6.2 谐振式高频功率放大器的工作原理 谐振式高频功率放大器的电路及其特点
晶体管高频功率放大器的原理电路如下图所示, 由晶体管、输出谐振回路和输入回路三部分组成。
图 61 晶体管高频功率放大器的原理电路
➢谐振式高频功率放大器的特点：
①为了提高效率，放大器常工作于丙类状态，晶 体管发射结为负偏置，由Eb（VBB）来保证，流 过晶体管的电流为余弦的脉冲波形；
➢高频功率放大器的主要技术指标 ➢（1）高频输出功率:输出功率 Po ➢（2）效率η: 输出功率/直流电源功率Po/P= ➢（3）功率增益: 输出功率/输入功率Po/Pi ➢（4）带宽B0.7 ➢（5）矩形系数Kr0.1=B0.1/B0.7
➢高频功率放大器的分类 ➢可分为窄带放大器和宽带放大器两类。
晶体管的工作区域 低频区f<0.5fβ ； 中频区f在0.5fβ~0.2fT之间；
高频区f在0.2fT~fT之间。 （ fβ为截止频率，fT为特征频率）
§ 6.3 谐振功率放大器的折线分析法
1. 集电极余弦电流脉冲的分解
如图62所示，集电极电流余弦脉冲是由脉冲高度 Icm和通角θc来决定的。在已知条件下,通过理想化
各次谐波分量的系数为 (2) 在临界工作状态,输出功率最大,且集电极效率也高,常用于发射机的功率输出级，以便获得最大的输出功率。
丙类功率放大器电路组成和工作原理分析PPT课件
ic
C Rp L vc +
Vc c
16
丙类谐振功率放大器
17
丙类谐振功率放大器
ic
+
C
Rp
L vc
vb
+
-
VBB
Vcc
电路正常工作（丙类、谐振）时，
外部电路关系式：
v BE
VBB
Vbm cost
vCE VCC Vcm cost
iC Ic0 Icm1 cost Icm2 cos2t Icmn cosnt
－
呈现为纯电阻，即 谐振电阻RP。
＋－ VBB
－＋ VCC
结论：回路上仅有基波分量产生电压vc，因而在负
载上可得到所需的不失真信号功率。 8
丙类谐振功率放大器
ic
＋
＋
ib V ＋
uce
＋
ube － －
vc C －L
输出
vb=Vbmcoswt
－
＋－ VBB
－＋ VCC
vBE VBB Vbmcost；
低频
推挽，回 低频、高
路
频
推挽
低频
选频回路 高频
3
丙类谐振功率放大器
电路特点：
ic
1、VCC：提供直流能源
＋
＋
2、激励信号大：电 路处于大信号非线 性状态
＋
vb=Vbmcoswt
ib V ＋
uce
ube － －
vc C －L
输出
3、晶体管：承受高电压 － 大电流，截止频率高
4、负载回路：谐振回路
＋－ VBB
vCE VCC Vcm cost
V cm vCE
V CC
概述甲类乙类甲乙类功率放大电路全解ppt课件
资金是运动的价值，资金的价值是随 时间变 化而变 化的， 是时间 的函数 ，随时 间的推 移而增 值，其 增值的 这部分 资金就 是原有 资金的 时间价 值
2. 消除交越失真的OCL电路:工作原理
利用甲乙类双电源互补对称功率放大电路可以消除交跃 失真。
静态： U B1、B2 U R2 U D1 U D2
资金是运动的价值，资金的价值是随 时间变 化而变 化的， 是时间 的函数 ，随时 间的推 移而增 值，其 增值的 这部分 资金就 是原有 资金的 时间价 值
工作原理：
uI正半周主要是 T1管发射极 驱动负载； uI负半周主要是 T2管发射极驱动负载 T1、T2导通时间 uI半个周期 T1、T2工作在甲乙类状态。
UomVCC2UCES
PomU Ro2Lm(VCC2R ULCE)S2
4
78.5%
资金是运动的价值，资金的价值是随 时间变 化而变 化的， 是时间 的函数 ，随时 间的推 移而增 值，其 增值的 这部分 资金就 是原有 资金的 时间价 值
4. 几种电路的比较
变压器耦合乙类推挽：单电源供电，笨重，效率 低，低频特性差。 OTL电路：单电源供电，低频特性差。 OCL电路：双电源供电，效率高，低频特性好。
因此，选择功率BJT时，其极限参数:
I CM i U CEO(BR)
C
max
u CE
V CC RL
max
2V CC
PCM
PT max
0.2
V
2 CC
2RL
资金是运动的价值，资金的价值是随 时间变 化而变 化的， 是时间 的函数 ，随时 间的推 移而增 值，其 增值的 这部分 资金就 是原有 资金的 时间价 值
功率放大器原理及电路图PPT课件
uA=（EC-UCES1） 。
ωt
VT2 ub2
ic2
RL uL
ui负半周时VT2管饱和导通，VT1管截止。VT2管的直流电源由电容C上充 的电尽荷管供每给管，饱u和A=导U通CE时S2的≈0电流很大，但相应的管压降很小，这样，每管的管 耗就很小，放大器的效率也就很高
uA近似为矩形波电压，幅值为（EC-2UCES）。若L、C和RL串联谐振回路调谐 在输入信号的角频率ω上，且回路的Q值足够高，则通过回路的电流ic1或ic2是角频 率为ω的余弦波，RL上可得相对输入信号不失真的输出功率。
0.5fβ fβ 0.2fT fT
第15页/共56页
1 高频功率放大器的动态特性
1、 放大区动态特性方程 当放大器工作在谐振状态时，其外部电路电压方程为：
若设： ub Ubm cost
ic
由上两式消除cos t 可得：
uBE
U BB
Ubm
EC uce U cm
又利用晶体管的内部特性关系式（折线方程）：
Icmax
ic
ic1
ic2 ic3
Ico
ωt
θc
θc
其中各系数分别为：
1
I co 2
icd (t )
I cmax
sinc c cosc ) 1 cosc
I cmax 0
c
1
I cm1 2
c c
ic
costd(t )
1
I cmax (
c
sin c cos c 1 cos c
(4)不能用线性模型电路分析，一般采用图解法分析和折线法
第1页/共56页
功率放大器按工作状态分类：
A（甲）类：导通角为 180o
TEA2025B2.1声道装配音频功放优秀课件
（L.in）——→U2（TEA2025B）第7脚——→U2内部功放2进
行功率放大——→U2第2脚——→L.OUT莲花座——→左音箱
•.
•17
*前面板SD卡模块通过面板按 键，由用户在 外接音源、SD 卡音频、收音机音频 3组信
号之间选择一路输出
音频信号流程在电路原理图 中由红色箭头标出。
•.
•18
低音音箱的喇叭通过排线座CN3接于 TEA2025B内部功放1的输出端（15脚）和 内部功放2的输出端（2脚）之间。
本电路在典型参数工作状态下，输出功率 Po约为4.5W。
•.
•15
电源电路
• 本有源音箱的电源部分使用了一个功率 10W左右，交流输出9V的变压器。
• 变压器次级输出的9V交流电压经排插CN1 接到桥式整流滤波电路，整流滤波后的直 流输出电压约为12V（图中的VCC），该电 压为主电路板的功放电路提供电源。并通 过R3限流降压后，由排插CN4为SD卡模块 供电。
•.
•16
整机音频信号流程
下面以外接音源的左声道为例，说明音频信
号从RCA插座输入，直到左声道扬声器的 整个流程：
外接音源(如手机)——→音频线——→RCA插座的L.INPUT端
子——→排线座VR15第1脚（L.INPUT）——→前面板SD卡
模块的排线座VR14+VR15第1脚（L.INPUT）——→经前面板
• 本电路部分是成品模块，无需学生安装， 只需通过一条组合排线（VR14+VR15）与 主电路板相连。
• 本模块部分主要是提供外接SD卡音频输出 以及收音机信号输出。
•.
•11
主电路板各单元电路原理
• 左右声道功放电路 本电路主要完成各个音源（RCA插座输入 音频、SD卡音频、收音机音频）送来的 左、右2个声道音频信号的功率放大，以 驱动左右声道的2只音箱发声。
《音频功率放大器》PPT课件
电路特征是这类功率放大器的晶体管工作在输出特性曲
线的放大区。在输入信号的整个周期内，晶体管均导通，
有电流流过。
17
第3章 音频功率放大器
甲类功率放大器：
甲类功率放大器的优点 是失真极小，各项电声 指标高。在Hi-Fi音响领 域里很多厂家选用此种 功放，如英国罗特功放、 音乐传真功放和日本的 金嗓子功放都是甲类功 率放大器。
12
第3章 音频功率放大器
(3)V―MOS功率放大器。
金属栅极采用V型槽结构 ； 漏极是从芯片的背面引出 ， 具有垂直导电性。由于在栅极 与芯片之间有二氧化硅绝缘层， 因此它仍属于绝缘栅型MOS 场效应管。
因为场效应管是电压控制的器件，它具有负温度特性， 因此无需对输出管进行复杂的保护，而且它具有和电 子管相似的音色。采用场效应管制作的功放具有噪声 低、动态范围大、无需保护等特点。其电路简单，而 性能却十分优越。
13
第3章 音频功率放大器
(3)V―MOS功率放大器。
VMOS场效应管（V-MOSFET）简称VMOS管或功 率场效应管，其全称为V型槽MOS场效应管。它是继 MOSFET之后新发展起来的高效、功率开关器件。它 不仅继承了MOS场效应管输入阻抗高、驱动电流小 （0.1μA左右），还具有耐压高（最高1200V）、工作 电流大（1.5A～100A）、输出功率高、低频跨导的线 性好、开关速度快等优良特性。正是由于它将电子管 与功率晶体管之优点集于一身，因此在电压放大器 （电压放大倍数可达数千倍）、功率放大器、开关电 源等电路中获得广泛应用。
第3章 音频功率放大器
第3章 音频功率放大器
第5章 功率放大电路
集电极电 流波形
QA
ICQ
=2
uCE
0
2 ωt
(2) 乙类放大电路 静态工作点在截止区，如图5.1.3所示，静态集电极电流 为零，无静态功耗，但输出波形严重失真。 iC 特点 集电极电 流波形 iC2 a. 静态功耗 =π
PC U CEQ I CQ 0
b. 能量转 换效率高
QA
0 uCE
给功率管（T1和T2）一定的直流偏置，使其工作于微 导通状态，即甲乙类工作状态。 U CC (1) 甲乙类互补推挽电路 a. 利用二极管提供偏压 电路如图5-6所示 二极管提供偏 压，使T1、T2 呈微导通状态
2 U CC 4 PT1(U om U CC ) ( ) 0.137Pom RL 4
这是不是最 在理想情况下（即无静态电流，忽略管子饱和压降）， 大的管耗呢？
2 1 U CCU om U om 求管耗的极值： PT 2 PT1 ( ) RL 4
令
dPT 1 2VCC U om 0 dU om RL π
uo
T2
RL
静态功耗为零
U CC
图5-2(a)乙类OCL功放电路原理图
b. ui >0 时 T1导通，T2截止
c. ui <0 时
T2导通，T1截止
输入信号ui
0 t
U CC
U CC
ui
0 t
T1
ic1
RL
ui
T2
电流io方向
ic 2
RL
uo
输入信号ui 电流io 方向
uo
uo≈ui
uo≈ui
5.2 乙类互补对称功率放大电路
2822单声道功放电路
二、参数
• 电源电压: 2V-12V 输出功率: 2W (1KHz,8Ω,9V,10%总失 真) 静态电流: ≤9mA (Vcc=3V) 谐波失真: 0.2% (1kHz，8Ω～32Ω) 闭环增益: 39dB (典型值) 负载范围: ≥4Ω
三2单声道功放电路
一、说明
• TDA2822M是意法半导体(ST)早期专门为 便携式录放音设备开发的双通道单片功率 放大集成电路，具有低交越失真和低静态 电流的特点，适用于立体声和桥式放大 (BTL)方式。TDA2822M还有一个独特之处 就是工作电压范围很宽，在2V-12V范围内 都可以正常工作，不过除非是用于耳机放 大器，最好还是让TDA2822M工作于3V以 上电压。 本电路是用一块TDA2822M功放集成电路 接成单声道的桥式放大(BTL)方式，很少的 外围元件，不用装散热器，放音效果也令 人满意。
高峰功放电路图101229
Models:Power Base-1, 2 & 3© 1996 by Crown International, Inc., P.O. Box 1000, Elkhart, Indiana46515-1000 U.S.A. Telephone: 219-294-8000. Power-Tech amplifiersare produced by the Professional Audio Division of CrownInternational, Inc. Trademark Notice: Power Base-3™ is a trademarkand Power Base-1®, Power Base-2®, Crown,®IOC® and ODEP® areregistered trademarks of Crown International, Inc. Other trademarksare the property of their respective owners.®E106377Applies only to 120 VAC,North American PB-1,PB-2 and PB-3 units.101229-112/96Applies only to 120 VAC,North American PB-1and PB-2 units.®LL 32521CThe lightning bolt triangle is used to alert the user to the risk of electric shock.The exclamation pointtriangle is used to alert the user to important operatingor maintenance instructions.The information furnished in this manual does not include all of the details of design, production, or variations of the equipment. Nor does it cover every possible situation which may arise during installation, operation or mainte-nance. If you need special assistance beyond the scope of this manual, please contact our T echnical Support Group.Crown Audio Division Technical Support GroupPlant 2 SW, 1718 W. Mishawaka Rd., Elkhart, Indiana 46517 U.S.A.Phone: 800-342-6939 (North America, Puerto Rico and Virgin Islands) or 219-294-8200Fax: 219-294-8301 Fax Back: 800-294-4094 (North America only) or 219-293-9200Internet: Power Base Series Power AmplifiersPage 41Welcome 71.1Unpacking 71.2Features 72Installation 92.1Stereo 92.2Mono 92.3102.4.......................................102.5103Operation 113.1113.2113.3113.3.1ODEP 113.3.2113.3.3Drive Protection 113.3.4.....................123.3.5123.4Controls 123.5124135Accessories 195.1195.2MT-BB 196Service 206.1Worldwide Service 206.2206.2.1206.2.220Power Base Series Power AmplifiersPage 51.17.......................................892.3Power Base Input Wiring 92.4Input Sensitivity Switch 1010121516161718185.1The MT-XLR 1919Power Base Series Power AmplifiersPage 7Power Base ODEP ®)MT-BB ac-Power PowerPower Base Series Power AmplifiersPage 8Power Base Series Power AmplifiersPage 92 InstallationAlways remove power from the unit and turn the level controls off (fully counterclockwise) when making or breaking connections. This reduces the chance of blasts that can cause loudspeaker damage.The guidelines below are provided to help you quickly get your amplifier installed and ready to go. Be sure to follow the instructions in Sections 2.1 and 2.2 for the selected mode of operation. Additional information on input sensitivity, load protection and required AC mains is provided in Sections 2.3, 2.4 and 2.5.1.Install the amplifier in a standard 19 inch (48.3 cm) rack or place it on a stable surface. The mounting dimensions are 19 inches (48.3 cm) wide, 3.5 inches (8.9 cm) tall and 16 inches (40.6 cm) deep behind the mounting sur-face. IMPORTANT! Allow for adequate ventilation.2.1 Stereo1.Turn down the level controls (fully counterclockwise) and turn off the amplifier.2.Set the back panel stereo/mono switch to Stereo.3.If present, remove the Parallel-Mono jumper.4.Connect the input and output cables as shown in the first example in Figure 2.1.5.Turn on the amplifier and adjust the level for each chan-nel using the back panel level controls.CAUTION: Never parallel the two outputs by di-rectly tying them together, and never parallel them with the output of another amplifier.2.2 MonoYour amplifier’s mono modes provide double the power of Stereo mode in a single channel. In Bridge-Mono mode, the outputs are wired in series for twice the output voltage. In Parallel-Mono mode, the outputs are paralleled for twice the current capacity.Bridge-Mono mode is provided for loads with an im-pedance greater than 4 ohms. Parallel-Mono mode should be used with loads of 4 ohms or less.B R I D G E - M O N O1.Turn down the level controls (fully counterclockwise) and turn off the amplifier.2.Set the back panel stereo/mono switch to Bridge-Mono.3.If present, remove the Parallel-Mono jumper.4.Connect the input and output cables as shown in the sec-ond example in Figure 2.1. Only use the channel 1 input.5.Make sure the load is balanced (neither side shorted to ground) and do not use the black (–) binding posts.6.Turn on the amplifier and adjust the level. Only use thechannel 1 level control.P A R A L L E L - M O N O1.Turn down the level controls (fully counterclockwise) and turn off the amplifier.2.Set the back panel stereo/mono switch to Parallel-Mono.3.Install a solid, 14-gauge (2 mm 2) or heavier jumper wire across the two red (+) binding post outputs.4.Connect the input and output cables as shown in the third example in Figure 2.1. Only use the channel 1 input.5.Turn on the amplifier and adjust the level. Only use the channel 1 level control.CAUTION: With Parallel-Mono wiring, do not switch to Stereo or Bridge-Mono mode until the output jumper wire is removed.AIR FLOWFig. 2.3 Power Base Input Wiringe high-quality loudspeaker cables to connect the load to the amplifier’s outputs. Do not use shielded cable.e shielded cables to connect audio sources to the amplifier inputs. Either balanced or unbalanced wiring can be used as shown below. (XLR connectors are avail-able with the MT-XLR accessory. See Section 5.)Fig. 2.2 Do NOT Block Air FlowPower Base Series Power AmplifiersPage 10Page 113.3.1 ODEPCrown invented ODEP to keep the amplifier working under demanding conditions and to increase output efficiency. To do this, Crown established a rigorous pro-gram to measure each transistor’s safe operating area (SOA). Intelligent circuitry was then designed to simu-late the instantaneous conditions of the output transis-tors. Its name describes what it does: Output Device Emulation Protection, or ODEP . In simple terms, ODEP compares transistor conditions to their known SOA. If more power will be asked of them than they can deliver under the existing conditions, ODEP limits the drive until conditions fall within the SOA. Limiting is propor-tional and kept to an absolute minimum—only what is required to prevent output transistor damage. Under normal conditions, no limiting is required and ODEP is transparent to the audio signal.ODEP makes possible a quantum leap in output effi-ciency and reliability—with ODEP , the show goes on.3.3.2 Ultrasonic and Radio Frequency ProtectionAn amplifier’s slew rate only needs to be large enough to deliver the maximum voltage at the highest required frequency. Higher slew rates actually allow undesirable ultrasonic and radio frequencies to be reproduced. By design, Power Base amplifiers have a controlled slew rate to limit the highest frequencies that they reproduce.Limiting occurs well above 20 kHz so there is no au-dible effect on performance. This approach protects the amplifier from radio frequencies and can even pro-tect some sensitive loads (including some tweeters).3.3.3 Drive ProtectionThe drive protection system temporarily removes output drive to protect the amplifier and its loads. Drive protec-tion can be activated in two situations. First, if dangerous subsonic frequencies or direct current (DC) is detected in the amplifier’s output, the unit will activate its DC/low-frequency protection circuitry which puts the amplifier in drive protection mode. This protects the loads and pre-vents oscillations. The unit resumes normal operation as soon as the amplifier no longer detects dangerous out-put. Although it is extremely unlikely that you will ever activate the amplifier’s DC/low frequency protection system, improper source materials like subsonic square waves or input overloads that excessively clip the input signal can activate this system.The amplifier’s fault protection system will put the am-plifier in drive protection mode in rare situations whereheavy common-mode current is detected in the output.3 Operation3.1 PrecautionsAlthough your amplifier is protected from external faults,the following safety precautions are recommended:1.There are important differences among the Stereo,Bridge-Mono and Parallel-Mono operating modes.Please refer to Sections 2 for additional information.2.WARNI NG: Do not change the position of the stereo/mono switch unless the amplifier is first turned off.3.CAUTI ON: I n Parallel-Mono mode, a jumper is used to connect the red binding post outputs.Be sure to remove this jumper for Bridge-Mono or Stereo mode, or high distortion and excessive heating will occur. Also, make sure the stereo/mono switch is set to the proper e care when making connections, selecting sig-nal sources and controlling the output level. The load you save may be your own!5.Do not short the ground lead of an output cable to the input signal ground. This will form a ground loop and may cause oscillations.6.Operate the amplifier from AC mains of not more than 10% variation above or below the selected line voltage and only at the specified line frequency.7.Never connect the output to a power supply out-put, battery or power main. Such connections may result in electrical shock.8.Tampering with the circuitry by unqualified person-nel or making unauthorized circuit changes may be hazardous and invalidates all agency listings.Remember: Crown is not liable for any damage that re-sults from overdriving other system components.3.2 Power IndicatorWhen lit, the amber power indicator (to the left of the power switch) shows that the amplifier has been turned on. It is driven only by the low-voltage power supply and does not indicate the status of the high-voltage supplies.3.3 Protection SystemsPower Base amplifiers have extensive protection sys-tems, including ODEP , ultrasonic/RF protection, drive protection, transformer thermal protection and fuses or circuit breakers that protect the power supplies.The unit should never output heavy common-mode cur-rent unless its circuitry is damaged. Activating drive protection helps prevent further damage.3.3.4 Transformer Thermal ProtectionAll Power Base amplifiers have transformer thermal protection. This protection circuitry is activated in un-usual situations where the unit’s transformer tempera-ture rises to unsafe levels. Under these abnormal conditions, the unit removes power to the high-voltage transformer. The fan will continue to run in all units ex-cept those with 220/240 VAC transformers. The ampli-fier will return to normal after it cools to a safe temperature.It is very unlikely that your Power Base amplifier will ever activate transformer thermal protection as long as it is operated within rated conditions. Your amplifier is designed to continue operating under conditions where other amplifiers would fail. But even when you exceed the limits of a Power Base amplifier, it still pro-tects itself—and your investment—from damage.3.3.5 Fuses and Circuit BreakersAll 120 VAC, 60 Hz units and all Power Base-3 units have a fuse that protects the low-voltage power supply and cooling fan. The Power Base-1 and Power Base-2 high-voltage power supplies are protected by fuses, while the Power Base-3 high-voltage power supplies are protected by a circuit breaker. With rated loads and output levels, these fuses (or the circuit breaker) should only shut down the amplifier in the incredibly rare instance of a catastrophic amplifier failure. The ODEP protection system keeps the amplifier opera-tional under most other severe conditions. The fuses (or breaker) can also shut down the amplifier in situa-tions where extremely low-impedance loads and high output levels result in excessive current draw.A Power Base amplifier will not blow its fuses or trip its breaker unless something is wrong. In the rare event that an internal fuse blows, please refer the unit to a qualified technician. If the breaker in a Power Base-3 trips, try to identify and correct the problem before re-setting it with the back panel Circuit Breaker Reset. If the problem persists, refer the unit to a qualified techni-cian.3.4 ControlsThe Power switch is th only control located on the front panel. All others are located on the rear, including the level controls.When making any setup or wiring changes, don’t forget to turn off the amplifier, turn down the level controls and disconnect the power cord. Be sure to turn down (full counterclockwise) the channel 2 level control when us-ing either mono mode. The Parallell Mono/Stereo/ Bridge Mono switch is used to select Stereo, Bridge-Mono or Parallel-Mono operating modes. The Input Ground Lift switch isolates the phone jack input grounds from the chassis ground to help prevent ground loops. It does not affect any installed input ac-cessories. The Input Sensitivity Switch, located inside the back cover plate, sets the amplifier’s input sensitiv-ity (refer to subsection 2.3 for information on changing this switch). And the Power Base-3 has a back panel Circuit Breaker Reset button that resets the circuit breaker (refer to subsection 3.3.5).CHANNEL 2CHANNEL 13.5 Filter CleaningA dust filter is provided on the unit’s air intake. If it be-comes clogged, the unit will cool less efficiently and may produce lower output levels. To clean the filter, use a phillips screwdriver to remove the three screws the secure the front grille. Use mild dishwashing deter-gent and warm water for best cleaning results. Be sure the filter is dry before you reinstall it. Replacement fil-ters may be ordered from the factory.Dust filters are not 100% efficient—long term this may require internal heat-sink cleaning by a qualified tech-nician. Internal cleaning information is available from our Technical Support Group.Fig. 3.1 Back Panel Level ControlsPage 124 Specificationsand an input sensitivity of 26 dB unless otherwise specified. Standard 1 kHz Power:watts at 1 kHz with 0.1% THD+noise.Full Bandwidth Power:watts from 20 Hz to 20 kHz with 0.1% THD+noise.120 VAC, 60 Hz Units:formers for 120 VAC, 60 Hz power mains.PerformanceFrequency Response:at 1 watt.Phase Response:at 1 watt.Signal-to-Noise:bandwidth power from 20 Hz to 20 kHz.Total Harmonic Distortion (THD):ing linearly to 0.1% at 20 kHz.Intermodulation Distortion (IMD):bandwidth power.Damping Factor:CrosstalkPower Base-1: Greater than 75 dB below full band-greater than 60 dB at 20 kHz.Power Base-2: Greater than 90 dB below full band-greater than 66 dB at 20 kHz.Power Base-3: Greater than 90 dB below full band-greater than 70 dB at 20 kHz.Common Mode Rejection (CMR):falling linearly to better than 50 dB at 20 kHz.Controlled Slew Rate: Greater than 13 volts/ms.Voltage Gain:dB position).Power Base-1: 51:1 ±12% or 34.3 dB ±1 dB at 0.775 sensitivity.Power Base-2: 64:1 ±12% or 36.2 dB ±1 dB at 0.775 volt sensitivity; 35:1 ±12% or 31.0 dB ±1 dB at 1.4 volt sensitivity.Power Base-3: 83:1 ±12% or 38.4 dB ±1 dB at 0.775 volt sensitivity; 46:1 ±12% or 33.3 dB ±1 dB at 1.4 volt sensitivity.The following specifications are guaran-Power Base-1Stereo mode (both channels driven):240watts into 4 ohms.200watts into 8 ohms.Bridge-Mono mode:455watts into 8 ohms.395watts into 16 ohms.Parallel-Mono mode:455watts into 2 ohms.400watts into 4 ohms.Power Base-2Stereo mode (both channels driven):460watts into 4 ohms.325watts into 8 ohms.Bridge-Mono mode:910watts into 8 ohms.660watts into 16 ohms.Parallel-Mono mode:920watts into 2 ohms.655watts into 4 ohms.Power Base-3Stereo mode (both channels driven):760watts into 4 ohms.540watts into 8 ohms.Bridge-Mono mode:1525watts into 8 ohms.1090watts into 16 ohms.Parallel-Mono mode:1530watts into 2 ohms.1080watts into 4 ohms.Safe with all types of loads. RatedPage 13Required AC Mains: Current, frequency and voltage requirements are provided on each unit’s back panel. All models draw 90 watts or less at idle.Power Base-1: Draws up to 6 amps of current.Power Base-2: Draws up to 10 amps of current.Power Base-3: Draws up to 15 amps of current.Low-Voltage Power Supply: A ±24 VDC fanformer supply (fan motor winding) regulated to ±15 VDC.AC Connector: An appropriate AC line cord and plug are provided. 120 VAC, 60 Hz units have a standard 3-wire, 15-amp grounded connector (NEMA 5-15P). ControlsPower: A front panel rocker switch used to turn the amplifier on and off.Level: A back panel rotary potentiometer for each chan-nel used to control the output level.Stereo/Mono: A three-position back panel switch used to select Stereo, Bridge-Mono or Parallel-Mono mode.Sensitivity: A three-position switch inside the back cover plate used to select the input sensitivity for both channels: 0.775 volts or 1.4 volts for standard 1 kHz power, or 26 dB voltage gain (see Section 2.3).Input Ground Lift: A two-position back panel switch used to isolate the phone jack and chassis grounds. Reset (Power Base-3 only): A back panel push but-ton used to reset the circuit breaker that protects the power supplies.IndicatorsPower: This amber indicator shows the on/off status of the low voltage power supply.Input/OutputInput Connector: Balanced ¼ inch phone jacks. See Section 5 for XLR and barrier block accessories.I nput I mpedance: Nominally 20 K ohms, balanced;10 K ohms, unbalanced.Output C onnector:T wo s ets o f c olor-coded 5-way b binding posts (for banana plugs, spade lugs or bare wire). Output Impedance: Less than 10 milliohms in series with less than 2 microhenries.DC Output Offset:Less than 10 millivolts.Output SignalStereo: Unbalanced, two-channel.Bridge-Mono: Balanced, single-channel. Channel 1 controls are active; Channel 2 controls should be turned down and not used.Parallel-Mono: Unbalanced, single-channel. Channel 1 controls are active; Channel 2 controls should be turned down and not used.ProtectionPower Base amplifiers are protected against shorted, open or mismatched loads; overloaded power supplies; excessive temperature, chain destruction phenomena, input overload and high-frequency blowups. They also protect loudspeakers from input and output DC, as well as providing protection from turn-on/turn-off transients.If operating conditions are unreasonable, the patented ODEP circuitry proportionally limits the drive level to pro-tect the output transistors, particularly in the case of el-evated temperature. A thermal switch imbedded in the transformer protects the power supplies from overload. In the rare event that a transformer overheats, the ther-mal switch removes power, waits until the unit has cooled to a safe temperature and then resets itself.Turn On: Four second delay with no dangerous tran-sients. Contact us if you need to change the delay. ConstructionDurable black finish on steel chassis with special “flow-through” ventilation from front to side panels.Cooling: Internal heat sinks with forced-air cooling for rapid, uniform heat dissipation.Dimensions: Standard 19-inch (48.3 cm) rack mount width (EIA RS-310-B), 3.5-inch (8.9 cm) height and 16-inch (40.6 cm) depth behind the mounting surface. Approximate Weight: Center of gravity is 6 inches (15.2 cm) behind front mounting surface.120 VAC, 60 Hz Units:Power Base-1: 30 pounds (13.6 kg) net; 34 pounds(15.4 kg) shipping weight.Power Base-2: 34 pounds (15.4 kg) net; 38 pounds(17.2 kg) shipping weight.Power Base-3: 36 pounds (16.3 kg) net; 40 pounds(18.2 kg) shipping weight.Page 14” Each ofguaranteed to meet or exceed their specifications for three years. Further, because our published specs are set below our “in-house” measurements, you can expect everyPage 15Page 16Page 17Page 185 AccessoriesThere are two accessories available at the time of this printing: the MT-XLR and the MT-BB. Important: The MT-XLR and MT-BB must be installed at a Crown Factory Service Center or the Crown factory.5.1 MT-XLRThe MT-XLR is an accessory panel that provides two standard 3-pin female XLR input connectors. The MT-XLR accessory makes it easy to quickly change connections in a system that uses standard XLR con-nectors. It can also be used in systems that need to daisy chain an input signal from one amplifier to an-other. Because the MT-XLR connectors are wired in parallel with the amplifier’s built in phone jack connec-tors, an input signal fed to either input can be fed to another amplifier from the unused connector for that channel.5.2 MT-BBThe MT-BB is an accessory panel that provides barrier strip input connectors. An MT-BB accessory might be desirable in applications requiring bare wire connec-tions. It can also be used to daisy chain an input signal from one amplifier to another just like the MT-XLR.Fig. 5.1 The MT-XLRFig. 5.2 The MT-BBPage 196 ServiceThis unit has very sophisticated circuitry which should only be serviced by a fully trained technician. This is one reason why each unit bears the following label: CAUTI ON: To prevent electric shock, do not re-move covers. No user serviceable parts inside. Re-fer servicing to a qualified technician.6.1 Worldwide ServiceService may be obtained from an authorized service center. (Contact your local Crown/Amcron representa-tive or our office for a list of authorized service centers.) To obtain service, simply present the bill of sale as proof of purchase along with the defective unit to an authorized service center. They will handle the neces-sary paperwork and repair.Remember to transport your unit in the original factory pack. We will pay the surface shipping costs both ways for warranty service to the authorized service center nearest you after receiving copies of all ship-ping receipts. You must bear the expense of all taxes, duties, and customs fees when transporting the unit.6.2 North American ServiceService may be obtained in one of two ways: from an authorized service center or from the factory. You may choose either. It is important that you have your copy of the bill of sale as your proof of purchase.6.2.1 Service at a North American Service CenterThis method usually saves the most time and effort. Simply present your bill of sale along with the defective unit to an authorized service center to obtain service. They will handle the necessary paperwork and repair. Remember to transport the unit in the original factory pack. A list of authorized service centers in your area can be obtained from our Technical Support Group. 6.2.2 Factory ServiceTo obtain factory service, fill out the service informa-tion page that follows and send it along with your proof of purchase and the defective unit to the Crown factory. For warranty service, we will pay for ground shipping both ways in the United States after receiving copies of the shipping receipts. Shipments should be sent “UPS ground.” (If the unit is under warranty, you may send it C.O.D. for the cost of freight via UPS ground.) The fac-1.When sending a Crown product to the factory forservice, be sure to fill out the service informationform that follows and enclose it inside your unit’sshipping pack. Do not send the service informa-tion form separately.2.T o ensure the safe transportation of your unit tothe factory, ship it in an original factory packingcontainer. If you don’t have one, call or writeCrown’s Parts Department. With the exception ofpolyurethane or wooden crates, any other pack-ing material will not be sufficient to withstand thestress of shipping. Do not use loose, small sizepacking materials.3.Do not ship the unit in any kind of cabinet (woodor metal). Ignoring this warning may result in ex-tensive damage to the unit and the cabinet. Ac-cessories are not needed—do not send theinstruction manual, cables and other hardware.Always use theoriginal factory packto transport the unit. Crown Audio DivisionT echnical Support / Factory ServicePlant 2 SW, 1718 W. Mishawaka Rd., Elkhart,Indiana 46517 U.S.A.T elephone:219-294-8200800-342-6939 (North America,Puerto Rico, and Virgin Islands only)Facsimile:219-294-8301 (Technical Support)219-294-8124 (Factory Service)Fax Back:219-293-9200800-294-4094 (North America only) Internet:Page 20。
丙类谐振功放的工作原理及特性分析汇总PPT课件
完成以下功能：
＊选频滤波 ＊阻抗匹配
由于RL比较大，所以，谐振回路的品质因数比较小； 但不影响谐振回路对谐波成分的抑制作用。
第13页/共68页
仿真1 仿真2
13
uBE
uBE(on)
uim
t
–VBB
iB
t iC
uc Ucm
Ucm
t
VCC t
高频功率放大器中各分电压与电流的关系
iB
+
L+
输入端： uBE VBB Uim cost +
+ uBE
uCE
–
C
uc
ui –
RL –
输出端： uCE VCC Ucm cost
+ VBB –
– VCC +
其中： uc UCm cost
第30页/共68页
动态特征曲线的画法：
ic
(1) 作 A 点:
A
•
令 t 0 o
A
:
ube uce
1 1( ) Ucm 2 0( ) VCC
1 2
g1 (
)
若ξ=1时，
c
1 2
g1( )
n()
0.6
g1()
θ值越小，g1(θ)值越大，效 率越高。
0.5 2.0
0.4
0.3 1.0
0.2
g1 ()
1 () 0 () 2()
0.1
3()
0 20 40 60 80 100 120 140 160 180 °
式中： Ico为直流电流分量 iC1为基波分量； iC1=Icm1COSωct iC2为二次谐波分量；iC2=Icm2COS2ωct
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例:互补对称OTL功放电路如图所示，已知VG=24V，RL=8Ω。 求：（1）要使电路理想工作，静态时，A点电位为多少？调节哪个元 件来达到要求？
（2）RP2的作用是什么？ RP2一旦开路将产生什么后果？ （3）电路中R4、C4的作用是什么？如果去掉R4、C4对电路会有什么 影响？
（4）若A点电位为14V，则该电路最大输出功率和此时的效率各是多 少？
（5）若输入信号 ui 500 sin tmV Au1=-10,Au2=1,此时输出功率PO
和效率η各为多少？
带有前置放大级的甲乙类OCL功放
电路
甲类
电路类型
甲类
静态电流
大
最大不失 真输出电 压幅值 Ucem
最大不失 真输出功 率Pom 最高效ηm
电源产生的 功率
最大管耗Pcm
电路特点
乙类推挽 乙类 为零
第7章 低频功率放大器
甲类单管功放电路
乙类推挽式功放电路
甲乙类推挽功放电路
ic
ic1
ic1
0
ic2
uCE2
0
直流负载线
1 vGQ20来自uCE1交流负载线
0
ic2
uce
ucem
输入变压器倒相式OTL电路
互补対称式OTL电路
没有自举电路时的正半周输出等效简图
有自举电路，功放正半周输出（此时ui应为负半周，
因为前置放大级为共射电路，有反相作用）时的简化电路
如图所示。该电路的工作，将在R3上形成一定的压降
uR3=R3iR3,同时V2管发射结也会有一部分的压降uBE2，这样 就造成了uA远不能达到UG。也就是说，该电路正半周输出 的振幅较小，远不能达到UG/2，电路的功率输出也就比较 小。
加上自举电路后，由于R4较小，故静态下UM≈UG。电路 正半周输出时，由于大电容C4的作用，可使uM随uA同幅上 升（uM的升幅刚好弥补了这一过程中的uR3和uBE2的压降）， 当uA由UG/2升至UG时，uM同时由UG升到达3UG/2。由此可见， 自举电路提高了正半周输出的振幅，使其最多可达UG/2。
输入变压器 倒相式OTL
甲乙类
互补对称式 OTL
甲乙类
OCL 甲乙类
很小
很小
很小