根据我的经验，发射极-输出放大器通常是交流耦合的输入和输出:
然而，最近我遇到这样一个放大器DC-coupled——取而代之的是电阻电容C1和C2: < / p > < p > < img src = " https://i.stack.imgur.com/f6IQkm.png " alt = "原理" / > < / p > < p >这个电路是用于视频信号,Vin 1.5 vp-p信号来自DAC,和输出电压应该是0.7 vp-p 75欧姆的信号。
这个放大器的行为与交流耦合版本有什么不同?
直流耦合比交流耦合鲁棒性差吗?例如，放大器是否只有在输入信号有一定的直流偏置时才能工作?它是否需要DAC有一个特定的输出阻抗?< / p >
Why might the designer have chosen to DC-couple this amplifier rather than use the more robust AC-coupling?
我知道V = Q / C，但我不是很熟悉电容，特别是有这么多的变化，它的公式，而不是一个通用的。有一个通用的公式吗?电容真的取决于配置吗?< / p >
When it comes to the formula here used for potential difference, I would really like to know. Why is the formula constructed in such a way? Why is the coefficient at the bottom 2? I see different formulas that have 4 as the coefficient. How do I not get confused on what is the correct coefficient to use, or configuration I should refer to in capacitance. I want to be able to study this in a way that I would depend on what the general concepts are and not just memorize the formula. Thank you.
我正在尝试学习VHDL，并试图做一个简单的4到1 MUX。下面是我的代码:
LIBRARY ieee;使用ieee.std_logic_1164.all;PORT(i0, i1, i2, i3, s0, s1: IN STD_LOGIC;输出:OUT STD_LOGIC);mux_4to1结束;= (i0 AND NOT s1 AND NOT s0) OR (i1 AND NOT s1 AND s0) OR (i2 AND s1 AND NOT s0) OR (i3 AND s1 AND s0) OR (i2 AND s1 AND NOT s0) ORlogicfunc结束;当我尝试使用Quartus Prime 20.1 Lite编译代码时，我得到以下错误:
我尝试删除分号，添加"begin" before declaring the ports, and many other things. What fixed the error was typing "IN" in front of i0 and "OUT" in front of output, looking at the error produced then, and then deleting the added "IN" and "OUT".
Does anyone have any idea what was causing the error?
我在住宅建设中做了一些基本的电气工作，但我正在尝试将50安培的插座改装成20安培的插座，以便为一台非常昂贵的机器供电。我注意到50安培的插座有三根引线和一个接地。一些初步的谷歌搜索表明它们是不同的115v导线。这让我犹豫了一下，是否只信任Amazon上的适配器，并将我昂贵的机器插入适配器。所以我打算买一个万用表，检查一下情况，确保它不会造成任何损坏。我模模糊糊地意识到，错误的电压会损坏部件，过大的电流是可以的，电阻是由负载决定的，交流电源比这更重要。
如果您愿意的话；如果交流电源不正确，会损坏设备的各个方面，我可以得到一份清单吗？例如，我怀疑；阶段“；或；极性；它们可能很重要。然而，我不知道这些东西是什么，因为电子不是我的专业或职业。多谢各位
Preface:
One solution to making a good mixed signal pcb design (without high currents that can create a voltage drop across a plane) is -to make a single ground plane -to place the digital parts together -to place the analog parts together, separated from the digital parts. -to connect the returns of the analog and digital parts to the single ground plane -to ensure that currents flowing to/from analog parts do not cross the paths of current flowing to/from digital parts until as close as possible to the power supplies. (No digital power plane over an analog power plane)
Things get messy when you have and ADC and DAC in the board. The ADC and DAC have separate analog and digital return pins. However, to get specified performance these pins must be joined to the single plane very close together at the "border" of the analog region and digital region of the plane.
There are 40-50 signals going to the 60 MHZ 14 bit ADC and DAC including LVDS, differential clocks, SPI's, and differential analog inputs and outputs.
To the PCB designer, it is not clear whether these signals must be classified as analog or digital so he can locate the traces appropriately.
Using Altium, what is the best way to add the "keep over analog region" or "keep over digital region" meta-data to each net so that the PCB designer can use rules?
在adc环境下VDD和VRef有什么区别?< / p >
该设备是一个相当大的单片单元，那么为什么不内置电阻器?< / p >
我制作了一个简单的离散电容器+电阻延时电路的电路原理图，使用1500uf电容器和100kOhm电阻作为计时机制。激活瞬时按钮开关时，电容器应充满，然后通过100kOhm电阻器缓慢放电到两个晶体管的基极，打开流入另一个电容器（连接到晶体管2）的电流然后，当第二个电容器最终通过唯一的开路路径（通过10欧姆电阻器进入负载）放电时，它会持续放电并重新填充，直到第一个电容器耗尽电荷，晶体管闭合。当另一个晶体管打开时，它应该充当NOT开关，从第二个电容充电并将其发送到中性点，而不是通过10欧姆电阻器，但是当我在带有3V币形电池单元作为电源的perf板上测试电路时，无论是否按下按钮，它都不提供输出。LED也不亮。我在下面附上了示意图，如果您能帮我找到解决方案，我将非常感激，因为我的第一个真实电路
My problem is caused by the voltage drop produced by those resistive wires. It is so significant that the battery pack can't power the motor any more (requires 12V). Is there some way to eliminate this, without adding one more battery pack or any other power source?
My cells: https://eu.nkon.nl/eve-inr18650-26v-2550mah-7-65a.html
I've got a Wye configuration of resistors and am giving DC values 1V, 2V, and 4V to points A, B, and C respectively. I want to calculate the current seen in each resistor.
Is this solved with Thevenin equivalents? College physics was 20+ years ago and I'm quite rusty -- thank you :)
我想知道我的选择是什么，我需要采取什么预防措施来确保我的项目是安全的。< / p >
Ideally I would like to use a powder coated aluminum enclosure, as it matches the aesthetics of my past projects and also because I have a supplier that can do machining / uv printing at an affordable rate (enclosure prices elsewhere have generally been exorbitant, or require that I do all the machining / graphical work by hand). I want to check that this is safe and ask what precautions I should take before designing my project around this process.
Is aluminum safe? If so, should I ground the chassis? Are there other precautions that I need to be aware of?
The power input of my project is a 10A rated IEC socket, but I will likely fuse the project at 5A, in case that information is relevant.
Thanks!
ADC <->Arduino微连接:
我的ADC和Arduino微之间的连接是否正确，以SPI协议通信?< / p >
In Arduino IDE, how can I edit the code so that the Arduino Micro receives data from the ADC by SPI protocol and displays it in the serial monitor?
#include <SPI.h>
void setup() {
pinMode(SS, OUTPUT); pinMode(MISO, OUTPUT); digitalWrite(SS,HIGH); Serial.begin(115200); }
void loop() { byte c;
digitalWrite(SS,LOW);
Serial.println(analogRead(MISO)); digitalWrite(SS, HIGH); delay(100); }
我正在设计一个带有一些叶片的变压器，我有EI，我对二级电流有疑问。程序中我用,他为每个线圈canculated AWG 15支持4线,和我要如何从一个线圈连接到其他中心抽头,有必要使用AWG例如12或者代替AWG 15呢?< / p >
Print from the program I'm using:
Sorry for the ignorance, I've searched a lot about it, it seems silly to ask but I really wanted to know more about it.
我很困惑PWM信号在直流电机、LED和电阻器中究竟是如何工作的。
我正在试验一个MDB设备。我有一个简单的设置，有一个MDB主机和我自己的NXP EVK板作为从机。
我从一个逻辑分析仪开始，以验证我看到了总线上的通信。在下图中，我可以看到主机正在轮询。
我必须更改通道分析器中的某些设置才能读取此内容。
0Transition J K 0 0 |0 x 0 1 |1 x 1 0 |x 1 1 |x 0 是对的吗?它是数字0,1,2,3,4,5,6,0..
control1 == 0;control == 1 or control == 1 &Control2 == 0它不工作。< / p >I have measured voltage on NPN amplifiers which emitters are connected to driving transistors bases and it is high on both control lines in both cases (control1 == 0 && control2 == 1 or control1 == 1 && control2 == 0). This behaviour blocks circuit function as when both control lines are high it will not work.
Please any ideas what is wrong with that?
Even some DJ mixers using the SSM2164 simply joined outputs followed by an opamp. The same thing always happens - the amplitude gets bigger after combining 2 or more signals.
Then I found this question.
I have read a little on the LM3900 and the application note, page 41, not sure about that one.
The guy mentioned something about using current instead of voltage, so I figured, let's try with an LM13700, since they output current.
The same thing still happens: remove one of the 1 ohm resistors in the summing bus and the amplitude drops to to 50%.
Link to simulated circuit @ falstad
Does a (simple) fix exist for this, while keeping the LM3700, not using microcontrollers?
The inputs are 5 V.p.p., directly followed by a 100K pot, before the 100K resistors.
(I didn't do the AC coupling so far.)
我计划在STM32 Bluepill上实现电流检测功能，使用LM358单电源运放和0.01欧姆分流来测量太阳能电池板的电流输出(150 mA短路电流，14 V开路电压)。然而，无论我如何尝试，我总是得到一个不准确的输出值(远远大于预期，0.7 V低于正轨)。< / p >
That led me to the conclusion that the issue might be caused by the difference between the ground voltage of the op-amp and the measuring loop (schematic below). This made me question whether it was even possible to measure current across such a low resistance shunt using a differential amplifier, or if something else is causing my circuit to act unpredictably.
It is important to note that the resistance between the breadboard pins I am using is 0.07 ohms which is probably the culprit here; in addition, when measuring the voltage on the input pins of the op amp with respect to op-amp ground (the pin itself) I noticed that their values are different from the ones with respect to the ground of my power-supply, and the output seems to correspond to their values and not the ones I intend to amplify. In other words, there doesn't seem to be a problem with the gain of the amplifier, or at least as far as I know.
I would love to get some clarification on this, in order to decide whether to buy instrumentation amplifiers or not.
Note: I also saw people placing ceramic capacitors between the positive input and ground and between the output and ground in this configuration. I thought since the problem might be noise-related then it would probably fix this issue, but it didn't.
simulate this circuit – Schematic created using CircuitLab
在学习上拉/下拉电阻器时，经常会出现这个问题。人们为什么要问这个问题，很容易理解，这是一个合乎逻辑的问题。
如果下拉电阻器在逻辑高电压下被旁路，因为它不是电阻最小的路径，为什么它是电磁噪声的首选路径，导致；浮动；逻辑问题？
由于这是许多人都有过的问题，我将稍微澄清一下。对于我和那些提出问题的人来说，下面的两张图片，可以预测它们的行为是一样的。但是，很明显，他们没有。在断路开关电路中，电压逐渐消失，不会触发逻辑高电压。但在封闭的一个，它并没有流失，读作；“1”
添加一些上下文。一个有意义的解释是，输入阻止电流的趋势取决于电流是来自所提供的电压，还是来自噪声。非常浅薄的一眼；阻抗；概念，说它确实因不同的因素而不同，而阻力则不一样，https://electronicsclub.info/impedance.htm。这是有道理的。如果这就是解释，那么很容易指出这一点。显然，这与电子只有在来自噪声时才更喜欢R1而不是其他路径有关。
这个问题问的是同样的问题，下拉电阻器在此电路中如何工作？，而这一个，了解下拉电阻器电流，这一个，下拉式菜单如何防止出现”；假1“；在pin？中，所有都在电气工程stackexchange上。我还看到很多人在YouTube上的下拉电阻器视频上问同样的问题，这里有一些来自同一视频的例子：
https://www.youtube.com/watch?v=BxA7qwmY9mg&lc=UgyDSh1Jjg88vbeXN6J4AaABAghttps://www.youtube.com/watch?v=BxA7qwmY9mg&lc=UghF0bf2xVUdpngCoAEC
https://www.youtube.com/watch?v=BxA7qwmY9mg&lc=ugwbubinkzgkqzusrfb4aaabag
所以这是人们常问的问题，很容易理解他们为什么问这个问题以及他们问什么问题。
我之所以问这个问题，是因为我不明白为什么当开关闭合时首选路径会改变方向
我对FPGA有点新，我试图设置SPI连接到我的Artyx- 7板(Basy-3)的闪存。问题是引脚C11是一个配置专用引脚，它提供时钟SPI以及。板文档说我需要在配置时钟结束后使用STARTUPE2实例化对该引脚的访问。不幸的是，我不知道从哪里找到并实例化那个STARTUPE2。
. . . . . . .我有一个水流量传感器，它使用一个带有霍尔传感器的转子(ATS177 SIP-3霍尔效应传感器闩锁)。问题是，在水流停止后，转子还会继续旋转一段时间。
在许多齐纳二极管数据表中，我看到在绝对最大额定值部分，它们不包括可应用于齐纳二极管的“最大电压”。如果施加的电压超过齐纳击穿电压，则电压将开始传导，并进入反向击穿区域。
数据表仅包括最大功耗、热损耗、，温度和最大正向电压信息。
我想了解齐纳二极管数据表中没有提供最大额定电压的原因。
我的问题：
如何找到齐纳二极管上可以施加的最大电压？我是否应该根据数据表中提供的最大功耗额定值反向计算最大齐纳电压？如果是这样，你能举个例子。
如果是晶体管/MOSFET，可以施加在其上的最大电压就是最大集电极-发射极/漏极-源极电压，对吗？
更新：
我正在开发一款无线设备，它由两个Varta CP 1654 A3锂离子3.7V 120mAh（支持2C充电）和保护电路模块组成，两个MCU可以处理锂离子CC/CV充电
我的无线设备由两个用电缆连接的耳塞组成，我不能用其他类型的电池。电路板上有一个保护电路模块（PCM），每个单元安装在每个耳塞（Varta推荐的PCM）中。
如果我错了，请纠正我，但在2*2C并联单元的快速充电似乎有问题，原因如下：
如果在充电过程中，单元a在单元B之前达到4.2V，电池B可能接收到危险电流>；2C如果PCM_A触发过充电，或者最终PCM_A和PCM_B都会阻止充电。
我的目标是在安全的情况下拥有尽可能快的充电设备，并且我有两个IC能够管理CC/CV充电，这一事实让我怀疑在连接设备时是否可以触发电池之间的开关（Vcharge可用）这样我就可以为每个电池单独管理2C快速充电：
我试图找到一个可以在两个电池之间充当开关的电路。起初我认为两个MOSFET并联，但体二极管会阻止我想要的使用。
逻辑表示设备是否有Vcharge可用
当没有电荷时，开关应该关闭，并且充电时使用笔。
我知道这是不寻常的，大多数设计使用单芯电池，而其他一些设计使用并联电池，但充电电流低于2*2C。请注意，我的问题不是修改我产品的设计，我只想知道是否有可能使用这种“开关”电路可以让我在快速充电时使用两个充电器，而不是在慢速充电时仅使用一个
全双工和双单工的区别是什么？我真的分不清两者的区别。在全双工中，数据可以在两个通道中同时交换，而在双单工中，一次只能交换一个吗？
PCI Express在其3.0规范中描述为；双单纯形
我正试图设计一个振荡器电路，它能产生一个频率至少为500兆赫、振荡电压约为10-15伏的良好正弦波。这个振荡器的输出将连接到两个1平方英寸的导电板上（一个对集电极输出，另一个对地，两个极板之间有1英寸的间隙）。因此，电阻负载只是调谐电路的损耗。
我试图学习设计自己的振荡器，但在阅读数据表参数时，结果弄糊涂了，尤其是hfe（电流增益）各种BJT。
我被告知，为了获得500MHz，我需要一个过渡频率为5GHz的晶体管。我认为高于电路损耗的单位增益足以维持振荡。
我不明白的事情如下：
我绕了一圈。就像这张纸，
但它不起作用。
插入交流输入时，应显示方形波形。我不能很好地解释电路。
如果你知道什么，请回答我。谢谢你的阅读
例如:ATtiny2313的数据表(和大多数Atmel AVR数据表一样)声明:
128 Bytes In-System Programmable EEPROM Endurance: 100,000 Write/Erase Cycles
想象一个程序只需要两个字节来存储一些配置，其他的126字节实际上被浪费了。我担心的是，定期更新这两个配置字节可能会磨损设备的EEPROM并使其无用。整个设备将变得不可靠，因为在某个特定时刻，您无法跟踪EEPROM中哪些字节是不可靠的。< / p >
Is there a smart way to do wear leveling on a microcontroller's EEPROM when you effectively use only one or two bytes out of available 128?
