Questions tagged [capacitive-coupling]
The capacitive-coupling tag has no summary.
19 questions
4
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Shower tray acting as capacitor? Measured 28 V!
I'm hoping someone here might be able to give me a good technical theory (aware without more points of data a true explanation might not be possible) to explain the phenomenon I have experienced ...
0
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0
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Custom design for touch sensor with hole at center
I'm facing a quite hard task for my knowledge. I need to design a matrix for capacitive touch sensors with a LED at center.
The touch controller is a AT42QT2640-AU that has the following limits:
I'm ...
- 1,593
5
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2
answers
709
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Explanation for one of the signals on capacitive coupling in The Art of Electronics
I’m having trouble understanding the second signal in Figure 1.45
The book states that “…typical of what you might see when you look at a square wave, but have a broken connection somewhere, usually ...
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6
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6
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What's the point of putting a resistor here?
If we only want the voltage potential \$v_0\$, what can go wrong by removing \$R_L\$?
source of image: https://www.youtube.com/watch?v=rq7dmkcSco0&pp=...
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1
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Non contact AC voltage detector circuit current calculation
This seems to be a common circuit for a non-contact AC voltage detector:
Non-Contact AC Line Detector using BC547
The probe generates a small amount of current when it is near an AC line due to ...
0
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0
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126
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Contactless AC line detection using a single transistor
I have seen circuits that are used to detect the presence of AC voltage without any contact, like the one below.
Non-Contact AC Line Detector using BC547
I have tested this circuit and it works fine.
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1
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1
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496
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Detecting 220vac with optocoupler and microcontroller on lines that have capacitive coupling voltages
I'm a hobbyist, trying to instrument my heating system so that I can control a three position valve. I have an ESP8266 integrated with a DRV8825 stepper motor controller, and a no-name Chinese 220vac ...
3
votes
1
answer
106
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Optimizing AC capacitor coupling for enhanced DC filtering
I need assistance in refining my AC capacitor coupling circuit to effectively filter the DC component of my input signal.
The circuit consists of a current generator, a 1 Ω resistor, and an AC ...
9
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4
answers
2k
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What is the "problem" with directly coupled amplifiers?
As in the title, my question is basically about understanding what is the "problem" with directly-coupled (below, I will use dc for "directly-coupled" and DC for "direct ...
- 1,259
5
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3
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705
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CE Amplifier problem
I am new to learning about electricity and I was trying to make a common emitter amplifier.
I did some research and I tried to make the circuit. The circuit amplified the signal but the signal was not ...
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0
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1
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Why isn’t my overdrive circuit working?
I have attached an image of an overdrive circuit that I have designed for a guitar pedal. I have built the circuit and it isn’t working and I wanted to find out if there were any obvious design flaws/...
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1
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2
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304
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Un-biasing transistors
To amplify small signals, NPN BJT must be operated such that Vb + VsigLowest must be greater than the voltage drop of Vbe (~0.7V).
How do we center the resulting voltage Vce around 0?
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4
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4
answers
635
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What went wrong with this class A amplifier design?
I was trying to build a normal class A amplifier, but no matter how hard I try, I cannot find the reason behind my output (blue line) being clipped at the negative cycle of the input (yellow line.)
...
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9
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6
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Why do we need R1 in a non-inverting op-amp?
I am quite new to learning op-amps.
What is the purpose of putting R1 there? Does this have any meaning in the design of a microphone amplifier?
I read about this from another answer, which says that ...
- 91
0
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1
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193
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Human body communication, magnetic vs capacitive coupling
I am reading a paper by Park and Mercier called Magnetic Human Body Communication (2015). They are looking into human body communication techniques and compare magnetic human body communication (mHBC) ...
- 388
1
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2
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896
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Implementation of a capacitive coupling circuit for power line communication (PLC)
Introduction:
Hello everyone, I just wanted to see if there is anyone out there who is familiar with power line communication technology that can help me figure out what is wrong with my LTSpice ...
- 21
1
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1
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561
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how does AC coupling eliminate the ground current problem between data source and destination in FPD_Link II I/F?
Reading about FPD-Link II in Wikipedia, I came across this statement for which I need clarification:
Because the signal is DC balanced the application can use AC coupling, which eliminates the ...
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4
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1
answer
313
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Coupling an AC signal to a HV DC bias with a capacitor and OpAmp
Is it reasonable to float an AC signal on top of a HV DC bias with a HV Capacitor and low input bias current OpAmp?
The idea is that a fixed frequency AC signal (~1V pk-pk) comes from the left, is ...
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2
votes
2
answers
343
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Capacitive coupling for common mode rejection?
I'm not finding any information on this method, so I'm thinking that I must be missing something.
I have a 5V single ended RRIO opamp that I need to measure BLDC motor current with. The motor is ...
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