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1500 questions
22
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2 answers

Half-wave diode rectifier - is textbook wrong?

I've noticed that in all resources on diodes and rectifiers, they show the output voltage as the positive half-wave of the input signal. However, that seems wrong. I understand that there's a voltage drop across the diode, and if the total voltage…
MightyPork
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7 answers

Do digital multimeters require calibration?

This article Understanding Digital Multimeter DMM Specifications / Specs mention A digital multimeter will only be able to meet its specifications when it is within a certain environment. Conditions such as temperature, humidity and the like will…
user275517
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3 answers

DC biasing audio signal

I have seen a few different ways of adding DC bias to an audio signal. I have simulated them and they all give me similar results, but I can't figure out why choose A over B or C. My audio source will be a Line Level Audio -2V to +2V AC passed…
jsolarski
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5 answers

Can FPGA out perform a multi-core PC?

I don't understand how FPGA can be used to accelerate an algorithm. Currently I'm running a time consuming real time algorithm on a quadcore laptop so that four computations can be done in parallel. I have been recently alerted that FPGA may yield…
Fraïssé
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22
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4 answers

What does a resistor do?

OK, very basic question here. I read lots of books, searched quite a bit, and every description I read seemed to talk about the flow of electrons and right away go too deep in theory for me to grasp the basic principle of their use. I understand a…
FMaz008
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2 answers

Why does ST recommend 100 nF decoupling capacitors for a 72 MHz MCU? (And not 10 nF.)

I've been reading about decoupling capacitors, and I can't seem to understand why ST recommends 100 nF decoupling capacitors on a 72 MHz ARM microcontroller. Usually 100 nF decoupling capacitors are only effective up to about 20-40 MHz due to…
Mike
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22
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9 answers

Why is the chassis used as ground in automotive electrical circuits

Automotive electronics generally use the metal chassis as the negative ground connector for the DC circuits. Obviously this saves something on wiring. Is there an electrical reason for this approach? (I am not asking why negative instead of…
bib
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22
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3 answers

What are those small metal bars going across a PCB for?

In quite a lot of PCBs that I have seen, they often have these small metal bars going across from one point to another. Here is an image of what I am talking about. In this example it is a charger: J2 and J3 are what I am talking about For…
George
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22
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4 answers

What protocol does a headphone jack use?

I have 2 questions. One is simple, the other may be not. 1. What's the official name for the standard headphone jack? It's universal for all brands of phones, so it must have a name (when you want to go shopping for components). 2. Is it using…
user3710
22
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5 answers

5 Band resistors and correct orientation

few days ago i bought few (about 500) resistors and i noticed that they have 5 color bands instead of 4. My question is how do i count them (which color is the tollerence) and how should i put them? Do they have a good or bad orientation like + or -…
Meletis Flevarakis
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22
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2 answers

Stm32 Event and interrupts

I started studying interrupts on stm32 specifically the stm32f4 discovery board. i found this example in which you have to press the button to start the interrupt and push it again to stop it. In this line:EXTI_InitStructure.EXTI_Mode =…
ChiPlusPlus
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How does a GPU/CPU communicate with a standard display output? (HDMI/DVI/etc)

I am interested in how the cpu/gpu presents (to whatever equipment that it does) video data after it has been processed. I have been told that the video is processed by the CPU/GPU and then sent to an integrated circuit by high speed serial that…
Craig Lafferty
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3 answers

"two bypass/decoupling capacitors" rule?

I found many discussions on bypass capacitors and their purpose. Usually, they come as a pair of 0.1uF and 10uF. Why does it have to be a pair? Does anyone have a good reference to a paper or an article, or could provide a good explanation? I wish…
Nazar
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3 answers

How to transform 5 V into 12 V?

I would like to transform 5 V 500 mA (from USB power) into 12 V with a few cheap components. Is this possible with the help of some generic parts (and not with the help of some expensive transformer, etc.)? Also, how many milliamps would this…
Matt
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3 answers

What actually is a shadow register?

I noticed the term Shadow Register while going through a datasheet of a TMS320F28335 DSP. What does it actually mean? Does it have a physical location in the CPU as the general purpose registers have?
noufal
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