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1500 questions
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5 answers
Why did Axial Capacitors Fall Out of Use in the Industry?
When inspecting the boards from electronics made in 1980s and earlier, one distinct feature is the extensive use of axial, electrolytic capacitors as power supply filter. Axial ceramic decoupling capacitors were used as well, to a lesser extent.…
比尔盖子
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8 answers
What tools, equipment, and techniques do you use to solder fine-pitch SMT parts?
Possibly many questions have been asked on soldering smd parts, but I haven't found specific answers, Like:
Do you use a watchmakers lens or some other type of magnifying glass while soldering these miniature components? What would be most optimum…
Kevin Boyd
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For a lower voltage drop one could use Schottky diodes, but what are the disadvantages of Schottky's?
In other words, why don't we always use Schottky diodes if they are so much better? What diode properties do Schottky diodes have that makes them unfit for certain applications?
jippie
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44
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8 answers
USB Shield. To ground or not to ground?
I have been given a device at work to do some testing on. Basically an IC is becoming obsolete so I need to test a replacement part. Upon redoing the ESD checks, the device failed.
I checked the history of the device, and there were problems…
MCG
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5 answers
How do I design my very own ARM based processors?
I have several questions about how I would design my own ARM-based CPU?
How does one start with an ARM license and end up with a package ready to be soldered on to a board?
What do I get from ARM (I am sure they have multiple license options to…
Lord Loh.
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44
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4 answers
At what voltage is a NiMH battery empty?
I have a battery pack of NiMH batteries. It is ten cells with 1.2V, 4000mAh each, put together in series. So rated voltage is 12V. After charging, i.e. when the charging device says that it is finished, I measure 14.3V.
When I now discharge, at…
Till B
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6 answers
Why do CRTs have 3 electron guns?
I have been wondering about this for a while:
Since the phosphor will remain excited for a certain period of time, I could imagine a single electron gun could target the red, green and blue phosphors sequentially instead having 3 parallel…
Thomas
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44
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2 answers
What is the failure mode of a solar panel?
I have understood that solar panels don't last forever. Warranties are typically a couple dozen years, and you can expect your panel to last for perhaps twice the warranty period.
But what does exactly happen when the panel is failing? Does it fail…
juhist
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44
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8 answers
Why are car batteries still so heavy?
Back when I was a kid, car batteries used to be huge heavy lumps of plastic filled with lead and acid. They used to weigh almost as much as a mobile phone (slight exaggeration there, sorry).
45 years later, car batteries still look the same and…
user130311
44
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2 answers
Why do CPUs need so much current?
I know that a simple CPU (like Intel or AMD) can consume 45-140 W and that many CPUs operate at 1.2 V, 1.25 V, etc.
So, assuming a CPU operating at 1.25 V and having TDP of 80 W... it uses 64 Amps (a lot of amps).
Why does a CPU need more than 1 A…
Leonardo Bosquett
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5 answers
Is there an ideal PWM frequency for DC brush motors?
I'll be using a microcontroller to create a PWM signal for motor control. I understand how PWM and duty cycle works, however I am unsure about an ideal frequency. I do not have my motor in yet, so I can't just test it and find out.
The picture…
Nate San
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4 answers
What does edge triggered and level triggered mean?
I am studying 8085 microprocessor architecture and the terms edge triggered and level triggered confusing me really very much. Can anyone explain me it in layman's words ?
While studying the interrupts of 8085 named RST 7.5, RST 6.5, RST 5.5 and…
ATR
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3 answers
Switching DC with MOSFET: p-Channel or n-Channel; Low Side Load or High Side Load?
I think, it is time I understand working principle of MOSFET transistors...
Suppose that;
I want to switch voltage on a resistive load by a MOSFET transistor.
Any control signal between -500V and +500V can be easily generated.
The transistor…
hkBattousai
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44
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9 answers
What is the reverse recovery time in a diode?
What is the reverse recovery time in a diode?
Cell-o
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