Tagged Questions
11
votes
5answers
347 views
Why does a simple conductor start to emit EM waves when carrying a signal?
I understand that on circuit board traces with a clock, if the higher harmonics have sufficient power, it results in electromagnetic waves being emitted from the traces which creates EMI. What I don't ...
0
votes
2answers
75 views
PWM controller to meet EMI/EMC regulations
I'm designing an application in which the current running into a load is controlled by PWM.
A microcontroller generates a PWM cycle at 20kHz and this signal is used to control a MOSFET which is ...
1
vote
1answer
140 views
emi standards/best practices for PC cases
According to an EE friend, the FCC specifies EMI tolerances (max outputs) for PC components, including cases. However, here it says that there are standards for a number of components but not cases.
...
5
votes
5answers
288 views
Calculating resistance in decibel
In EMC there is an equation for charactristic impedance (If I am not wrong) that is defined as:
$$Z_w = \frac{E}{H}$$
As you know \$E\$ is expressed in Volts and \$H\$ as Ampers.
I had the exam ...
9
votes
1answer
918 views
How to shield microcontroller from electromagnetic interference
I'm working with high voltage circuit (2.1 kV for defibrillator capacitor testing) and I'm controlling power supply with arduino, reading required information from laptop using serial interface. Most ...
