All Questions
15 questions
0
votes
2
answers
446
views
Inductor in DC circuits
I've been studying about inductors lately, so I'm going to tell you how inductors work based on what I understood, please correct me if I'm wrong.
As soon as the switch is closed (in a DC circuit with ...
0
votes
0
answers
56
views
Question of Ethernet PoE and TVS protection [duplicate]
My question is based on this question over here
Asking this question here since I didn't receive a clear answer that clarified my confusions on TVS for PoE applications.
As far as I understand, the ...
- 945
0
votes
1
answer
146
views
Current amplitude of an Electrical Fast Transient
I am trying to build my own EFT generator as close as I can to (IEC 610000-4-4). In order to achieve that I need to figure out the parameters of the waveforms that need to be produced. I am at a stage ...
- 554
2
votes
1
answer
133
views
Avoiding spurious second order in a first-order RC circuit
While solving the simple RC circuit below in a particular way, I came across an interesting mathematical quirk.
simulate this circuit – Schematic created using CircuitLab
Using nodal analysis, ...
- 406
9
votes
4
answers
764
views
What is the physical model for energy flow in or around a lossless conductor during transient analysis? (Veritasium Electricity in Wires)
Context
Veritasium - The Big Misconception About Electricity - Energy Doesn't Flow in Wires
Note I do not agree with the answer (D) given by Veritasium which is only plausible if any tiny current ...
- 849
2
votes
2
answers
1k
views
Calculation of the capacitor value across the base and emitter to avoid unexpected turn ON of transistor
There is a design recommendation to add a capacitor across the base and emitter of Q2 to avoid the unwanted/unexpected turn ON of Q2.
Calculation of new capacitor across Vbe:
My questions :
Can ...
user220456
0
votes
1
answer
199
views
Transient current value
I am working on a SMPS and wanted to size a varistor at the input to protect the rectifier against transient overvoltage (let's say a 1 ms surge).
However, by looking at datasheets the maximum ...
- 505
2
votes
2
answers
237
views
Transient solution of current in circuit with two coupled inductors, with resistances
Circuit in question is given below. I want to find why I can not get the
same current waveform as PSpice gives me.
Basically I want to calculate formula for i1(t) by hand and get something as close ...
- 41
0
votes
2
answers
106
views
Why is the current for \$i(t)\$ \$5mA\$, not \$5e^{-\frac{t}{0.8m}}\$ mA?
Close the switch of the circuit, and it is in the steady state. We open the switch at \$t=t_1\$ suddenly. What is the value of \$i(t_1)\$?
simulate this circuit – Schematic created using ...
- 551
1
vote
1
answer
400
views
ESP32: Power rail transient when using SPI on battery
Working on a small datalogger project using an ESP32-WROOOM that involves an analog sensor signal being recorded and saved to SD card. Having a big power rail spike issue that has been isolated down ...
- 11
0
votes
1
answer
183
views
Inrush current and number of devices per MCB
I'm looking at some LED drivers meant to be powered by the regular mains voltage (230V). The datasheet specifies how many drivers can be connected to a single Miniature Circuit Breaker (MCB) on ...
0
votes
1
answer
162
views
Trying to understand the transient current equation on a RLC circuit
I am reading this doc
I see this magic happening on the third line of equations...
How in the name of Math, does this
\$ Ae^{st} \$
appeared there?
Magic?
- 847
2
votes
1
answer
1k
views
Find inductor current with Laplace
I need to find the inductor current for t > 0 and initial conditions as in example below. I think it's enough to divide V1 by 5*s and take the inverse Laplace Transform but my answer 3*e^-2*t - 7*e^-t ...
- 385
0
votes
2
answers
563
views
How to protect current sense IC from current transients
I'm planning to use a ACS712 current sense IC to sense motor-current in a project:
http://www.allegromicro.com/~/Media/Files/Datasheets/ACS712-Datasheet.ashx
The device I'm building uses a relay to ...
- 1,024
5
votes
2
answers
1k
views
Transformer current peaks
So I am designing a power supply, got everything calculated, and decided to simulate it for a second to see if the smoothing caps keep the voltage above the regulator limit at max current draw. What I ...
- 403