All Questions
2,142 questions
-1
votes
1
answer
60
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Choke and MOSFET temperature relationship in VRM system
What is the temperature relationship between a choke and a MOSFET without heatsink in a typical motherboard VRM (Voltage Regulator Module)?
Context: I bought a dirt cheap CPU to extend the lifespan ...
- 131
0
votes
0
answers
57
views
Flyback transformer design
My question is almost similar to the question Google.
The flyback transformer is actually a coupled inductor. So it must be designed like an inductor.
After obtaining the required inductance, it is ...
1
vote
1
answer
66
views
Designing DC-DC buck converter based on the L6981 (L6981C50DR)
I will start by a small description of my system (I will omit any irrelevant information).
The DC DC buck converter that I am designing based on the L6981C50DR serves as the bridge between a smart ...
- 23
1
vote
0
answers
26
views
Analog auto balance bridge method for finding impedance of unknown
Hi all, I'm trying to find impedance of unknown (DUT - Inductor) with analog auto balance bridge method. I'm bit confuse about its working procedure, so need to know more about its working procedure. ...
- 21
0
votes
1
answer
31
views
Biasing circuit for MAR-8SM+ Amplifier
I'm struggling with the given circuit for the Mini-Circuits MAR-8SM+. The biasing circuit consists of Rbias(RES=260ohm), Cbias(HVC-0402,GRM43), and an RF Choke(TDK).
The Minimum voltage requirement ...
- 111
1
vote
1
answer
46
views
MOSFET driving external inductive load with high-side PTC protection and free wheeling diode
I intend to drive an inductive load across JP8 with a standard N-type MOSFET. We like to protect the high-side output with a PTC to guard against short-circuits, although our 12V supply is current-...
- 202
1
vote
1
answer
81
views
What is this transformer doing next to this piezo buzzer?
I'm looking at a few schematics that share the a similar circuit for the Piezo buzzer. The way that this buzzer is being driven is interesting to me. What I think is happening is that the MCU is ...
- 275
0
votes
1
answer
65
views
EMI filter design for a DC-DC converter
I am doing an EMI filter for a step down flyback DC - DC converter 20 V to (20 V and 10 V) multiple outputs. The controller used here is UC3842. I have the following questions for making this EMI ...
- 155
2
votes
1
answer
57
views
How to deal with low values of coupling coefficient in resonant circuits?
Im not a eletrical expert, so bear with me. Im trying to simulate a LC circuit coupled with a RL circuit, sweeping the frequency from 0 to a arbitrary number and observe the system's response when the ...
- 53
0
votes
2
answers
57
views
Not getting spark from ignition coil test circuit
I have a simple circuit setup with an N channel MOSFET switching ground to a two pin ignition coil. I am not getting any spark from the spark plug in the coil. Could someone take a look at the ...
0
votes
1
answer
120
views
How this circuit works? inductor amplifier
The inductors are to catch electromagnetic interference and then they get amplified by resistors R3 and R1? C3 is to remove any DC contents? How does it works and why from the first place a dc signal ...
0
votes
2
answers
48
views
inductive sin cos position sensor EMC considerations
I am studying the use of an linear inductive sensor of approximately 250mm movement.
Available IC's include TI LDC5072, Renesas IPS2550 and others.
Reference https://www.celeramotion.com/inductive-...
- 1,973
1
vote
1
answer
52
views
Would a voltage appear across the switch?
This is a situation of a de-energizing transient. My question is, would a voltage appear across the switch even in the presence of the discharge resistor \$R_{2}\$?
I am asking this because, I wanna ...
- 379
0
votes
1
answer
38
views
To determine the inductance on an LC series circuit. Why do I need to determine the lowest amplitude?
I recreated the following experiment to determine the inductance of a unknown inductor:
https://diyodemag.com/education/measuring_unknown_inductors_capacitors
I used Method 3. Where I build a LC ...
0
votes
1
answer
48
views
Determine inductive elements in transformer model
A model of a single phase, \$500 \text{V} / 6 \text{V} \$ two winding transformer, with an ideal transformer in the middle is seen below
simulate this circuit – Schematic created using ...
- 4,474
1
vote
1
answer
91
views
I can't identify the component if it's a resistor or axial inductor
I have an adapter (12v 2A) which is broken. i just face that component(indicated by the arrow) and didn't know if it's an axial inductor or a resistor.
I can't find the same colors in any color codes ...
- 113
0
votes
2
answers
122
views
Curve fitting a resonance Inductance graph
I need to do a curve fit for the graph below to be able to extrapolate the values in this formula: $$Z = \frac{R_s + j\omega L}{1 - \omega ^2 L C_p + j\omega R_s C_p}$$ Which is to say finding R_s and ...
5
votes
2
answers
556
views
Why a connection in parallel between a capacitor and an inductor is "violating" KCL?
I'm learning about impedance; I have a simple AC circuit (two resistors, one capacitor and one inductor):
The AC voltage is 10 V peak (7.07 RMS) at 240 Hz.
I calculated the equivalent/total impedance ...
2
votes
3
answers
272
views
Common mode choke DC resistance measurement technique
I am trying to measure common mode choke DC resistance to find out conduction loss due to DC current. I am using this (product link) one in particular. I measured the resistance between pin 3 and pin ...
- 43
1
vote
1
answer
56
views
Solar garden light inductor wattage?
I have a few solar garden lights that works and I wanted to increase its light output. I saw its circuit and it's using a IC YX8018 and looking at the circuit and datasheet I understand that the ...
- 712
0
votes
1
answer
80
views
Is it inductor?
When I disassembled the digital audio player, I accidentally damaged one of the components similar to the one I circled and this component is in series with the component I circled and is connected to ...
0
votes
0
answers
46
views
How can I derive these formulas?
For inductor design, I referred to this document, which states the following:
How are equations (17) and (18) derived?
What is Kc? Okay, I know it's the Crest ...
- 411
1
vote
2
answers
70
views
Selecting an Inductor for Boost Converter
I am trying to design a boost converter on my own, but I am having the following question.
I have searched for it, but I did not find a similar one. Sorry in advance if it is already posted.
The thing ...
- 11
7
votes
6
answers
1k
views
Transformer dot convention
If both input and output voltages are in phase, both dots will be shown up.
If the voltages are out of phase, the second dot will be shown down.
But how can the voltages be exactly in phase or exactly ...
- 1,358
0
votes
0
answers
51
views
Finding replacement for inductor that broke off my RTX 3090
I have the measurements as roughly 6.5mm x 6.7mm x 3.7mm (height)
I figure that a replacement can be purchased and attached, however I'm unsure which specific part to order. Can anyone assist with ...
-1
votes
1
answer
68
views
Inductor as an antenna circuit
I'm looking on that circuit: https://github.com/LOM-instruments/Elektrosluch-DIY
I try to understand what is the use of the inductor? I understands it used as kind of antenna(?) to pick up small ...
- 37
0
votes
0
answers
57
views
Would a pure iron core inductor be better for dampening capacitor bank startup current surge?
I was thinking and searching for how can a power converter handle power surges higher than its own sources limit. Particularly in two examples: buck converter that gives high current occasionally and ...
- 1,065
0
votes
1
answer
87
views
Why is filtered square wave output ~10% higher than half of peak voltage?
As we can see in the simulation, the voltage stabilizes at 550 volts instead of the expected 500. Why is that the case?
- 257
2
votes
3
answers
76
views
Why does the telegraphs equation not include inductance on the secondary path?
Apologies if I've missed something obvious, but when learning about the derivation for all the equations and behaviour with transmission lines, i noticed for example in the attached image, the bottom ...
- 701
14
votes
7
answers
2k
views
Can Inductors be thought of as storing voltage?
When I was comparing the capacitor and the inductor, I thought that just like a capacitor stores charge, an inductor ‘stores’ potential/voltage. I tried browsing the net to find out why I was wrong I ...
- 153
0
votes
1
answer
118
views
Why do LC filters with bigger inductors stabilize faster?
While trying out couple of values for an LC filter with a cutoff frequency of 10kHz I noticed that the configuration with the bigger inductor stabilized much faster than the one with the smaller ...
- 257
-1
votes
1
answer
46
views
What plays the stability of inductance value over frequency?
I made a measurement of inductance value over frequency and I got the curve as shown.
I see a high drop of inductance value at high frequency (over several kHz)
I don't really understand why the ...
0
votes
3
answers
74
views
Understanding non-ideal inductor model's \$R_{parallel}\$ resistor
I am looking at this paper, which shows a non-ideal inductor model:
I am not sure where Rp comes from. Rp suggests that the current can flow through the non-deal inductor element without going ...
- 3,620
1
vote
4
answers
324
views
Why is it said that inductor absorbs reactive power and capacitor delivers reactive power?
It is said that reactive power is that power that oscillates between the source and the load. The reactive power stored by an inductor or capacitor is supplied back to the source by it. So, since both ...
- 117
7
votes
3
answers
988
views
Why a minus sign is often put into the law of induction for an inductor
My question is only didactic:
I have been observing for a long time that students in particular always put a minus sign in front of the induction law:
u(t) = - L di(t)/dt
It is clear to me that there ...
- 584
3
votes
0
answers
91
views
Is this layout for the power section alright?
I’m working with two buck converters (LMR51430XFDDCR) and am currently designing their layout. I’m unsure if there are any potential issues with my current design. I am aiming for a PCB as small as ...
- 197
5
votes
1
answer
191
views
Strange current shape in joule thief
I am using a -26 core material toroid (yellow-white) (from China) in inverting joule thief.
The current at the top suddenly looses/decreases an amplitude.
A diode I am using is Fr102 so for 20 kHz it ...
- 2,853
1
vote
0
answers
28
views
Any way to increase the exitation frequency of this circuit?
I am working on the following exitation circuit for a fluxgate sensor:
The exitation circuit's purpose is to drive the coil (inductor on schematic) deep into saturation in both positive and negative ...
- 93
0
votes
0
answers
61
views
Personal Safety Alarm pcb board (via Piezo Buzzer) Question - missing inductor part
I’m working on a personal project, and I could really use some help. I’m not an electrical engineer, so I apologize in advance if this is a basic question, but I’m a bit stuck.
I paid someone to ...
0
votes
2
answers
84
views
Do wireless power transfer coils have polarity?
This question is a continuation of my previous topic.
I need to characterize this coil with the help of this document.
The coil will be connected to a BNC adapter and the other end of the cable is ...
- 3,061
1
vote
2
answers
169
views
Output voltage for synchronous buck converter and synchronous boost converter
I'm reading a book named The Art of Electronics, third edition. The book says:
Just to give a taste of some of the tricks that you can do with
inductors, take a look at Figure 1.52. Although we’ll ...
- 227
0
votes
3
answers
120
views
RL, DC circuit with a resistor in parallel
I've been revising for an upcoming exam and keep coming across this format of question, A coil with internal resistance N, is set in parallel with a resistor M, both in parallel with a voltage source ...
0
votes
1
answer
79
views
Properties of coils used in a power transmitter and receiver
I am completely new to wireless power transfer. I need to model a wireless power transfer link with the help of a Bode 100.
This is the reference document given to me.
Before starting this, I would ...
- 3,061
0
votes
0
answers
56
views
Question on switching for inductive loads
Quoting from "Sinalda - Inrush Currents | The Use of Static Voltage Stabilisers and Frequency Converters with Inductive Loads":
When you switch on an inductive load, there's a phenomenon ...
- 21
0
votes
1
answer
90
views
Measurement frequency for indicated coil inductance
This choke inductor has an inductance of 100 µH according to the website.
I know, however, that inductance varies with frequency (due to parasitics). So, I was wondering at which frequency was the ...
- 55
-1
votes
1
answer
47
views
Heising Modulation Reactor Inductance [closed]
I am trying to build a simple 5W tube Radio AM transmitter using Heising modulation. There is one thing I don't understand though. Does the inductance of the Heising reactor matter as long as it's ...
- 43
0
votes
3
answers
69
views
Why does the resonance peak dampen when an air cored coil is kept on a conducting material?
I was performing an experiment on an air cored coil, when I noticed that the resonance peak of the coil (Real(Z)) in air was sharp, but when kept on an SS316 plate, the peak dampened. When the coil ...
- 95
1
vote
5
answers
155
views
If the current through an inductor can't change suddenly, how it can induce voltage in the ignition coil of a car?
In an igniton coil, there is a voltage induced in the secondary when the switch is changed position. According to Lenz's law, the primary coil in the ignition coil will try to continue flowing the ...
- 99
1
vote
1
answer
84
views
Frequency of Oscillators
Greetings to the community,
Recently I have been tinkering with FM transmitters/receivers, and as such have become familiar with many different oscillatory circuits. One thing that stood out to me is ...
2
votes
2
answers
103
views
LED driver inductor heating
I have a LED driver based on AP3019, here's the schematics:
The LEDs its feeding are 4s2p white LCD backlight, rated 12V@40mA, the input voltage is 5V.
According to the datasheet, AP3019's switching ...
