Questions tagged [power-electronics]
Refers to the conversion of electric power by using solid state components such as semiconductors. Can also generally apply to the field of electrical engineering which works with power electronics.
3,195
questions
4
votes
2
answers
2k
views
Spark when connecting battery module to DC power supply
I am using a 60v DC power supply to charge a 48v battery module. I set current and voltage limits first, turn off the DC power supply, connect positive to battery's positive side. When I try to ...
4
votes
4
answers
755
views
GaN Vs SiC physic properties
Here is a table which shows the différence between GaN and SiC:
I have no knowledge about physics of components. I have just some bases. In the above table I do not see real difference between SiC ...
4
votes
4
answers
1k
views
GND pin of a RF device
I have a doubt about how to connect the following device (a RF power meter, AD8318) to the external circuitry. Let's consider the device:
There is the input RF coaxial cable, the power supply ...
4
votes
1
answer
13k
views
How much current does an 1602 LCD draw? [closed]
I want to know how much current a 16x2 (1602) LCD draws when the backlight is OFF and ON?
NB: My multimeter is broken.
4
votes
3
answers
1k
views
1117 Regulator input voltage
First, a little background -
I'm working on replacing an old (late 1970's) output driver board. The old equipment this came off of has a very dirty and poorly-regulated 5V system. Since I'm using ...
4
votes
5
answers
28k
views
What to plug in first to usb charger when charging: wall outlet or cell phone and why? [closed]
I asked this question on Physics StackExchange but was advised to ask it here.
When I charge me cell phone or notebook or whatever device what should I plug in first? Should I at first plug in usb ...
4
votes
1
answer
314
views
What kind of resistor is this symbol?
I'm looking at some power circuitry and trying to determine whether this is just a normal resistor with some extra nodes either side, or some kind of shunt resistor symbol or something?
4
votes
5
answers
30k
views
What is reactive Power and how it is generated and what is its source?
Many people, including me are good with dealing with real and reactive power in power flow systems, but still has question at the end of the day: What is reactive power and how it is generated or what ...
4
votes
2
answers
626
views
Why is my DC-DC buck converter consuming 8mA of current with no load connected?
I am using a TPS5430 buck converter on my PCB which is converting 12V to 8V. If I shutdown the buck converter using the enable pin it consumes only a few micro amps but if I leave it enabled with no ...
4
votes
6
answers
5k
views
Does output voltage of a boost converter depend on load current in CCM?
In the thread below, there are different opinions whether output voltage of a boost converter operating in continuous conduction mode (CCM) depends on load current or not.
Boost Converter Output ...
4
votes
4
answers
9k
views
Is supply current lower than output current in voltage regulator circuits?
Say I have a 5v linear voltage regulator circuit with a supply voltage of 24v.
If the 5v citcuit is using 20amps how many amps will the 24v supply need to deliver? Or will the current be the same?
4
votes
2
answers
226
views
Inductor - Voltage rating and Saturation
An inductor has rated operating voltage (across inductor) = 75 V. Suppose 100 V comes across it for some microseconds (~ less than 1 us). What will happen? Is the operation dangerous in such cases? I ...
4
votes
2
answers
1k
views
What's the purpose of the Zener diodes in this boost circuit?
I am looking at this boost converter for stepping up voltage to charge a Li-ion battery:
It looks like a standard boost topology, but I am new to this and am wondering: What is the purpose of the ...
4
votes
2
answers
887
views
Why does diode keep conducting even after voltage across it is negative
consider single phase two pulse semiconverter asymmetric configuration.
simulate this circuit – Schematic created using CircuitLab
Note the high value of inductance L1.
Let ...
4
votes
2
answers
1k
views
How to select DC-DC converter topology?
I would really appreciate some help on this one. I am doing my bachelor's thesis/project which requires me to design and construct a DC-DC converter. I have been working on it for a couple of weeks ...
4
votes
3
answers
823
views
Current Measurement. 50Amps 0.5% error margin
I am working on a solar energy project and I'm using a 10 panel array. For monitoring purposes I'm using a combiner device which tracks various data parameters like current, voltage and temperature. ...
4
votes
3
answers
2k
views
Push current source through transfromer
This lecture (from page 130) shows manipulation of the buck-boost converter model into canonical form.
I am stucked at moving current source through transformer as in the picture below or from the ...
4
votes
2
answers
2k
views
MOSFET in linear region
Can we work with a MOSFET only in the linear region? I want to use it as variable resistor so it can provide a fixed amount of current. The MOSFET SOA should not be violated.
4
votes
4
answers
2k
views
Accurately measure high quality factor coils
What would be the most suitable way to measure the quality factor of high-Q coils under the following conditions?
Specifications
Frequency: 5 MHz to 15 MHz, the target application is wireless ...
4
votes
1
answer
3k
views
What is 'Nonrepetitive Peak Surge Current' in diodes?
I just went through many datasheets of diodes but didn't understand the term "Nonrepetitive Peak Surge Current". Can someone please explain this to me?
4
votes
1
answer
2k
views
Is Inductive Kickback Protection not necessary for AC?
For DC inductive loads, typically a flyback diode is placed over the motor so that when the current changes instantaneously it doesn't have a chance to build upon the switch contact and then create a ...
4
votes
4
answers
1k
views
Is the Nyquist plot useful in actual electrical engineering?
I am currently doing a course on linear control theory, and we are covering Nyquist Plot to study phase and gain margin.
I find myself unable to appreciate this concept. One, the proof of the Nyquist ...
4
votes
2
answers
832
views
Thyristor SCR gate trigger
I'll work for the first time with a Hockey Puck type SCR with a high di/dt application. So far I've mounted it properly, with the proper clamp and heatsinks. Now I'm concerned with the gate drive, ...
4
votes
1
answer
551
views
Feedback in LM2574
I wonder what is the purpose of 'R66' at the feedback terminal of LM2574? I have seen its datasheet but I cannot find info about this. Instead of a single resistor there is a voltage divider shown in ...
4
votes
4
answers
2k
views
Phasor vs Vector vs Space Vector
I wonder what is the difference between a Phasor, a Vector and a Space Vector? A phasor is also a rotating vector in space then it means that a space vector is same as a phasor? Also by definition a ...
4
votes
2
answers
745
views
What is this ringing in the inductor current?
I am working on a buck-boost converter and I see this ringing in the inductor current. It happens on turn on of the high side FET (See attached Image). First of all is this ringing normal?
Is there ...
4
votes
2
answers
236
views
Equation 20.16 Proof
In studying the Fundamentals of power electronics by Robert Erickson I do not understand how they arrived at the equations for current and voltage
Link to Book, page 772 is where I am at
https://...
4
votes
2
answers
813
views
Mosfet gate driver have no direct connection to ground
This picture shows some part of a high frequency (about 250kHz) MOSFET gate driver circuit.I searched for various types of gate drivers in google and didn't encounter anything like this. Can someone ...
4
votes
5
answers
305
views
Dissipating Heat from Tiny Components
I need a 5v 2.5A output in a handheld device and have settled on the TPS61235P. Its 2.5mm QFN package was very hard to solder, but I finally got a board fabbed and tested it out. After roughly a few ...
4
votes
1
answer
60
views
What is meant by Switching charge ( under Gate charge characteristics) in the given MOSFET datasheet?
What is switching charge in this MOSFET datasheet?
The switching actually takes place during Miller region. Hence I belive Qgd should be called as switching charge. But looks like the remianing gate ...
4
votes
2
answers
140
views
Isolation Topology in SMPS
I have been researching SMPS designs as a hobby recently and finally have the courage to build one for theoretical and practical understanding. I have chosen an isolated design looking at several ...
4
votes
1
answer
2k
views
Overdriving LEDs with high currents
I'm trying to drive LEDs for the purposes of a strobe light. I'm planning on driving the LEDs at ~60 fps, and for ~100 us pulses to provide very sharp strobe images.
If the pulses are very short and ...
4
votes
2
answers
2k
views
LTspice Frequency Response Analyzer (FRA)
This post is a continuation of this question.
LTspice recently introduced a new feature called frequency response analyzer, see the image below.
The green box shows the symbol for FRA. If you click ...
4
votes
3
answers
6k
views
Reduce/Remove Sparks in AC and DC Contacts of Relays
I see that there are sparks being generated whenever there is a connection established between two contact points in the relays. So is there a way to reduce/remove those spark generated in the relays.
4
votes
2
answers
1k
views
Quarter-wave impedance transformer working principle
consider the following scheme:
A transmission line of length lambda/4 has been put before the load ZL in order to get an impedance matching. But, I do not understand how it works. Precisely, by the ...
4
votes
1
answer
287
views
What is the current component at the input of dc-dc converters?
The table below describles state space analysis in the field of power electronics. It is from a paper entitled "Signal Flow Graph in Loop Gain Analysis of
DC–DC PWM CCM Switching Converters by Wing-...
4
votes
3
answers
600
views
Where should I look for transformer inductance discrepancy?
I'm experimenting with this smallish (~15VA) toroidal line transformer as
a "lab" exercise as I'm learning about transformers. Right now it has its
original 115V primary winding only; I "unwound" and ...
4
votes
1
answer
432
views
High Voltage Power Supply Design
I need to charge a 1000uF 400V capacitor bank off of a 7V LiPo battery within roughly 5 seconds, and have the circuit be as small and light weight as possible. With a constant voltage supply and a ...
4
votes
3
answers
6k
views
Voltage divider Biasing of transistor
In this amplifier circuit we are using a voltage divider bias. Why can we consider that voltage produced by R2 is actually providing voltage to the base. What is R1 doing?
4
votes
1
answer
119
views
Push-Pull DC converter - resonance in the waveform
I'm building 48v to 200v Push-Pull DC converter.
And now I'm close to finishing the project, but when I checked the waveform on the transformer I discovered that it looks like this:
(on this picture ...
4
votes
1
answer
452
views
Why do wide band gap semiconductors allow for higher electron mobilities?
Other than increased energy handling capabilities, one of the main advantages of using wide band-gap semiconductors like SiC or GaN in power electronics applications is that the switching frequency ...
4
votes
1
answer
286
views
Turning off a MOSFET
What is the advantage of turning off a MOSFET on negative gate to source biased voltage of 5V instead of 0V? I saw that it is a very common phenomenon in SiC MOSFET as their datasheet always specifies ...
4
votes
1
answer
5k
views
Current spikes when MOSFET turns on and voltage spikes when MOSFET turns off
I studying for my Power Electronics course and have come across something which I can't seem to wrap my head around.
In a lab, we built a buck converter with an inductive load and measured various ...
4
votes
1
answer
90
views
PV Microinverter Topology Explanation
Can anyone explain how this topology works and/or point me to any literature where it is discussed?
I've found Microchip's application notes on single stage interleaved flybacks with SCR or MOSFET ...
4
votes
1
answer
461
views
What is high-side bias in a MOSFET gate driver IC and why is it needed?
I'm using the IR2104 gate driver in a DC motor driver design, and I noticed something in functional block diagram from the datasheet that I didn't understand.
The low side schematic is as expected, ...
4
votes
1
answer
1k
views
How to transform the line voltages to the phase voltages in control software?
Let's say I am measuring line voltages of the three phase grid 400V/50Hz via three instrument transformers whose secondary windings are connected to the adc of my microcontroller i.e. I have following ...
4
votes
3
answers
606
views
My Coilgun Stage Driver Keeps Burning Out Mosfets. Any idea why?
Here's my stage driver circuit:
The circuit worked as expected at around 100v. But at 330, both mosfets burned out at the first firing, and the entire cap bank discharged through the coil. I thought ...
4
votes
4
answers
12k
views
Current sensor measuring circuit
I am planning to design Rshunt basis current measuring. My current measuring range is 1A~2A. I need analog output of 0~5V analog with 1% accuracy. How can I do this?
I found conversion circuit here. ...
4
votes
1
answer
319
views
Power converter: Why is audio susceptibility named so?
In power converter, audio susceptibility refers to line-to-output transfer function. ( Line= Input voltage ) [ Ref : Fundamentals of Power electronics: Erickson ]
Why is it named so- "audio-...
4
votes
2
answers
837
views
Why do I get high DC current in grid tied inverter output?
Edit: Added gating signal waveforms. Changed some of the graphs, I accidentally put a test circuit waveforms the first time. Current is not that high but offset is there and current is high for a ...