All Questions
Tagged with smps or switch-mode-power-supply
3,228 questions
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Ferrite Core Losses calculate
I want to calculate the losses of a ferrite core. I don't want to rely on TDK limited charts and numbers.
Here Magnetics INC has a calculation with constant numbers which is very useful
I am looking ...
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127
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MOSFET Driver Circuit - Current and Waveforms
EXPLANATION
I have a question about the MOSFETs I marked in red in the MOSFET driver circuit whose circuit diagram I gave below.
As you can see, the M6 is P-channel, M4 is N-channel.
When Q17 conducts,...
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Help identifying PWM controller SMPS ICs and other
Can anyone help find a suitable replacement for the following IC?
I have a SMPS few boards SMPS with two different revisions.
IC size SOT23-6
One revision uses 61A51a or 61G52 this IC has:
pin 1 (...
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58
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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 ...
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43
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Replacement for TPS51217
I need a replacement for TPS51217. I don't have a spare one available. But I do have TPS51218. They are only different on pin 5.
How to use TPS51218 instead of TPS51217?
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1
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Help with understanding the frequency response of a simple error amplifier
I am trying to obtain the frequency response of an error amplifier I designed the circuit of which is shown on the left and the obtained frequency response in Simplis can be seen on the right.
I am ...
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1
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55
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Buck/boost inductor design calculation
I am designing a buck/boost converter with the following parameters:
Vin: 2.5 - 4.2 V
Vout: 3.3V
Iout Max: 1A
Fsw: 1250Khz (From Dtasheet Page 3)
Mine is a battery powered application.
The inductor ...
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47
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Running a wall wart at 24VAC
I'm working on a HVAC project and I need 6-30VDC to power a XY-J05 module. 24VAC is everywhere, but one side is also "common" and used as a reference for a DC measurement.
Anyway, after ...
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1
answer
53
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Switched mode PS2 power supply failure [closed]
I have this power supply coming from a japanese PS2:
Since I’m stupid, I plugged it into 220V, but this thing is designed for 100V only… the 4A/125V fuse popped out after a couple of seconds.
Since I’...
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SMPS schematic Review
I'm designing a homemade 12V 10A SMPS power supply. This is the third personal project that I'm doing before heading out to college (1st year btw). I created a schematic that's inspired by YouTuber ...
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Can anyone help me to identify an IC marked FSHT?
Can anybody help me identify this IC marked FSHT?
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58
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Multiple Voltages Output Powered by 3.7V single LiPo Battery
I'm not sure if this circuit design feasible, but i would like to have multiple voltages output coming from a single LiPo battery (3.7 - 4.2V). Initially the battery output to a switching DC-DC boost ...
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2
answers
54
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Fundamental question regarding the working of a PWM voltage mode controller in SMPS
I am trying to build a PWM controller as shown in the figure below. Considering the example that my input is 5V and output is 10V and I need a duty cycle of 50%.
Ref for image: https://i.sstatic.net/...
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Flyback converter small signal
I am studying the small-signal analysis of a flyback converter.
The reference paper is titled "Modeling and Control Design of a Current-Mode Controlled Flyback Converter with Optocoupler Feedback....
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Identify IC marked 'MABK S14B'
Does anyone identify this IC marked MABK S14B?
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57
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Forced CCM Buck Operation
I bit confused regarding ripple voltage comparison for forced CCM mode buck converter and asynchronous buck converter in DCM. Which case we will have higher ripple voltage?
Next question, when should ...
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Understanding primary current in half-bridge push-pull converter
I am currently investigating a half-bridge push-pull converter and I am struggling with understanding what I see on the oscilloscope. (And why it keeps blowing up).
So for the circuit, its as basic as ...
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Problem with data given for transformer design
I'm using STelectronics design tool for making a SMPS, you can check this link to design yours STelectronics Designer.
The problem is that with the given data of the transformer is not clear for me, I'...
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1
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71
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Adding an output to a SMPS transformer
I'm working on this SMPS circuit (recommended by STMicroelectronics). If you have any suggestions for improvement feel free to comment that.
As you can see, the output has 12.05V, but I want to add ...
- 155
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1
answer
101
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Feedback circuit with tl431 and optocoupler
I was examining the feedback circuit on a power board belonging to a machine and I roughly drew the circuit on the feedback side as follows.
This circuit board belongs to a very old device and ...
- 730
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What is the "Forward voltage drop of the ringback rectifier" in an impulse power supply IC?
I have been looking at various impulse power supply ICs and most of the ones that I've found (e.g. MC34063A: https://www.rcscomponents.kiev.ua/datasheets/MC34063A.pdf) require me to know a value of ...
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2
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497
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What is the difference between disabling chip with directly disconnect power and with enable pin?
Often in a chip, it contains a pin with the name Shutdown, Chip Enabled, Reset, or similar.
Compared to directly disconnecting the chip power to ground (VCC/VDD to zero), what is the difference?
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66
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Power Supply phase margin above 90°
I am designing a 24 V to 12 V buck converter (max 3.5 A load current) using Vishay SiC462 buck module with integrated FETs. The control mechanism is a voltage-mode constant-on-time regulator with a ...
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How offline switcher DK125 FeedBack voltage is related to switching frequency and current limit?
I am trying to understand how DK125 behaves in terms of output frequency, duty cycle and limiting current corresponding to the feedback voltage on the FB pin, I see the voltage on this pin is divided ...
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27
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LT8316 Multi-Output drop on 1 output under small load
I designed a Multi-Winding/Multi-Output Flyback to generate +40V and -225V. In my application, the outputs need to work in a flip-flop load, where only one output handles a variable load of 0 to 50W ...
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2
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76
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Is this flyback topology?
In below circuit transformer output is rectified and going to load.
Many smps circuits doesn't even have that L1 inductor. Where can I get more material to read on this?
source:
https://electrobuff....
- 1,358
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4
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435
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simple relay/zener based switching power supply
Is this a reasonable way to build a switching supply without using power transistors or other modern devices? One concern is that this might oscillate a lot. What might it be missing?
Here Vin > ...
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88
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Is it possible to connect batteries series and parallel together and dynamically switches to one another according to the desired outcome at low cost?
Is it feasible to connect batteries in both series and parallel configurations while dynamically switching between them based on specific requirements? A simple and cost-effective procedure could ...
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37
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Three Phase DCX LLC secondary side control
I want to design a Three Phase DCX LLC with an input of 400V and an output of 48V. The architecture is shown in the figure below. I have a few questions I’d like to ask everyone:
1 If the secondary ...
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Designing CCCV supply
This is a pretty broad question, but my knowledge go as far as constant voltage supplys design (not even SMPS). I'm doing some research to learn how to design an SMPS for charging batteries, but I can'...
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Control to output transfer function
I am trying to derive control to output transfer function of phase shift full bridge converter.
Applying small signal analysis, I reach to the point/schematic as shown in the picture below:
Document ...
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56
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Output LC filter transfer function
I was trying to construct small signal analysis for phase shift full bridge converter. Below is the point that I reach.
According to the document, the transfer function of the output filter is given ...
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3
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486
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Optocoupler vs PSR
I'm learning about the design of flyback converters and noticed that optocouplers are used more often for feedback rather than primary side regulation (PSR). I understand that PSR isn't as good for ...
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2
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285
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Do I cut holes in the pcb when using a Meanwell IRM-01-5?
I am making a project that uses a Meanwell IRM-01-5 module, which is a small SMPS in a self-contained module, which is through-hole soldered to the project's PCB. The module has several holes in the ...
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In wireless power transfer coil characterization what is the significance of resistance of the transmitter coil at resonance frequency
I am characterizing a wireless transfer coil with the help of this document from Omicron.
In page no no-7 you can see that they are finding the resistance of the coil at resonance and it's value is 9....
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3
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190
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Roast my schematic
Hobbyist here. As I'm self-taught and far from a daily designer, I'm curious about any input you might have regarding my newest creation:
My intention is to track the capacitance of whatever is ...
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163
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Phase shift full-bridge converter
During t3-t4, only Q3 is ON shown with black arrow.
On the bottom-right of the picture, primary voltage and primary coil current increases towards negative.
I don't understand how the primary ...
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62
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Buck double output stage LC filter
I am trying to design a buck with a double output stage filter like this one from this AN:
It is written from this AN the second output filter will have a negligeable effect on stability if the ...
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66
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Can anyone help me identify this PWM IC in an SMPS? Marking: 8522B 2231
While tracing the SMPS circuit of a 24V 2A board I found this IC which seems to be a PWM controller IC.
The part marking is 8522B 2231
Anyone familiar with the symbol or where I can get the datasheet?
- 1,358
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36
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Push-pull converter primary RMS current calculation
I would like to calculate the RMS value of the primary current for a CCM mode Push-Pull converter. If I am correct, this is equal to the current through the switching elements (e.g., NFETs). I have ...
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2
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274
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Current mode control vs Voltage mode control
I am confused about why we always make the outer (slower) loop a voltage control loop and the inner (faster) loop a current control loop in switched-mode power supplies? I read these links, but they ...
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2
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84
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How to limit max current in a constant voltage SMPS?
I have 5 V 10 A SMPS. Using this, I tried to charge a 3.2 V 10 Ah lithium cell.
But the current shot up to 16 A and got stuck there. The cell got very hot.
Is there any easy way to limit the current ...
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How do switch mode power supplies solve the half energy loss problem in the charging of a capacitor?
If we charge a capacitor C with a DC source of voltage V, the energy stored in the capacitor is ½CV² and the energy wasted in wires is also ½CV².
Many videos say that SMPS minimizes this cleverly by ...
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MOSFET gate charge, rise and fall time
The gate charge is selected from the datasheet of the MOSFET given in the application note of Texas instrument for phase shift full bridge converter.
I don't have any question regarding the charge ...
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1
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Looking for a Vicor power brick substitutes [closed]
Vicor has been a curse of mine; I've inherited many devices in various companies that use their Maxi/Micro family bricks. They have improved a lot over time, but the problem is, they are very hard to ...
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73
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Grounding of an AC-DC-AC circuit for use in providing stable AC voltage for use internationally
I am hoping that someone can give me some guidance on a project I have been working on which has a single unresolved question.
For context to the question which I shall propose further on in this post,...
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1
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73
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Boost converter ground to ground noise issue
I’ve been working on a boost converter with all the control circuitries being controlled by a microcontroller. I am facing a huge problem of noise on the ground. I have all the grounds common and when ...
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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 ...
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PWM Switch models by C. Basso for LTSpice/QSpice [closed]
I am reading "SMPS SPICE simulations and practical design" by C. Basso, and I want to follow along with my own simulations. Are there any models of the PWM switches available for LTSpice or ...
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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 ...