A switch-mode power supply (SMPS) switches been fully-on and fully-off states quickly to maintain voltage regulation. They offer lower power dissipation and run cooler than linear regulators that continually dissipate power through a transistor.

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29 views

Voltage regulator bypass capacitor placement

At both the input and output (especially the output), I need to place several bypass capacitors (all MLCC). The datasheet for the voltage regulator seems to suggest that using a 10uF on both the ...
5
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2answers
411 views

Is “catch diode” the correct term to use in SMPS context?

UPDATE: Ok, two good answers, I've chosen the one with more votes as the "right" answer, leaving it to the wisdom of crowds to choose between two fine choices. For anyone who cares, I think I'll ...
3
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1answer
56 views

Step-up converter for 20 mV input

For an experimental thermo-electric generator (TEG), developed by a colleague for low-power energy harvesting, it is possible to achieve an output power of 400 uW at the maximum power point. The ...
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1answer
104 views

What is the principle of operation of this power supply?

I bought this power supply off Amazon, it is described as 5 Volts DC 60 ampere. I was able to adjust the output so it produces 5 volts at its terminals. Here is a link to where I purchaed it from: ...
9
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3answers
216 views

What causes this knee in my MOSFET drain voltage drop?

FINAL UPDATE: Understand a previously mysterious power MOSFET switching waveform wiggle! @Mario uncovered the root cause here below, distinctive to so-called VDMOS devices, typical of many power ...
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1answer
34 views

Battery Charge and Discharge time for constant voltage charge battery, and how to know if its fully charged

In my Project I used below battery and a battery back SMPS. Battery Type:- Sealed Lead acid , Volt:- 12V, Ah:-7AH Charge parameters:- Constant voltage charge with voltage regulation Standby use 13.6V-...
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0answers
26 views

How to use Op-Amp circuitry to measure voltage across Power rail?

How to use Op-Amp circuitry to measure voltage across Power rail? I would like to measure or Make sure +18V external input supply is correct or not before enable switching +18V power to on board ...
2
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1answer
40 views

Efficient low current buck controller topology

In SMPS there are two sources of loss: parasitics, and the controller. Usually, the load consumes more power than the controller, and the parasitic losses dominate. I have the opposite situation. I ...
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2answers
63 views

Universal 3.3V & 5V power source for small device

I'm working on a hobby project which combines two modules that require 3.3V @ 130mA and 5V @ 100mA power sources. I want to make my device work at wide range of power sources - from single 3.7V ...
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3answers
76 views

What determines the output voltage of this SMPS?

This website http://danyk.cz/impulz4_en.html says that the output voltage is due to the zener diode that has a forward voltage drop of 18V. But zener diode is just a clipper that regulates the output ...
0
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1answer
33 views

CV or CC battery charging via SMPS module

I am using attached SMPS module, it has battery back up UPS function. I read the datasheet and I couldn't find information what type of battery charge scheme I need to use. Should I use constant ...
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3answers
90 views

switch off on 5v, on on 0v [closed]

i have a 2.4 tft lcd shield for arduino. I want to turn backlight off and to light it using the reset button from shield. This button outputs 5v when not pressed and 0v when pressed and led backlight ...
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2answers
58 views

What SMPS topology is this?

I came across this SMPS topology that I don't recognize. It looks sort of like a combination of a buck converter and a boost converter, but I can't quite figure it out. I haven't been able to find ...
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2answers
34 views

Considerations for switch mode power supply with microcontroller and sensors [closed]

I'm fairly new to this forum and the entire field of electrical engineering. I have a microcontroller (Atmega328P) project that includes a current sensor and several radios (900Mhz-2.4ghz). It is ...
0
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1answer
47 views

Modifying switching power supply to produce any voltage(s)

I have few units of 24V 3A output smps power bricks. I'm planning to mod one of this to generate 12V at least at 5A for my LED strips. My idea is to tap two wires from the secondary winding of the ...
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3answers
119 views

Two 12v Power supplies in series?

Is it possible to use my (3d printers 12V 20A power supply) in series with 12V unknown amperage pc power supply to gain at least 24V 20A for my printers new hotend?
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3answers
82 views

Does a switching supply always need load

I'm looking to use a switching supply from an old computer for a project. The project runs a motor that turns on and off based on a timer, powered by the switching supply. Do I run any risk running ...
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1answer
42 views

SMPS Short Circuit

I am using an ATX SMPS to power my Orange Pi Plus 2 via 5V supply. It worked fine for a couple of days without problem until yesterday. I happend to connect my audio amplifier TPA3116 which worked ...
1
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1answer
63 views

Battery Charger using a buck converter

I'm designing a Lead Acid battery charger with 3 stages. For the 2nd stage (constant voltage stage) as it is written in literature: the voltage applied on the battery must be dependent on temperature. ...
2
votes
1answer
62 views

How to stop leakage of mains adaptor [closed]

For the past year or so I have been using a mains to 5VDC adaptor to charge various devices. Everything is working perfectly fine but this charger I think, has a noticable leak to the low voltage side ...
4
votes
3answers
171 views

Benchtop power supply current limit on MC34063 switched-mode power supply

I'm currently building a power supply using a MC34063 IC. I have used an external n-channel MOSFET for switching the high current used to drive an LED pair. simulate this circuit – ...
0
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1answer
35 views

LT3680 switcher output doesn't have regulation under no load

I have a switcher circuit based on LT3680. I implemented the typical circuit shown in the datasheet in a well laid out 4-layer PCB. However, I find that the input voltage is present at the output at ...
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1answer
44 views

Need help identifying power transistor 11SL60H

Hopefully someone can help me identify what these two transistor are. I believe they're toast as the y open across all pins. Normally I can google parts like these but this one I get absolutely ...
3
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2answers
122 views

SMPS PCB Design Signal Integrity

This is going to start out like the other 53 pages of power supply questions "I'm a student working on a capstone project making an SMPS....". I have 12 months before the final design is due. I'm ...
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1answer
50 views

what's is the good frequency for switching mode power supply [closed]

What’s the good frequency of switching mode power supply to have good efficiency?
2
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1answer
73 views

Switch utilization in dc-dc converters

In the book, Power Electronics, by Need Mohan at the end of chapter 7, it is this image: Relating the output power and the power that the transistor is handling, I want to reproduce this plot for ...
3
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2answers
43 views

LC circuit of buck converter in nRF8001 datasheet

In the datasheet of the nRF8001, they specify in the reference schematic (page 51) the LC circuit to use with the integrated DC/DC converter (see below). Why is there a small inductor L5 in series ...
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3answers
54 views

TPS54231 input voltage sensitivity quite high?

I've spent this evening blowing up TPS54231s. Even a couple of TPS54331s. (note that C31 is currently DNP) The input voltage is specified as 17-24 VDC, and this circuit's worked admirably well at ...
8
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4answers
274 views

What is a flyback?

Trying to find this answer is so difficult that I can't even tell whether What is the difference between a transformer and a coupled inductor? is asking the same thing. Some reading suggests that a "...
0
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1answer
75 views

ZVS Driver design and initialization

I'm fascinated by zero voltage switching (ZVS) drivers. So I've been playing with simulations of them in Falstad. Two things I don't understand: How is the oscillation initiated in an actual ZVS? ...
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0answers
38 views

Constant power supply with high-voltage “restrike”

I'm still playing with electrolytic chemical reactors. After looking at the results from a constant-current circuit I'm realizing that what I really need is a constant power supply because, depending ...
0
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1answer
56 views

DC fan current requirements

Very basic question here that I thought I knew the answer to until last night, but now I am very confused. I picked up some 12v DC squirrel cage fans for a chassis I am building. Here is the Mouser ...
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3answers
82 views

Switch mode PSU minimum load

Alright, I know I am going to get a lot of flak for this, but let me reassure you that I have already spent the last few days reading on Google while going back and forth from the bench to test ...
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0answers
28 views

Switching power supply [duplicate]

I am currently working on a project of electronic being powered by DC power (7-40V) from car. The device is supposed to run properly (with several load of total 3-4A at 3.3V) when the car is turned on ...
3
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7answers
395 views

Role of Electrolytic Capacitors and whether they can be replaced by Film capacitors in battery operated power converters

In battery operated power converters such as motor controller ( half bridge or full bridge ) bulk capacitance is placed across Vdd and Gnd . I thought this was unnecessary since the input is DC and ...
1
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1answer
70 views

How to choose MLCC cap values for power supply decoupling?

I've read that it's best to use several MLCC caps with different values to filter out as much the varied frequency noise as possible. On the output of the voltage regulator, I see some noise in the ...
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votes
1answer
39 views

Specifications for a flyback transformer

I'm building an SMPS that takes in 110/220V AC and outputs +/- 3.3V DC. The chosen topology is flyback and as is the case of flyback transformers, I need to get one custom made. I have the Np:Ns and ...
0
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0answers
40 views

Oscilloscope builds charge on ground even when it is connected to mains ground

I have a following situation - my scope (UT4102C if that matters) builds some charge (quite painful to touch) on its ground (BNC connectors outer hull) even when it is connected via proper IEC cable ...
0
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0answers
55 views

Buck converter control

I'm using a buck converter to power a resistive load, the requeriment I've is to increase the current progressively, to do this I'm using a uC. Converter specifications are: Input voltage: 28V ...
4
votes
3answers
119 views

SIM900 Conducted Emissions Fail

I'm currently having trouble getting a product through EMC. Radiated emissions were comfortably under the limit, but conducted are failing badly. Here are the results: The noise appears to be ...
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2answers
50 views

SMPS voltage ripple

I'm using the MC34063 for my 35 VDC -> 4VDC SMPS. Here is the circuit (modelled in LTSpice): Edit: However, using a MC34063 calculator and setting Ipeak = 0.5A, L1 = 37 uH C3 = 12.5 uF Which, ...
3
votes
2answers
117 views

What R, C values to use in an RC Snubber to reduce output ringing in switching regulator?

I am using a simple buck switching converter (AP3211) to convert 5V-12V to 3.3V. The issue I am trying to resolve is the output ringing. I see a 800mV P-P ringing on the output, with a frequency of ...
0
votes
0answers
34 views

What are the risk of overload a inductor in buck converter?

I've a buck converter working at 100kHz simulate this circuit – Schematic created using CircuitLab So far I have tested the circuit for a 4A output current, but I may need to work with ...
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votes
2answers
70 views

Can i connect a dc power supply rated 20v,6 A to a system which needs a power supply of 8-32v and 1.5A? [duplicate]

Can i connect a dc power supply rated 20v,6 A to a system which needs a power supply of 8-32v and 1.5A? My concern is about current. Will my system only consume max of 1.5A from supply instead of 6A?
3
votes
2answers
126 views

How to keep a 9 volt micro-controller ON when where is no electricity for some minutes?

I want to keep an DCcduino clone of arduino uno ON where there is no electricity for 5-10 minutes with a 9 volt battery. Is there any way to do it without ups because it costs too much?
0
votes
2answers
182 views

Is my 600W boost broken or malfunctioning?

I'm asking this mainly as a sanity check and to distinguish between whether I've just done something wrong or need to buy a new one. I have a "600W" boost converter based on the UC3842A SMPS w/ CC ...
0
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2answers
53 views

Wiring a eTopxizu 12v 30a Dc Switching Power Supply to USA 240 volt plug?

I have a eTopxizu 12v 30a DC Universal Regulated Switching Power Supply. The power inputs are marked Ground-Neutral-Load. It has a switch on the side that adjusts it from 110 volts to 220. When I ...