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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EMI filtering at end of a long copper wire transmitting high DC power

I have a long (20 - 50 m) copper wire for supplying DC power. One one end there is a AC-DC converter supplying 600W-1000W of power at 60V output. At the other end I have a switching type (100-140 kHz) ...
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1answer
43 views

What the output isn't correct when I use a switching power supply?

I have a circuit that it is a STM32F103RET6(Reference Manual) board and one LCD. everything work very well just one thing! PWM! when I use my J-Link debugger to supply the circuit(or USB connector), ...
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61 views

Remotely control power supply with adjustable voltage

I have a power supply unit with adjustable output voltage. The output voltage is adjusted using a potentiometer. However, I need to change output voltage remotely and dynamically. What kind of ...
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1answer
45 views

How to MOSFET to drive 12v relay from microcontroller (logic high is 3.3V) using ZXMS6004FF

The above is part of my project design. 'BRAKE_CTL_3' is output pin from uController. It sends 0 or 1 to drive Q4 to turn it on or off. 'BRAKE_LSD_3' connect to one end of Relay. Other end of relay ...
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529 views

Converting cordless to corded: Pulsing issue

So I am rather new at electronics and electrical engineering. But here is what I am trying to do and what I need help with. Some years ago I had bought a cheap set of cordless power tools. Naturally ...
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4answers
140 views

Cheap switch-mode regulator “comparable” to LM317 [closed]

I've always appreciated the LM317 linear power supply regulator for being a sturdy workhorse. In particular, it's easy to build a simple regulator circuit which "just works" using an handful of ...
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2answers
24 views

SG6841 based SMPS output droops on load

I am repairing an Elo Touch monitor ET1515L which, happily, has dual mains and 12V inputs. It works when powered from 12V supply but struggles on mains. I see sets of capacitors for the PSU board ...
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58 views

Why do adapters fail when run on inverters? [closed]

It may be specific to my scenario, but I have brought more than a dozen adapters of varying voltages from different companies and all of them fail when powered through an inverter, after power is shut ...
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21 views

SMPS 85-265 Vac to 32 Vdc doesn't work for a long time

I'm developing a SMPS and I'm having some problems with heating. Firstly here is all information about the SMPS: Input: 85-265Vac Output: 32Vdc - 48W Flyback design IC: UC3842 Inductor size: EE28 ...
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1answer
25 views

How to properly ground chassis containing AC/DC switching power supply?

I'm planning to build a Digital Audio Converter as a hobby device and I had some questions regarding safely grounding the chassis. I want to purchase a power supply like this one: MicroMall(TM) ...
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3answers
69 views

What should the switch pin output of an SMPS look like on a scope

I'm continuing to troubleshoot a broken SMPS. At this point, I'm just trying to understand what components are broken, working under the assumption that it saw a voltage spike as a result of input ...
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1answer
38 views

Can a battery powered circuit experience input voltage overshoot on turn-on?

I'm trying to track down why my SMPS stopped working. One thing that caught my attention is this paragraph in the datasheet for the regulator: I'm using a 2700mAh 3S LiPo (rated at 35C, 70C peak) ...
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0answers
30 views

troubleshooting an SMPS

I've got an SMPS circuit that I put together around a TI TPS62125, configured to take 12V (a 3S LiPo) in, and produce ~3.3V. It worked. Everything was fine. Today, I go to turn on the system, and see ...
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13 views

Reprogrammable Remote Power Supply Raspberry Pi Monitor and Control

I currently have a reprogrammable power supply (HCS-3400) hooked up to be controlled remotely from an control/monitor app provided by the power supply company, Manson. The supply is connected via USB ...
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1answer
47 views

What type/topology of SMPS is this?

I'm researching designs for a simple bipolar output switching power supply and came across the design below in a ST datasheet for the MC34063A. However, there isn't enough information in the ...
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1answer
122 views

Resistor between Line and Neutral in SMPS

In Below SMPS Circuit ( Credit to:- NXP SMPS Design Tool ), in Red mark what is function of this resistor and why mid point of register is connected to Aux biasing of transformer. Thanks in ...
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58 views

MC34063 issue. Switches off every cycle

I am using MC34063 in step down configuration but the converter switches off every cycle. Following are the calculations and specifications: Vin - 9 to 12V Vout - 5V Imax - 0.3A Rsc - 0.36 ohms L - ...
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1answer
67 views

Why do wall plug power supplies use audible switching frequencies?

Every plug-in power supply ("wall wart") I have ever used starts off silent, but eventually starts to emit high frequency switching noise. It usually happens only when the charger is on, but not ...
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1answer
42 views

Switching and protecting batteries from external power supplies

my device can work from external power source as well as from two AA batteries, so voltage in this case is 3V, but external supply is 5v. I need to protect my circuit and power supplies in case of ...
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2answers
278 views

AC Power loss of inductor in a buck converter

I have a custom piece of equipment that gives a value for AC power loss (Pac) for an inductor plugged into an internal buck converter circuit. The custom equipment has an oscilloscope which is ...
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1answer
391 views

Will it hurt a non-powered power supply to see 12/24V on the output?

For an RC (mostly LiPo) battery charging setup I've got a 48V Meanwell AC->DC PSU supplying power to the charger. I'm considering simple ways to power the charger either by this PSU or directly by a ...
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3answers
126 views

Why does the MCP1650 datasheet give such a low value for the inductor in a boost converter?

I'm currently designing an SMPS around an MCP1650. In the datasheet (see page 4), the recommended value of inductor is 3.3uH. However, all the inductor size calculations I've come across (here and ...
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19 views

compare design discrete fet and pwm with FET integrated into PWM IC

Some new design of SMPS use the power FET integrated into PWM IC. Compared with discrete FET and PWM IC solution, what are the strong points and the weak points of the new design ? As your opinion, ...
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1answer
63 views

Why Some SMPS use Tiny Switch, Some use Top Switch and Some use Link Switch and Other use PWM IC. Please guide what is the criteria to select?

I saw many smps design , Some use Tiny Switch , Top Switch , Link Switch and other user PWM Control IC only. What is the difference and how to choose right one??
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1answer
36 views

low current buck converter

Just trying to find a suitable buck converter for my application, which is running off ~10-50V (12/24/48V battery banks) and supplying normally a very low load microcontroller (~1mA) but occasionally ...
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2answers
82 views

How to design a boost converter? And how to specify the inductor and capacitor values?

I want to design a boost converter with input of 48V and need to get to a voltage of 100V. How to select the inductor and capacitor values in it?
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40 views

Output Diode Snubber in Flyback Converter

I just completed making 48W flyback using TOP224. It is a fairly old Controller as well as its old design book. I looked at some of their modern ICs and design books and found out some significant ...
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3answers
34 views

Boost converter safety during debugging

When I was debugging my microcontroller-based boost SMPS I accidentally got 85V (instead of 15V as I intended) across the 1kΩ test load resistor. Does this spell a hazard for the one debugging the ...
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2answers
96 views

How to efficiently boost a low voltage high current input to a high voltage low current output

I have a 3.7V 6600 mAh lithium-ion battery that I'd like to use to power some small 6V motors that only require 500 mA. However, I need the battery supply to last as long as possible (which is why I'm ...
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2answers
190 views

What is dead time in DC-DC converters?

In a power management integrated circuit (PMIC) documentation I came across a programmable dead-time parameter for a DC-DC converter. What does ...
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0answers
51 views

How does temperature affect the performance of an SMPS?

I have an SMPS (laptop AC adapter) rated for 180 W that is presently operating at capacity. The output seems to be limited by internal resistance, but I can't really tell. I'm trying to get it ...
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58 views

Arduino UNO not working with L293D

I am creating a simple robot that is controlled by an Arduino UNO, and given instructions by a button matrix. One can press 4 buttons for Forward, Backward, Left and right on on the matrix array, ...
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75 views

Short circuit protection

I have built an AC/AC cuk converter for an assignment I am doing. It works as such, I provide 50V AC in and I get an adjustable voltage out from 0V to 50V AC, depending on the duty cycle of the PWM ...
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1answer
55 views

Switching between different batteries!

I Have got a project wherein I have to achieve this! Please neglect the charger set up for my block diagram. Since I am a newbie to electronics, I am unable to get any idea how I would switch ...
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1answer
37 views

isolated voltage

I am looking to add an isolated 10-12V supply capable of producing ~200mA to an existing circuit which has 5V and 12V rails available on the board. I would prefer to use the latter (12V) as it can ...
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56 views

Can a joule thief circuit be made to both boost or buck an input voltage?

In the normal run of things I would use a 555 or something similar to generate a PWM signal as the base for my power supply. The caveat is that for my application I need continuous operation from an ...
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0answers
96 views

Can I use a TVS diode to remove spikes in SMPS?

I have an almost working Half-Bridge SMPS that has some ringing in the output like this (not the real output, just and image I found): I have eliminated almost all the oscillation using a snubber ...
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36 views

Switching Power Supply Not Working TI TPS54331

Let me preface this by saying this is my first switching power supply design. With that said I used TI's online tool to auto generate the schematic / values of the resistors, caps etc.. What could ...
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1answer
63 views

12V -> 110V@0.11A DC/DC. what topology?

I need to design a step-up converter with following specs: vin = 12V +/- 10% vout = 110V iout = 0.11A non-isolated The most problematic constraint is that the converter must be very compact. ...
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3answers
118 views

Coiled Nichrome wire 220 volt

I want build a furnace using firebricks and coiled nichrome wire. The dimensions of the furnace are 1×1×1 m. I need temperature inside the furnace to be 650°c. I have 220 VAC mains. ...
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1answer
87 views

Can a CM choke be used to suppress common mode current in a DC circuit?

I have a setup with a DC/DC converter like in the figure below. I need to minimize common mode current on the supply input. There are no other connections besides Vsupply + and - and Rload + and -. ...
0
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0answers
24 views

What are the switching frequency and inductance implications of IEEE 519?

A simple power supply composed of a diode rectifier and filter caps has significant harmonic content. The line distortions caused by such equipment can have impact on other power utility customers and ...
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0answers
23 views

Unregulated Forward Converter for Galvanic Isolation

It seems to me that I could use an unregulated forward converter to provide galvanic isolation and then use a DC-DC converter to provide the voltage regulation. I'd use a two switch forward converter ...
2
votes
1answer
56 views

AP5002 step-down switching regulator loop stability

Problem, parameters I have an 5V output power supply, with 2S LiPo input (6-8.4V), implemented with AP5002 (PWM control 2A step-down switching regulator, docsheet), and for the life of me, I can't ...
21
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4answers
2k views

Spacecraft Power Supply Frequency

I know that aircraft sometimes employ a 400Hz AC system to save weight on transformers, so I'd imagine that spacecraft might employ a similar technique. I'm wondering if anyone in the aerospace field ...
2
votes
1answer
101 views

Choosing a linear regulator vs. switching regulator for low-power application?

I have a 3.6 V battery that I want to regulate down to 3.3 V and 1.8 V rails. I have already asked about the configuration of the two rails here. My question here however is whether I should use a ...
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2answers
63 views

Create a Time-Variable Dc Power Source

For some reason, I need a Time-Variable DC power source that changes it's value according to time. I need this changing of value to be controllable. I'll put it this way : Say I have a 12 volt DC ...
0
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1answer
106 views

Driving a low resistance load with PWM

I have been trying to build a simple PWM power supply to use a 3.7v battery to drive a small heating element with a DC resistance of about 1 ohm. I have built a slightly modified version of the ...
1
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2answers
65 views

Buck Converter vs plain PWM Power modulation

I have a dc load that I'll be controlling with a fixed voltage DC source. The output of the load is proportional to the average power delivered (it's a heating element). Since the element is a fixed ...
3
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3answers
93 views

MLCC as SMPS filter caps

This question is out of curiosity. I know fairly well that mains SMPS can suffer from bad electrolytic caps. Now I wonder if replacing all electrolytics with MLCCs work? Will it make a more durable ...