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Questions tagged [switch-mode-power-supply]

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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3
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1answer
759 views

Generating negative voltage rail using P7805 DC-DC converter

I need to create a negative voltage rail (from positive supply rail), say -5V to keep a P-MOS transistor in ON-state even when the voltage on its [S] source is 0V. So I found this schematic in an ...
0
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1answer
64 views

Power supply design, Pi filter

I am designing a power supply circuit. Does anyone have any calculation formulas for resistor which we connect across inductor or capacitor? I have attached a circuit with highlighting a connections ...
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1answer
41 views

Current Sensing Design

while using MCP1630 in switch mode power supply design, in the datasheet they gave the input bias current of the "current sense pin" what are the considerations the designer should take while ...
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0answers
50 views

Can a Capacitance Multiplier be used with high voltage outputs?

I am designing an SMPS which two output voltages of 5kV and 2.5kV. My transformer is split into four equal sections, each feeding a FB multiplier, connected in series to form the final voltages. ...
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1answer
16 views

LinkSwitch-XT2 (LNK3696) with opto feedback

What's a proper circuit if I want to use a LinkSwitch-XT2 device (from Power Integrations) with an opto coupler in the feedback loop? This is the typical application circuit of LinkSwitch-XT2 devices....
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1answer
43 views

micro water pump set up

I need to create a water pump system for a modeled water tank. Now I'm a complete noob so my ignorant self thought I could just buy a small DC pump, a switch and some connectors and off I'd go. Doing ...
0
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1answer
48 views

switch-mode power supply

First post here. I'm making a DC/DC converter which will generate an output of 19.5V 18A. Its a synchronous buck converter with the LM5145 TI chip. When I have light load on the converter the output ...
0
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1answer
69 views

Y cap between AC ground and DC ground in SMPS [duplicate]

I have seen in many SMPS there is a Y cap placed between AC ground and DC ground. What is the need of this Y cap?
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2answers
82 views

Eliminating oscillation in a feedback circuit

I have built a switch-mode power supply where the output voltage is controlled by a PWM signal from a microprocessor. The power supply is based on an XL4015. The feedback pin is normally fed by a ...
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0answers
41 views

Current mode boost converter design

I was trying to design a current mode boost converter in CCM using a MCP1630 and the specifications of the design are as follow: ...
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5answers
157 views

How can I describe and explain SMPS on a very basic level without diving down in heavy maths / EE lingo?

I'm writing a book about repairing electronics. The audience level for the book is "very little knowledge about electronics" and it's mostly about the mindset and mindtools for finding problem sources ...
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0answers
62 views

PFC boost converter is not stepping up the voltage

I am making a PFC circuit for AC-DC converter. I am facing a weird issue. As per my design the output of the circuit should be 390VDC, but I am getting 311VDCrms with ringing (overshoot 360V, ...
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1answer
51 views

Does supply voltage affects stepper motor driver heat dissipation?

Below is a block diagram of a stepper motor controller with an external mosfet h-bridge that drives one of the stepper's coils. Let's say that the coil has 2ohm DC resistance and 3mh inductance, the ...
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2answers
1k views

Why do oscilloscopes use SMPSes instead of linear power supplies?

I'm wondering why digital oscilloscopes are using switching power supplies instead of linear power supplies. The SMPS has a higher efficiency, but it can produce some noise during high frequency ...
2
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0answers
57 views

PCB design in class D amplifiers [closed]

in the process of building a class D amplifier I am now stuck at the point in which I have a lot of audible noise and I don't know where this is coming from. I know there could be a lot of causes but ...
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0answers
48 views

How to validate an SMPS transformer?

From UCC28950 webench design data I have approached a vendor for making a transformer for Phase shifted Full Bridge DC -DC converter. Now before giving order to vendor, I want to gather data on how to ...
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3answers
94 views

Transfer function of boost converter [closed]

When I have gone through some books I have found the expression of the DC Gain of the the boost converter in current mode is given by ...
0
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1answer
63 views

Is it possible to use an LDO as an Auxiliary source to a smps?

My SMPS controller can supply about 250mA and 3.3V output. There are rare but crucial moments when power demand goes above 250mA, voltage sags below 2.7V, and the MCU brown-out occurs. The ...
0
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0answers
31 views

Draw power evenly from two 12v battery banks, 24v solar system

I am currently running a small 24v emergency power solar system. I have a 40a MPPT charge controller with (4) 12v flooded lead-acid batteries in a 2S-2P configuration. I have a need for both 24v and ...
0
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1answer
82 views

TNY264 - hisses when isn't load significantly

Recently I designed a power supply based on TNY264 datasheet schematic and tested it. It works perfectly but at small loads the TNY generates a loud hissing sound. Only after load of about 100-...
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0answers
36 views

Driving a PWM controller with an SMPS - Does my motor like it?

SMPS Power supply: MP 3800 I have a 12V brushed DC motor hooked up to a PWM controller. When I run the motor (all works as it should) however there is a lot of crackling noise coming from the PSU. ...
2
votes
1answer
242 views

Why is the output from this regulator not a constant DC?

I have built a link switch. The output is DC 5V but, when measured with an oscilloscope, itis not constant. Why does this happen? How do I get constant DC output? Any design problem? ...
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0answers
49 views

Flyback Converter Oscillator

I am posting a small circuit I have found in a commercial power supply. It is a flyback converter transforming AC mains into 12V DC. I am having trouble understanding how transistor T1 is actually ...
0
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2answers
119 views

What's destroying the MOSFET in my buck-boost converter?

I have currently wired up this inverting buck-boost converter circuit: However, when driving the input of the TC4420 with a 62.5kHz square wave with a 40% duty cycle, the power supply overcurrent ...
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0answers
51 views

Use Triac as SMPS to get DC voltage

I want n 12V 1A supply for a project. I want a transformer-less topology. I was reading and experimenting with readily available traic based dimmers. They use phase control to cut the input voltage ...
0
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1answer
76 views

Strategies for troubleshooting buck converter

I'm trying to troubleshoot a tps65261rhbr triple synchronous buck converter from 12V producing 1.8V, 3.3V and 5V. The 3.3V and 1.8V are stable and well-functioning but the 5V is not. An oscilloscope ...
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0answers
42 views

High Voltage Active Rectification using Silicon Carbide MOSFET

This is a purely theoretical question, please forgive me if I am being stupid. Synchronous rectification and secondary side control of DC/DC converters is very commonplace in low voltage, high ...
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4answers
157 views

Maximizing efficiency in synchronous boost converter

simulate this circuit – Schematic created using CircuitLab The aim is to design a synchronous boost converter using a microcontroller ATMega 2560 switching at 31.25 kHz. 5V PWM signal is fed ...
0
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0answers
41 views

Understanding Phase Shift Full Bridge DC-DC Converter

I am studying PSFB DC DC converter. I am a bit confused in understanding the topology. For reference of the functionality I am taking UCC28950 Controller IC's circuit, From TI which have provided in ...
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0answers
47 views

Questions regarding Gallium Nitride semiconductor devices in Switched Mode Power Supplies

I have a couple of questions regarding the use of Gallium Nitride MOSFET devices in a DC/DC converter design of mine. My topology is an LCC full bridge converter. My knowledge is not at expert level ...
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0answers
39 views

negative Vds in SMPS!

Hi, I am designed a full bridge SMPS, like the above schematic. But when I measure the switch node voltage (I put voltage probe across Q2), I see when the mosfet is on, the voltage across it is -1 ...
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3answers
80 views

LDO vs Switching Voltage Regulator for Drone Application

I have been designing a drone flight controller and currently have been using LDOs to regulate the voltage to 5V. As I have started to use higher voltage batteries the LDOs have started to overheat. ...
0
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1answer
47 views

Protecting MAX485 data or supply from shorting to 24v DC supply

I have 2000 infrared proximity sensors along 100 meters, divided to 2 meter sections with an arduino reading them sending results by MAX485. For the power, I am supplying same 24v dc from each end of ...
0
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0answers
121 views

Does a PC need pure sine wave? Need to test using 1000W, 120VAC 60HZ input, 240VAC 50HZ output

I need an OTS (Off The Shelf) solution to test PCs before they ship to Europe and beyond. I need to provide up to 1000W of 240vDC 50Hz power from a 120vAC 60Hz outlet, because I want to make sure the (...
0
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2answers
99 views

My Buck-Boost Converter Circuit Isn't Working

I am currently working on a heated glove project using a Buck-Boost converter to adjust the temperature of the glove. I'm using the LTC3112EDHD#TRPBF QFN Buck-Boost IC to control the Buck-Boost ...
1
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0answers
57 views

Can MIC4102 be used to drive Boost Converter

I'm trying to design a high-power Buck-Boost converter, which is meant to convert a 45-63V input voltage into a "constant" 48V. The application requires quite high currents (up to 20A continuous). The ...
0
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1answer
77 views

H bridge inverter

I am trying out an H-Bridge inverter using GaN FETs at 140 kHz. The schematic is as follows. (In the experimental prototype, I used TI's LMG5200 and the load is connected via a full-bridge rectifier. ...
0
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0answers
43 views

Phase margin Vs damping ratio: Intutive explanation

While designing the compensator for SMPS we always talk about the relation between phase margin and damping factor( or Quality factor). I don't completely understand how damping plays such a keyrole ...
1
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2answers
153 views

How to find the right smoothing capacitor for rectification circuit

I am creating a power supply which will need to convert the 24vac to 5vdc. I am thinking of using a rectifier to convert ac to dc, then a capacitor to smooth out the voltage, then an LM2596-5 to drop ...
1
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2answers
275 views

ATX Power Supply Minimum Load

I know this is a commonly asked question but most of the answers I got are more than 5 years ago. So basically, My friend found a ATX power supply and was gonna give it to me. Since I already have a ...
0
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1answer
44 views

RC Snubber for synchronous MOSFET (SMPS)

I am trying to understand the theory of RC snubber for synchronous buck converters. Some statements seem to be contradictory to me in the below mentioned application notes: “The snubber capacitance ...
0
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1answer
39 views

Board mount AC/DC converter design concerns

I'm going to use board mount power supply (IRM-30-12) for first time. It has class 2 protections as per datasheet. Does it really protect my digital circuit in case of Hazardous situations like ...
0
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1answer
70 views

LED Strip - Voltage Drop when Wired in Parallel

please have a look at this chart: I have a question on the calculation of voltage drop on each of the connection point between the wire and led strip. We are using 1.5mm2 wire and 24V led strip which ...
0
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2answers
98 views

Why does this 5 V power supply work and the other one doesn't?

This is my first post here, I hope I'm in the correct area. This is my problem, I bought this circuit to receive caller ID over protocol DTMF. I have a few 5V power supplies here, (0.45A ,1A and 4....
0
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0answers
48 views

Output Current Derating for Buck converter for powering RF sampling data converters

I am new to the use of DC-DC converters. I am designing power supply for powering DAC from TI whose part number is DAC38RF80. DAC38RF80 is high speed RF sampling DAC with sampling rate as high as 9 ...
3
votes
1answer
109 views

Dielectric (HI-Pot Test) Failure on Ethernet Port

We have failure on Dielectric test between Power wire to Ethernet Port. Failure was observed near 1.7kV. After test Ethernet port was damaged (Phy chip). See attached Case 1 :- Where we apply High ...
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2answers
131 views

Can a typical switching power supply hold up for 10ms? [closed]

Can a typical switching power supply for 3D printers hold up for 10ms? (average relay bounce time) The printer draws 5amp@220 volt when heating the bed and the nozzles The printer draws 5amp only ...
0
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1answer
58 views

AC noise to electronic circuitry

I find some random issues that is still unknown. I'm using mean well SMPS 12v, 3A for supply and charging 2 cell battery 7.4v with a charging current 1.2A. The supplies are parallel which is switched ...
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2answers
110 views

Design of a low cost/low power Isolated AC/DC SMPS

I am looking to replace a classic 50Hz transformer/rectifier circuit with an SMPS. The input is to be 230VAC (EU) compliant and the output should be 5V/0.2A minimum while 5V/0.5A is a nice to have. ...
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1answer
32 views

Voltage cut-off in FDC6331L

I've prepared a circuit which allows to cut out the voltage. It is based on an FDC6331L IC. My circuit is as follows: E_GPA6 is an I/O pin from an MCP23017 ...