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 disspate power through a transistor.

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65 views

What is the ideal way to handle data pins D+ and D- on a USB power adapter to be compatible with fast charging on devices?

I have found that many USB wall chargers use a resistive voltage divider to set the D+ and D- pins to a specific voltage, usually between 2 and 3 volts. Other USB wall chargers short the D+ and D- ...
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55 views

SMPS : Average Current Control Vs Peak Current Control

Please correct my understanding. I understand that in peak current control mode, the slow outer voltage control loop generates a current command to the faster inner current loop. This current command ...
3
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3answers
132 views

Why would the output voltage of a 5V SMPS (USB charger) increase with load?

I've been using a USB voltage/current measurement device to evaluate power consumption of USB devices and performance of USB chargers and batteries. Most of the USB power supplies I've used are ...
0
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1answer
27 views

Inductances in flyback transformer

I am simulating flyback dc-dc converter in multisim software tool .. I want to know the difference betweem primary inductance and magnetising inductance , also secondary leakage inductance?
0
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2answers
64 views

Can I power Ardiuno using buck converter IC 3485 or any other buck circuit?

A buck circuit lowers the voltage by generating pulses at a certain duty cycle. Is it okay to give this pulsing voltage to Arduino? Can Arduino work normally with this? I have 12V battery and I want ...
0
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1answer
88 views

Why is a resistor put before the gate of a transistor?

In most of the H-bridge driver circuits I've come across so far, there's a resistor in the path of the signal to the gate/base of the mosfets/BJTs, like in the images below why is it put there ? ...
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14 views

Noise in Inductor Current : Buck Converter [duplicate]

Source DC: 300v DC Output DC required : 160v DC Load Current : 7A DC Buck Converter Topology : IGBT as switch @ 8khz 1.1 mH Ferrite Core Inductor Measured Inductor Current ...
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2answers
170 views

High EMI PCB track under transistor or diode package

Can a high EMI PCB track under a transistor or diode package (in this case TO247AC) be a problem? To get a better understanding: Is there any advantage on putting these tracks on the other side ...
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3answers
95 views

Spikes in Inductor Current : Buck Converter

What could be the reason of such spikes in inductor current at each Switch ON-OFF. ?? This spikes are also getting affected in load current. Please help me to reduce / remove this spikes. ( ...
2
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1answer
183 views

LM3485 current limiter (\$R_{adj}\$) value selection

I have what I believe is a working buck converter design centered around the LM3485. It's intended to be a Raspberry Pi power supply. The schematic is at Pi Power schematic, which I copy below. ...
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2answers
59 views

Using triacs to switch more complex equipment than just motors and lights?

Obviously triacs have been well known to be used in applications which don't really require a perfect sine wave to function. However, what about say a triac to switch on and off more complicated ...
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2answers
55 views

Stray-inductance and capacitance of non-isolated heat-sink

I read an application-note that says the heat-sink (when not electrically isolated), is one of major source of EMI. Well I think this can be corrected at some point by good EMI filters and a good case ...
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2answers
59 views

Switching regulator PCB layout

I'm putting together a buck regulator (first time around) based on the lm2374 chip. TI provides gerbers of a recommended layout for this chip family, but my configuration differs a bit. I've read up ...
2
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2answers
208 views

What is a good power electronics textbook?

I really want to learn as much as I can about power electronics, switching mode power supplies, and overall analog design. Unfortunately my universities computer engineering program is still ...
1
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1answer
58 views

What is an auxillary winding in a flyback transformer?

I am researching about SMPS, specifically AC/DC flyback converters. In the datasheet for the switching controller (Fairchild FSCQ0765), it refers to an auxiliary winding. What is that? All the ...
2
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1answer
58 views

Catch diodes in switch mode power

I am wondering about catch diodes in the context of switching power supplies. I have read all the books that are the norm in designing a SMPS, but all of them don't or barely touch the subject. My ...
2
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1answer
62 views

calculating total power consumption with LDO vs switching regulator

I'm just getting somewhat familiar with voltage regulators and am trying to make sure I'm understanding a bunch of parameters correctly. Scenario: I have a project that spends 1/3 of its time ...
6
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3answers
385 views

Deciding capacitor value to use in my circuit

I have a power source which supplies 1A at 5V. I am using a switching regulator which supplies 1.3A at 3.3V. The load requires a burst of 2A without reducing the voltage across it than 3.2 V for 477 ...
0
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1answer
68 views

How can I modify the charging circuit of the solar powered system using super-capacitor with or without battery (diagram is attached)?

I 'm working on a device which according to the below diagram, has a solar panel witch gives at most 10v voltage and 30mA current (average 9v and 20mA) and also it has a 6v lead acid dry battery with ...
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0answers
25 views

Battery Charge Regulation Application

I'm building a switched mode power supply unit to take electrical energy generated by solar panels and store it inside a Lithium Ion battery pack. Some specifications: 1. The solar panel open circuit ...
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1answer
91 views

Switch mode power supply connected to the diesel generator makes bad voltage oscillation

GEKO diesel generator has 60 kVA electric power. Our switch mode power supply connected to this generator via passive filter DL-50EA3 and 6-pulse bridge rectifier (see the schematic). In this ...
3
votes
1answer
183 views

Assistance required to design a Powerbank

This is essentially a Q & A tutorial set - as provided for in SE rulez. I am trying to build a Power Bank* on my own. Can anyone assist me in designing a circuit or suggest ones which may form a ...
2
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4answers
299 views

How to make a step down DC-DC converter fail safe?

I'm planning to power some high power colored LEDs with a buck converter, using a microcontroller to control the switching to maintain a constant current. I'm also considering a simpler, switched ...
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1answer
76 views

SMPS input voltage

I find lots of SMPS, with a PWM current mode control IC in the input AC variation range of approx 1:3. From 85V AC ~ 265V AC at its input. Which parameter restricts this is it minimum 'Ton' possible? ...
0
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1answer
97 views

Switched-mode constant current supply with Schmitt Trigger

I'm planning on building a small constant current power supply for charging lithium-ion batteries on the go. While they normally use constant current AND constant voltage, I've elected not to include ...
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3answers
112 views

Power 4.5V Lego motor by 5V PSU, how?

It's a long story. Please bear with me as I try to describe what I intend to accomplish. I've got a Raspberry-PI controlled Lego Technics (pre-Mindstorms era stuff) construction. It uses a couple of ...
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0answers
44 views

How to add a desirable phase shift in the input from 3-phase ac mains?

I want to build a 12 pulse rectifier circuit. I know delta-wye or wye-delta transformers can be used to add phase shifts equal to the multiples of 30, but I don't want to use transformers. Is there ...
0
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2answers
109 views

Flyback SMPS Transformer choice

In several projects so far, I have been using old "fashioned" transformer based power supplies. However, this time around I want to use a switching mode power supply. The supply will be used to power ...
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2answers
70 views

300W Boost converter design

I am designing a boost converter. I know maybe the specs I want would suit better in another topology like Half-Bridge or Full-Bridge but the boost topology is simpler and inductor winding is simpler ...
0
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1answer
44 views

Multiple Voltage Switch Mode Power Supply

Building a multiple voltage power supply for an extremely harsh environment. Will be in a factory type environment with heavy equipment. Looking for a sanity check on the schematic and board and any ...
2
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2answers
202 views

Manual transformer winding - dots convention

I've already seen this and this. But I can't decide how to correctly wind a SMPS transformer. This is the transformer: I mantain the same turns direction (CCW if you look at transformer from the ...
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2answers
94 views

Fast rectifier diodes in parallel at SMPS

I'm trying to build a 35 V @ 10 A SMPS. I don't have 15A diode to rectify the transformer output. Can I use two BYW29 in parallel? They are rated at 8A. I know that when diodes are in parallel, the ...
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1answer
97 views

Switched Mode Power Supply : Voltage Mode Control and Error Amplifier Output

I am trying to understand how regulation happens on Cycle-Cycle basis in the case of Voltage Mode Control (VMC) and Current Mode Control (CMC). I understand that in the case of VMC, an error ...
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0answers
56 views

How to model Texas Instruments UCC28700?

I'm using Multisim in an attempt to simulate a flyback supply design reference by Texas Instruments that makes use of a voltage controller - the UCC28700. Multisim has no SPICE model natively nor does ...
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0answers
24 views

SMPS noise effects on External Serial Flash

As I was reviewing a schematic that contained an External Serial Flash part powered by a SMPS I found myself thinking about the risks of using an SMPS (that uses PFM and PWM modes) to power a serial ...
0
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1answer
56 views

How can I protect my SMPS feedback voltage divider from loading effects?

Background: I now have a working switched mode boost converter on a breadboard, working as a 12 Volt DC to 24 Volt DC converter. I was troubleshooting what looked like an output voltage problem when I ...
0
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1answer
92 views

Sharing negative terminal (“ground”) between 2 LiPo batteries and UBECs / paralleling 2S LiPo packs

One of my projects require a hefty amount of amperage - and as such I want to use 2 LiPo 2S batteries, in parallel. In addition, I am regulating the voltage using multiple DC-DC step down converters ...
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0answers
191 views

Bidirectional DC-DC converter, 12V - 300V, 1 kW?

What DC-DC converter topology would you recommend for a device that supports bidirectional power flow of up to 1kW with 300VDC on the high-side and 10-15VDC on the low-side? I want to use it to ...
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2answers
103 views

Power supply noise caused by external heat pad

I have a circuit that switches a 50W Sunbeam heating pad via a relay (for regulating temperature). My circuit is driven by a 5v AC/DC switching converter. The AC input to the power converter is shared ...
1
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1answer
57 views

Supply voltage of stepper motors

I'm going to use the following stepper motor drive chip: http://www.st.com/web/en/resource/technical/document/datasheet/CD00255075.pdf And I have choosen the following AC/DC converter: ...
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2answers
572 views

SMPS with two outputs ,12v 3A(max) , 24V 2A(max)

Hi all , I am new to designing circuits. I am building an SMPS using the fairchild Semi FSGM300N Power switch. here is the datasheet http://www.farnell.com/datasheets/1526530.pdf they have given a ...
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4answers
285 views

What makes the transformer in a SMPS smaller?

I'm reading up on how SMPS's work, and all the videos says that after the high-volrage chopping stage, a smaller transformer can now be used, because of this high frequency. My question is, how does ...
0
votes
1answer
92 views

Is it possible that LED power supply is interfering with my webcams USB connection?

Not sure it is a right place to ask this question but I'm pretty out of options. I'm building DIY home-studio LED lights out of multiple 12V LED bulbs. I'm using a dedicated power supply connected to ...
1
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1answer
141 views

How does the PWM from MCU get translated into a output voltage as in Power Electronics [closed]

Background: I am preparing for a full-time employment starting in May. I am coming from a computer engineering background so I only have some working knowledge regarding EE. The job duty is Firmware ...
1
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1answer
130 views

SMPS --> TDA8920 | +V GND -V op-amp

I'm thinking about buying a TDA8920 audio amplifier and power supply and I need some help buying the right PSU. See edit below. So here's what I know. L (AC) = Live (Brown*) N (AC) = Neutral (Blue*) ...
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0answers
68 views

Why does this voltage error amplifier output always reach its saturation voltage?

Why does the voltage output of both amplifier (Vm1 and Vm2 as shown in picture) always reach its saturation voltage?
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182 views

High current SMPS transformer

I would like to have some tips concerning DIY winding of SMPS transformers. Let's consider the following example (for reference only): Input: rectified 230V AC (mean value: 310V DC on the DC-link ...
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2answers
84 views

Optimal PWM Frequency for EMI & EMC

I am planning to design a 65W power supply which will use a PWM frequency of around 100kHz. I am specifically concerned about conducted EMI (not as much about radiated for now). I am currently ...
0
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1answer
253 views

Simulating SMPS with ideal switch in LTSpice?

Yes, this in a portion of a homework assignment (hence the idealized and slightly asinine problem statement). Aside from solving the circuit (which I have done), I am supposed to simulate the ...
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0answers
59 views

Hold switch trigger delayed

I have a small battery driven, microchip controlled project where I use a rotary encoder for toggling/setting various settings. Mostly software based as that is what I'm more familiar with as of yet. ...