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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48 views

How can I change the power supply from one to another?

I am not an electrician, electronic or anything that will relate me with your interesting profession, but I am a Project Engineer, Mechanical Engineer, etc. and I am working in my spare time in one of ...
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33 views

If I have a 12v battery which is connected to an inverter [on hold]

I am a Project Engineer which like to explore as a hobby other areas and I have a question for your expertise to advice me to follow the right way, here is my idea & questions: I want to use a ...
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2answers
49 views

What is the maximum power an inductor can transfer in a SMPS?

I'm trying to analyze a boost converter circuit. I have all the specs for the inductor used, including inductance (6.8uH) and saturation current (1A). This runs from a 3V supply. I'm wondering if ...
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38 views

Momentary tactile switch ON when unit connected to AC power - circuit modification

I have an air conditioner unit that after plugging in the power cord to the power outlet is off. You need to press a momentary switch on the circuit board to power the unit on. Now I would like to ...
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1answer
76 views

Three questions about the use of a transformer in switching power-supply

In this document (an introduction to switching power supplies) a boost-mode switching power supply is presented: it has a simple inductor, diode, capacitor and load. Then (page 9) it is specified that ...
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1answer
54 views

DC-DC SPMS Boost Converter DCM Prevention

Sorry for the long question, it's really opinions I seek which is why I felt I needed to explain the scenario and how much I know/don't know. I would really like some input on my design. I am ...
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14 views

Application Note 101 Switching Regulator spike simulation

Has anyone every tried creating the SMPS ripple and spike simulator (as described by Jim Williams), using Spice. I am trying to do so for a week now, but still not getting anywhere close to the curves ...
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46 views

LM2596 voltage dropping

I bought a cheap LM2596 adjustable buck module from eBay and I connected it to 19V power supply and adjusted it to 5V output. The problem is that when I add load the voltage drops, which is not what ...
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1answer
66 views

Power Switching with Microcontroller

I am in the process of designing a device for a uni project. As a requirement, we are required to have a very low power consumption whilst in standby mode. Our plan for this, was to have our 2 x +-5V ...
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38 views

LT8609 DC/DC stepdown not working correctly

I am using this exact circuit with the exception of a 2.7uH coil (closest available at the local parts store). It is an example provided in the LT8609 datasheet: The only load is an LED with a ...
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1answer
60 views

how to design a rheostat which gives me fix 24V supply for different input of 24V,48V,110V,220V [closed]

i want a constant voltage output using rheostat. It can be any electronic circuit control or by appropriate tapping.
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4answers
132 views

Switch Mode Alternative to LM7805/LM7905

I am attempting to design a dual rail power supply PCB for a university project. There are a number of restrictions - namely that it maintains > 80% efficiency regardless of the current draw. I was ...
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2answers
108 views

How to achieve the max efficiency from a Buck converter

I have a question about switching step-down regulators. (As I stated in my previous questions, please consider the fact that that I'm not very expert, so feel free to reply/talk as if I were a ...
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2answers
41 views

TEC 12706 not drawing more than 1.6A when powered by a 12V PC SMPS

I have recently bought TEC 12706 device from Sunrom.com; The specification says that the device can draw more than 6A current at 15.4V and internal resistance is ~2 ohms. But when I measured the ...
2
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1answer
81 views

Analog & Power Ground Planes Doubts

Working on a new board, I have to face some requirements to ensure the performance of the whole system once is manufactured. PCB is a 4-layer one, and it has both analog and digital components. But ...
2
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1answer
307 views

Can massive ammounts of 0603 SMD 1uF ceramics displace power caps?

Edit:Warning: there's an error in one of my assumptions in this question, which more or less invalidates it. See Tom Carpenters answer. I'1m designing a switched mode power supply, and of course need ...
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1answer
73 views

How to shutdown the entire system after certain time period?

Background I have TPS61240 Boost converter module. In my system, TPS61240 is used to convert 3V DC to 5V DC. This 5V supply is then used to power whole system. Moreover micro controller driven system ...
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2answers
57 views

Eliminate mains common mode ripple from external power supply with poor isolation

I've got a number of battery powered devices which require periodic recharging. I'm using notebook chargers to provide for the input voltage and they work fine... most of the time. Occasionally they ...
3
votes
3answers
179 views

Should I be concerned about using off-the-shelf inductors in high-voltage switching applications?

I'm interested in building a SEPIC converter with an input range of up to 1200 VDC. Digikey lists a large number of inductors, which may be viable for my application. But I'm concerned about the ...
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1answer
63 views

Trying to determine if transformer is safe

I am building a switching power supply with an isolating step-down transformer. Part numbers: Controller: LT3798 (http://cds.linear.com/docs/en/datasheet/3798fa.pdf) Transformer: 750312872 ...
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2answers
1k views

Are typical computer power supply units leading or lagging power?

Computer power supplies often have "power factor correction" features which raise the power factor in use to levels close to resistive loads (1). I'm curious what, in the absence of power factor ...
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2answers
135 views

Noise resistant microcontroller used in high power inverters for PWM generating [closed]

In order to generate PWM pulses for driving switches of a high power(80 kW) three-phase inverter,which microcontroller family(and which member) is suitable? ,taking into account the noise effects on ...
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1answer
50 views

Increasing 12V Rail current on power supply for mobile computing

I am building a miro-itx slimline pc for my mobile home that is powered by solar. I have selected a GPU with a rated TDP of 120 Watts and a CPU with a TDP of 53 Watts.I purchased a DC-DC buck ...
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44 views

Can I use a 100-240V AC 5A Time Delay Relay to spread out startup of drives?

My storage enclosure has dual power supplies for failover. Specs for each PSU:100-240VAC 5AMax continuous output power: 250WTotal power on +3.4V & 5.V is 128W mx I need to delay initialization on ...
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43 views

Switching regulator discontinuous mode

I designed a step down converter for my circuit using the following converter: http://www.ti.com/lit/ds/symlink/lm1575.pdf It converts 16V to 3.3V. As I summed up the current consumption of my ...
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1answer
50 views

What is the circuit for the PMOS driver found in synchronous buck regulator ICs?

Some synchronous buck regulator ICs sport a NMOS lowside switch and a PMOS high side switch. I understand why these use a PMOS/NMOS pair instead of a NMOS/NMOS pair, but I can't seem to make sense of ...
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1answer
57 views

Power inductor maximum DC current rating

I am selecting a power inductor for my power supply. The only significant source of current draw is a servo motor that draws about 200mA - 1A for 500 ms for less than 10 times a day. Consider the ...
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2answers
82 views

Switching regulator (TI LM2678) not working on load > 100mA

I am a (joung) programmeer and I recently began studying some electronics&AVR programming. I am trying to use a step down voltage regulator (LM2678-5.0) to transform battery voltage (9/12V) into ...
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1answer
40 views

switch mode power supply frequency change

I am relatively new in the field of Switch Mode Power Supplies but I was looking at the Flyback converter with an input voltage of between 30V to 88V DC and an output that would charge a 24V lead acid ...
3
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1answer
66 views

Switching Supply Noise Filter for Audio Circuit

I want to make an external power supply for various pieces of "vintage" audio gear that run on +-18V, +48V, -9V and so on. So the plan is to put several off-the-shelf AC/DC switchers (like Meanwell ...
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38 views

AVR decoupling capacitors in 64kHz switching power supply

I am working on a compact variable switching power supply (sepic topology) that is controlled by an Atmega328p microcontroller. The unit is powered by li batteries at 3.7 volts. Everything works ...
2
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1answer
44 views

Continuous gate drive for high side mosfet using ir2110

I plan to provide continuous gate drive for high side mosfet using ir2110. According to ir2110 application note, a 555 timer is used as charge pump for continuous gate drive but the schematic is hard ...
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1answer
20 views

Using a SMPS converter IC as a controller

I'm building an LED driver using the LM3410. The internal switch supports a current of about 2A which should be adequate for my needs, but if I need more, can I use an external MOSFET to act as a ...
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2answers
88 views

5V 5A rail controlled by 3.3v microcontroller - dual switching or power mosfet?

I think this is a common situation so hopefully an answer helps more than just me. I have a 3.3v low power MCU which will be controlling a 5v 5A run of LEDs. When the LEDs are off the system will go ...
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1answer
58 views

are sensing power supplies and switching power supplies the same thing? [closed]

What is the difference between sensing power supplies and switching power supplies? Are they the same thing?
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61 views

Current sense in SMPS, how does it work

I've read a couple of application notes where it is stated that measuring current to use that value in the feedback loop helps stability because sensing before the RC net takes a pole away (see ...
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1answer
107 views

Discrete LED Driver Topology

I have drawn the above schematic by reverse engineering a locally available LED Bulb. I was expecting to find an IC in the driver board but instead found this discrete circuit. Googling "Discrete ...
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1answer
69 views

Boost converter with 2A load

I'm trying to put together a boost converter to take a 11-14.4v input and boost it to ~17v with a max current of 2A. Most of my designs (made either by calculations done by me or a calculator tool ...
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0answers
46 views

Buck Converter power supply based on astable oscillator and zener diode feedback?

simulate this circuit – Schematic created using CircuitLab I've asked several theoretical questions about this before, but I've assigned values and changed my circuit quite a bit. The ...
1
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1answer
69 views

Step-down converter and ceramic minimum ESR capacitor

I'm building a step-down converter, based on the TI TPS5450, which provides a reference design and various considerations on the capacitor. Even on the minimum ESR required. But when states "The ...
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1answer
63 views

SMPS control components and technologies

Preface: the switch-mode power supply is a flyback power-factor corrected AC-DC converter. I'm currently using a combination of AVR microcontroller (ATmega64A) with some analog (such as DACs) and ...
0
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1answer
34 views

Do I need to place any additional component(s) getween isolated grounds?

Initially I bothered with this question regarding isolated flyback switch mode power supplies. However I'd be happy to investigate this question dipper. So as the output of the power supply is ...
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2answers
102 views

TPS61240 Boost converter IC is not working at all?

I am currently using TPS61240 as a boost converter for my project. As i did not have any sample previously so there was no way I could test it. I ordered the IC and placed it on my final PCB directly. ...
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1answer
62 views

What for is L1 coil?

I can't understand why L1 has four windings? And how we get -12 V if there are two diodes connected towards each other. How will current of -12 V flow? And do thos fours windings work as ...
2
votes
3answers
126 views

Feasibility of very high temperature ac-dc switching power supply

I'm involved in a product design (on the mechanical side, to be clear that I'm not an EE) where we need a very compact ac-dc switching power supply that will take 90-300vac, 50-60hz and output 5 watts ...
0
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3answers
132 views

Converting 12-220V to 12V?

Are there any Analog/Maxim (I couldn't find a switching regulator with these characteristics on their websites) ICs that can step-down a voltage between 12 and 220 V (coming from a generator) to a ...
2
votes
1answer
144 views

wiring AC switch with DC led

This is a follow up to a previous question I had answered. I'd like to show the following diagram. Here, I have laid out (crudely) a diagram that has 120v-110vAC from the wall going to a push ...
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1answer
84 views

What does Boost Converter With 2-A Switch mean?

I am new to boost converter technology. All i want to know is what does switch current indicate.
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1answer
69 views

Programming undervoltage lockout in Boost(Step up) converter

Requirement is to convert 3 V (1.5 x 2 alkaline batteries) dc voltage to 5 V Dc voltage. I know battery voltage decrease with the use and i am required to set a threshold voltage so that if battery ...
0
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3answers
208 views

Variable voltage supply (0V , 5V, 7V, 10V, 16V) rotary switch

I need to build a variable voltage supply that can generate 0V,5V,7V,10V,16V. My idea is to use a rotary switch and zener diodes. So far I got all the outputs correct with little difference from my ...