A non-isolated DC-DC converter topology which outputs voltage less than or equal to the input voltage

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1answer
44 views

Buck converter charge battery control output voltage

I have a buck converter charging 8 series of Li-Ion batteries ( 8 x 4.2 voltage of charging) with a source of 36 V. I am using this schematic (from here): I know that for a resistive load, the ...
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1answer
52 views

Lift the FB pin of buck regulator [closed]

I have a basic buck regulator with feedback control. \ If I open feedback pin of the regulator (example lift the FB pin), then the regulator will be damaged. Why ? Regards, Azlum
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3answers
72 views

Resistor instead of Inductor in buck regulator [closed]

In buck circuit, If I mount 0E resistor instead of inductor then what will be the problem ? And what is the use of inductor in buck regulator ? whether just for filtering ? Regards, Azlum
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1answer
30 views

Feedback in hybrid power supply

During my research of PSU I came across schematic from Linear's datasheet: 1) Whats the purpose of node which is going from output to SW pin of buck converter? 2) Is node which provides 6V ...
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0answers
40 views

problems faced in buck-boost bi-directional converter with supercapacitor

i'm making a buck-boost converter. it should have an input voltage of 75 v and produce an output of 400v when in boost mode. The 75 v is to be supplied using a supercapacitor. The mosfet used is ...
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0answers
52 views

Regulator design for negative voltage O/P

In my application, I am generating 7.5V from TPS5430 (Buck) regulator and to generate -5V, I am assigning inductor's one leg to input of 7905 for -5V o/p. Circuit is shown. U14 is TPS5430 and U15 is ...
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1answer
69 views

Buck converter Mosfet gate driver

How to turn on a buck transistor via a bootstrap circuit? In my circuit, I use a AVR microcontroller to turn on and off a buck switch. What circuit should I use here? Previously, I used optocoupler ...
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2answers
46 views

Peer Review of Buck Converter

The only limitations I can think of are: Comparator/Schmitt not gate output swing time, and Transistor switching time simulate this circuit – Schematic created using CircuitLab BTW, ...
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2answers
65 views

Help with MOSFET buck converter

I've started learning about Buck Converters, and I made a miniature one on an Arduino prototype shield. But when I turn the thing on, the voltage is stuck at 5v (the voltage input). I tried ...
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2answers
81 views

Available synchronous buck converter chips are bidirectional (current)?

I was going through available synchronous buck converter ICs with external PWM capability (which can be controlled with the help of a micro-controller) and i found this one for e.g. I have read in a ...
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0answers
60 views

Controlled supercapacitor charging with buck converter

I'm building a charging circuit for two supercaps (2.7V, 3000F each) in series. I've got a 12V supply and a buck converter rated to 15A, which I've set to provide 4.8V. I'm using balance resistors to ...
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2answers
87 views

Is there a DC-DC converter topology that can output positive and negative?

E.g. Is there a converter topology that can take a 12v input and convert it to -12 to +12v output with respect to GND? For the record I'd really prefer something that doesn't use rare magnetics. I ...
9
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2answers
859 views

Is it better to boost or buck?

I'm making a solder fume extractor from an old PC fan (4-pin PWM), driven by a mid-range PIC. The fan needs 12V @ max 0.28A for power and a 5V PWM @ max 5mA to control the RPM. So I'll be running the ...
0
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1answer
65 views

Buck converter controlled by a BJT based astable multi-vibrator with zener-based feedback?

simulate this circuit – Schematic created using CircuitLab This is my rough sketch for a buck converter controlled by a BJT based astable multi-vibrator with zener-based feedback. Before ...
0
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1answer
27 views

Why should I bother with Frequency Response calculations in a Spilt-rail buck regulator design?

I'm looking at an existing implementation a split rail step-down power supply (application report). I would like to know what's the big deal with frequency response in the reference design? I think ...
0
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3answers
48 views

The role of reference voltage in buck converters?

I asked a question here which made it quite clear that it's probably not a good start to make something that I plug directly into the mains. Instead, I've decided to build a low-voltage buck ...
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3answers
113 views

Buck converter based switching power supply?

simulate this circuit – Schematic created using CircuitLab I have designed this circuit based on a buck converter. I'm just having trouble finding out which values to plug in. I.E. C1, ...
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1answer
42 views

Summer camp project questions - bike charger

For a summer camp, I am building a bike-generator. Well I have found a few articles about that on the internet, but I have put together a list of questions and I would be really appreciated if someone ...
1
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1answer
86 views

High current Synchronous Buck Converter, MOSFET or IGBT?

I am supposed to design a synchronous buck converter (to be driven by micro controller control signals for switching purpose). The input Voltage range is 10V-15V, and output voltage range is 4V-5V but ...
1
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1answer
47 views

Sanity check my first project: to control my air conditioner with a Nest

I have a window air conditioner. It works well but is a bit old — new enough to be electronic, have a remote and a digital display, but not new enough to turn on from my phone or do anything smart ...
0
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0answers
41 views

How does Mean Well LDD range DC-DC constant current drivers handle dimming?

Mean Well LDD range DC-DC, constant current buck drivers have dimming function. 5v PWM signal allows you to dim the LEDs. Without PWM, you get the full rated current output. Now knowing anything ...
0
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1answer
26 views

Periodic Steady State voltage Buck Converter

What does Periodic Steady state mean with regard to a Buck Converter ? Does it mean the normal operation ? Also, From what I read, the net change in the capacitor voltage in the buck converter is ...
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1answer
48 views

Basic MOSFET question

I am using a P-Channel MOSFET to build a buck converter and change 12VDC, 2A (from a 12V battery) to 5VDC, 2A (for cell phone charging), should I use a MOSFET rated for 20V, 2A or -20V, -2A? I am new ...
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0answers
51 views

Bidirectional Current converter, discrete or IC?

I read in a post (Bi-Directional Buck Boost Converter) that for bidirectional current converters when a higher current is needed, external deiscrete FET transistors have to be used. Like one on the ...
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0answers
150 views

Arduino Controlled Buck Converter

I am building a circuit which consists of a buck converter's duty cycle being controlled by the PWM output of an Arduino. Essentially the Arduino generates the PWM signal from two inputs-the input ...
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2answers
188 views

How to control a buck-boost converter circuit from a microcontroller?

I'm reading about buck-boost DC-DC converters lately and one thing is still not very clear for me. Most of the converter ICs that I've seen have a feedback loop input pin. For example LTC3780 requires ...
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1answer
93 views

Buck-boost converter dropping source voltage

I have two solar panels connected in series, and I'm using them to charge a phone. Together they provide about 7 V when I connect their leads to a multimeter or a basic circuit (i.e. Resistors/etc.). ...
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0answers
15 views

Step load estimation/measurement in a complex circuit

Let's say you have input buck regulator that provides a system rail which is loaded by various other regulators (LDOs, switchers) which power CPU/Memory/RF systems etc, and direct loads (speaker ...
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1answer
66 views

How to reverse the direction of operation of the motor?

For Synchronous buck, half bridge converter, how to reverse the direction of operation of the motor? That would be great if you could explain me with the circuit diagram.
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0answers
23 views

Bidirectional buck stepdown

Does any one know if you get bidirectional buck step down modules. I have found this: ...
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2answers
63 views

DC to DC step-up boost converter compensation pin, what values to use?

Okay, so I decided on a DC to DC boost converter but am having some difficulty figuring out what values to use for the compensation pin capacitors and resistor. The data-sheet really does not go into ...
0
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0answers
59 views

Battery charging via Buck or LDO?

I am supposed to charge a Li-Ion battery (12V 50Ah) and then discharge it over a period of time for testing purpose to measure its efficiency. And this charging and discharging is to be done using ...
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2answers
103 views

P-type MOSFET is not turning off

I am designing a buck converter as class assignment as shown in figure. I have calculated all the value of inductor and capacitor. I am applying PWM to the input of MAX627 MOSFET driver through ...
0
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1answer
64 views

USB powered Switch Mode Li-ion Charger

I want to design a Switch Mode Li-ion charger which uses 5V as input and charges a single cell Li-ion cell. I am referring this AppNote On page 4 they have given the equation to find inductor value ...
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2answers
298 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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0answers
30 views

formula of finding maximum output capacitor for buck converter

If we are asked to calculate maximum output capacitor, does the formula of finding capacitor applies the same to both maximum and minimum? Or is the equation totally different?
0
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1answer
109 views

Buck converter not working

I designed a buck converter on breadboard as shown in the picture. I am applying PWM from my microcontroller. I am not sure why this circuit is not working, I have spent so much time on it. Is there ...
0
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1answer
80 views

How do I calculate the duty cycle range for DC-DC buck converter?

Question: A buck converter supplies power to a microprocessor with a core voltage of 1.2 V and peak power requirement of 2A. The supply for this buck converter is a lithium battery with a nominal ...
0
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1answer
86 views

Usb input current requirements for a power bank

My project is to take solar power from a 6w/6v panel, run it through a buck circuit tuned to 5v and charge one of the LiPo power banks. I perceive a buck circuit would do better at efficiency than a ...
2
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1answer
48 views

Buck Converter Multiple inductors

I'm looking at a height constrained application, that's making it difficult to find the power inductors I need. What's wrong with say using 4 inductors in parallel to get more current? I know the ...
0
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1answer
83 views

Rise time and fall time calculation of an integrated switch?

Following the analysis regarding the selection of buck converter for my application (Buck converter efficiency Vs load current:). Now I am trying to estimate the power dissipated in the integrated ...
0
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1answer
54 views

Rechargeable battery configuration for 5V

I have 6x 18650 (3.7v) cells. I'm trying to build basic power-bank and wondering what battery configuration would be better for minimizing power loss in voltage regulation/conversion process? Edit: ...
0
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2answers
82 views

Buck/Boost Converters— What's the 'cost'?

I am trying to source (hopefully) a single power supply for my present project. From this single source I was thinking of using appropriate buck and boost converter circuits to fan out the various ...
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1answer
128 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 -. ...
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1answer
77 views

Buck converter efficiency Vs load current:

Can somebody explain how does the efficiency of a buck converter increases with the increasing load current?
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1answer
53 views

Synchronus Buck Converter

So i am designing a Synchronus Buck converter 12V - 5V with 12 W of power at the output. This means that my output current will be on average 2.4 A. Now for the feedback I am using an Arduino. I will ...
0
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1answer
41 views

Buck converter operating frequency range:

I am looking for a buck converter IC for my project. In the data-sheet if the operating(or supporting) frequency range has not been mentioned, then how do we know about the range of frequencies it ...
1
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1answer
113 views

Can I measure inductor current by adding a secondary winding?

I have a buck converter and I want to add a current loop to it. I don't want to use a hall-effect sensor or something expensive like that. I think it is not practical to use a sensing resistor since ...
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2answers
69 views

Buck regulator output

The output of buck regulator is the average value of the output across the regulator. So below are my questions. 1) How the average value is coming across the load resistor practically ? 2) ...
0
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1answer
114 views

Current output of a solar panel when connected to battery and load

I am trying to build a microgrid (final year project) where a 100-250 W 48V solar array will charge a 24V battery bank and a couple of 24V loads (40W lights, 60W fan). Batteries used (7 of this in ...