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

learn more… | top users | synonyms

0
votes
2answers
74 views

Charging supercapacitors with Buck converter. Do I need to cut power once charge is reached?

I am trying to build a supercapacitor charger, and as I don't particularly have a good handle on the risks of such a thing, I'm hopping on here to give some information. I am using a buck converter ...
-3
votes
1answer
70 views

How to the calculate the value of capacitor placed in series with transformer to avoid flux walking in a buck converter? [closed]

The dc value of current in primary increases(in -ve direction) as time passes, so I need a capacitor in series with transformer, but don't know what value capacitor should I use. filter capacitor = ...
3
votes
1answer
63 views

Transistor Level Shifting in Buck-Boost Converter

Ive been reading some of the LT application notes on Jim William's Analog Circuit Design book, and there's something I don't quite understand. I'm attaching a scan of the circuit in question. The ...
0
votes
1answer
38 views

Is it safe to use a non-isolated buck converter for an LED driver?

I am making a commercial LED lamp. I am using a non-isolated circuit. I am using buck converter. Is it safe? Can I use a buck converter after the bridge rectifier?
1
vote
4answers
101 views

Does a “Buck Step Down Voltage Regulator” provide constant output voltage regardless of input voltage?

I've got a small solar cell panel rated at 20V on a good sunny day. I need to regulate this down to 13.8V to charge a lead battery. Can I use a "Buck Step Down Voltage Regulator" for this? I'm ...
0
votes
2answers
77 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 ...
-1
votes
3answers
114 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
votes
1answer
202 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. ...
0
votes
3answers
100 views

How are these RC values calculated in this buck converter?

Buck converter: LTC3824 The datasheet says: VC (Pin 4): The Output of the voltage error amplifier gm and the control signal of the current mode PWM control loop. Switching starts at 0.7V, and ...
0
votes
0answers
64 views

powering a micro in sleep mode

I've got a setup that will spend 1/3 of its time running a few servos (figure up to 1A @ 5V), 1/3 running sensors / other (<300mA @ 3.3V), and 1/3 of its time sleeping with just the watchdog ...
0
votes
1answer
61 views

Power Supply Design: Am I after DC-DC Controllers or DC-DC Converters?

I'm trying to design a variable dual rail power supply, which has an unregulated input voltage of ~11V and a maximum output current of 1A. I want to have a 5V/12V/20V positive and negative output. ...
1
vote
4answers
162 views

How to drop 240V DC to 5V DC

I would like to drop a 240V DC voltage to a 5V DC voltage to supply electronic. The 5V stage needs less than 5mA in current. The solutions I looked at are: Resistor divider (Not really ...
0
votes
2answers
49 views

How to theoretically determine ESR of a capacitor and DCR of an inductor for a buck converter?

How can we determine ESR of the capacitor and DCR of inductor theoretically in the design of buck converter, without using an LCR meter?
0
votes
2answers
106 views

using multiple buck step-down voltage regulator modules to convert 50-400V DC to 12V DC

I would like to generate ca. 12.5V, 8-10A, DC power from an incoming voltage between 50 and 400 DC that has been rectified from 3-phase AC coming from a brushless motor acting as a dynamo. I will ...
0
votes
0answers
40 views

Buck converter effect on amp draw

It was my understanding that the circuit will only draw the current thats needed - a 1A servo will only draw 1A. I have a rather large project so I am using a 24V 5A rated wall adapter, and using ...
1
vote
1answer
73 views

What is the best way to power both my 5v 16 x 16 Neopixel matrix and the 9v Arduino that drives it? [closed]

I have 4 Adafruit 8x8 Neopixel matrices interconnected to form a 16 x 16 matrix driven by an Arduino Mega. Right now I am using two different power sources to power the matrix and the microcontroller. ...
6
votes
5answers
882 views

Extract 5W low voltage power from 3000W high voltage source

I have a solarpanel array that generates 600V, 5A (3kW). I want to create a small electronic unit to measure the DC current and voltage and transmit this wireless. For this I have an electronic board ...
0
votes
0answers
32 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 ...
0
votes
2answers
47 views

Getting closer to figuring out my battery requirements

I have been doing research for at least a week and am still a bit confused, but think I am getting to the point where I am close. I need to power 5V 3-5A. Some days this power source will hook up to ...
2
votes
4answers
370 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 ...
1
vote
0answers
89 views

Designing an efficient PSU

I am designing a PSU capable of producing 5 watts @ 5V 1A. The design will power about 12 RGB LEDs (totaling about 400mA @ 5V) and a audio class D 1.4 W amp. Space is no issue but efficiency and cost ...
1
vote
1answer
66 views

AP3431 burning up with no load on it

EDIT 1: I was able to get it to work, but I am not at all sure what happened here... I decided to build this circuit again - exactly the same layout and parts (see original question below). As soon ...
1
vote
1answer
83 views

Strange oscillation in buck converter (AP3431)

I am having a lot of trouble getting AP3431 to work reliably. The converter works properly for about 30 seconds, and then oscillations begin, with brief periods of normal function. Here is how it is ...
1
vote
0answers
104 views

Suitable switching/buck regulator - Vin = 24V and Vout = 5V and max current = 0.4A

Due to a sudden change in design requirements with regards my circuit supply voltage I'm looking to change my voltage regulation on my circuit from the classic LM7805 linear voltage regulator to a ...
1
vote
3answers
201 views

Effect of using buck converters in parallel

What is the effect, downside or purpose, if any, of using buck converters in parallel? For example, to connect the Vout and Gnd together on two converters. Could this be used to increase the current ...
0
votes
0answers
37 views

How to configure LTM4641 buck converter demo board

When I put a load greater than some small Ampere, about 5mA I think, the board shuts down. Vout goes from 4.97V to zero in about three seconds. I want this to deliver 10A load at 5V. The Manual for ...
1
vote
1answer
121 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 ...
1
vote
2answers
154 views

Buck using discretes - Driving p-MOSFET using n-MOSFET

we are designing a buck using descretes. I have problem OFF time of Control MOSFET(U1) driver(T1). in OFF time, Gate of U1 is raising very slowwly to 12V which makes U1 always ON. Which in turn makes ...
8
votes
4answers
579 views

Boost or buck regulator for battery life?

I want to make a wireless sensor node that will run at about 2.5v. I am trying to decide between running 3 alkaline batteries in series with a buck converter or in parallel with a boost converter. I ...
2
votes
2answers
72 views

Powering DSLR with buck/boost convertor

I've been experimenting a bit with time-lapse photography lately. Still basic stuff. Right now I have to change batteries every so often which is a pain because it's hard not to move the camera when ...
0
votes
2answers
103 views

How can I regulate a 5V battery?

I am trying to use this 5V RAVPower battery pack to drive some electronics and a high-current load: ...
0
votes
0answers
229 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 ...
0
votes
1answer
91 views

Is it possible to use buck boost converter at the same time?

I have a input source from 50mV to 4V and I want a fixed/regulated voltage of 3V. Input voltage is varying every time so in order to achieve the 3V I have to implement Buck as well as Boost converter ...
1
vote
2answers
275 views

Charging 2 Li-Ion Batteries via a single charger

I'm currently building a portable USB charger. It uses 2 Li-ion batteries in series connected to a USB port via a 5V regulated buck converter. While a single Li-ion battery would suffice for most ...
1
vote
2answers
250 views

How to adjust output current on a buck converter?

I 'm planing to use a zinc–carbon 9 V battery to power up: the circuit that battery belongs to BeagleBoard-xM I 'm thinking of using a breadboard, in order to power up both circuits. ...
-5
votes
1answer
102 views

what are the consequences of not using a diode in a buck converter, and why a diode must be used?

what are the consequences of not using a diode in a buck converter, and why a diode must be used? which component is most likely to break down in a buck converter circuit if a diode is not used?
2
votes
1answer
132 views

Extracting the Most Energy From a Capacitor

I have a 5V super capacitor which I'm trying to extract the most energy from in the most efficient way possible. This capacitor is tied to the input of some regulator (which is the question of this ...
1
vote
0answers
64 views

Multiple stacked DC-DC converters

I am trying to minimze the output voltage ripple of a 4-layer pcb power supply and am curious as to what approach would be better. So I have 6 low voltage high amp buck converters feeding 6 chips. ...
2
votes
2answers
108 views

Reducing voltage for solid state relay

I have a solid state relay which wants a 1.25-2.5V "activation" input, but my output from the micro controller is 5V. Is it possible to use a zener diode for this? Or do I need a buck converter? I ...
1
vote
2answers
130 views

What PWM frequency to use on SMPS

Just to give a little back ground on the project - I am currently building a buck converter linked up to 2 * 250W solar panels in parallel, then use an MPPT algorithum to track the max power. I will ...
0
votes
1answer
85 views

Can I use constant current LED driver as input to Buck regulator?

I have an 100W constant current LED driver that I bought in error but maybe I can use it in another way. I want to use 3 buck regulators to pwm control each individual color of 90W RGB LED. Can I ...
1
vote
3answers
440 views

DC-DC Step-Down (buck) converter 5V 10A 50watt, not understand how to size the supply

I have a 5V 10A 50WATT DC step-down converter: http://www.powerstream.com/dc-24V-5V.htm I'm just not understanding how to size the power supply needed to drive this converter at max power. I have an ...
2
votes
2answers
171 views

synchronous buck ls-FET switching losses and dead time minimization

I'm designing a Synchronous buck converter. I'm having doubts regarding the following: In the rectifying period of the converter, using a Schottky diode in parallel with the low side MOSFET will ...
3
votes
1answer
120 views

buck-boost, SEPIC IC out 3.3V and min 500mA 0.1" packaging

I am building some sort of navigation device for a logisitics project in my company. The whole thing is going to be battery (6V) powered, so I'm looking for every possible way to avoid losses to heat ...
0
votes
3answers
95 views

How to gauge resistance on parallel circuit with step down buck regulator

I'm trying to create a circuit with two loads in parallel ( essentially piggy backing one circuit on the power supply of the other ). Circuit 1, the main circuit requires ~900ma at 12v. Circuit 2, ...
1
vote
3answers
149 views

Correctly wire up a Switching Regulator

I am looking to use a Texas Instruments MC33063 Buck/Boost regulator. I have never used a switching regulator before so this may be a conceptual issue. My input voltage will probably be anywhere from ...
1
vote
0answers
61 views

TI's bypass mode step-down converters

Texas Instruments encourages the use of the TPS62730 step-down converter with bypass mode along its RF devices. Does this mean : its noise is low enough not to affect RF ? Thus being a more ...
2
votes
1answer
286 views

Audible noise in DC-DC buck converter

In my design, I have a +3.3V SMPS that provides power to digital circuits (microcontroller, EEPROM, etc.). The microcontroller allows applying a 100Hz PWM signal with variable duty cycle and with an ...
4
votes
2answers
217 views

Can I use digital pots for my feedback resistors to a buck-boost regulator?

I'm working on a design, and this will be my first attempt at a buck-boost regulator. I need the output to be variable because my application calls for different voltages under certain conditions. ...
1
vote
1answer
176 views

Buck boost converter

I have noticed that some buck boost converters say "led driver", some have step down/up control and what looks like a display voltameter and ammeter, they are adjustable to 5 Amps/32v. Obviously these ...