DC-DC conversion. Implies conversion of a DC voltage level up or down. Electronically it can be done by many kinds of circuits, depending upon the application (charge pumps, voltage multipliers, linear voltage regulators, boost/buck switched converters, etc)
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2answers
56 views
How should sampling frequency, switching frequency, control loop update frequency, and anti-aliasing filter corner frequency relate?
Suppose one is designing a processor-controlled switching supply. In general, how does one properly select switching frequency vs. control loop update frequency vs. feedback sampling frequency vs. ...
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2answers
93 views
Is something wrong with my frequency selections for a buck converter controller? [on hold]
I'm designing a processor-controlled buck converter. I'm seeing some instabilities, which I suspect may be due to improper frequency selection at different points in my system. I'm trying to regulate ...
3
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2answers
114 views
Understanding Boost Converter
Theres a very good explanation for the Boost Converter on Wikipedia. But it is a very mathematical explanation. How would you explain the Boost converter to a non Math person like me?
2
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2answers
82 views
Buck converter with op-amp, inductor issues when load changes
I'm looking at the designs for a simple buck converter which has the P mosfet, inductor, capacitor and reverse based diode. Instead of PWM, I'm trying out to use an op-amp to switch the P mosfet but ...
5
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1answer
93 views
What is the purpose of those capacitors on this DC DC switching mode step down circuit?
I am designing a PCB board with a 12V to 3.3V DCDC switch mode regulator. I am checking some circuits and datasheets, and I found some capacitors that I would like to understand.
I will use the ...
2
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1answer
65 views
Boost Converter unstable with rapid current changes
This is a follow-up to the question I raised previously on a previous design (Unstable boost converter with short bursts of current draw) where my boost converter was producing large output ripples ...
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1answer
64 views
Extending a switch mode power supply controller IC to work under higher input voltages
I have a AP6502 IC, which is a cheap DC-DC buck converter. It converts a DC voltage in the level of 4.7V-18V to a DC voltage of 0.925V-16V. I works under 2A current maximum.
Example Usage of AP6502 ...
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1answer
41 views
DC-DC Converter Unloaded Voltage
I have a DCP010512BP 5->12V DC-DC Converter from Texas Instruments. With a supply voltage of 5.00V on Vin and a 4.7uF ceramic cap across the output, I read the output voltage as 21.0V with a digital ...
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2answers
120 views
Unstable boost converter with short bursts of current draw
I'm designing a boost converter that boosts a 9V battery to about 10.5V. The objective is to maintain 10.5V despite the V_in reduction due to battery dissipation, e.g. boost 6V to 10.5V. This boost ...
8
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2answers
144 views
If I put multiple isolated DC/DC converters in series, can I add their isolation voltages?
Suppose I have a DC/DC converter that's rated for 2250VDC isolation for one minute. If I put two of these devices in series, making sure to maintain proper clearances on my PCB, do I get an effective ...
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0answers
87 views
Trying to choose a high current DC/DC step-down converter
I'm working on a project that will drive a long length of LED strips, the WS2811 kind built into 5050 LEDs on a flexible strip. I've got most of the project worked out, except for power. Since it ...
4
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2answers
92 views
Step-Down DC-DC converter question
I want to use Power over Ethernet (48V, 30W best case) to power something that's going to require up to 15W at 10V. That means I need to step down the PoE voltage but step UP the max current. As I ...
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1answer
56 views
Charging 72V battery bank from 15VDC source
Using a constant source I have a DC generator that can produce over 15 volts continually. I have a 72 volt battery bank and another 72v-motor that runs off of that battery bank. How can I best connect ...
1
vote
1answer
133 views
How to construct a low input voltage DC-DC converter if no suitable IC is available?
I need to convert a very low input voltage (around 0.5V) to a steady 3.3V output to deliver 50-80mA current with relatively high efficiency (>= 80%). After some research, it appears that some DC-DC ...
2
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1answer
153 views
1.5V to 5V dc-dc converter
I'm looking for a dc-dc converter using only basic components (coil, condensator capacitor, transistor, resistor, diode, zener diode).
Because when ordering a specialized component from the internet ...
6
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2answers
158 views
Is constant current achievable with a dc/dc converter?
I'm an electronics novice and part of a rocketry club. During the 4th of July we try to do a mass launch of rockets. Doesn't always work. I thought about building a capacitive discharge circuit to ...
7
votes
2answers
155 views
Feeding a Full-Bridge from a Boost Converter?
I have been researching about designing a 3kW DC-DC Converter (Vin 12V from a battery, Vout 350VDC) and actually wired up a simple isolated Full-Bridge based DC-DC converter a few days back converting ...
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2answers
84 views
Choosing a Switchmode Converter for a Battery Powered Project
I'm currently designing a battery powered, 2xAA in this case, project. The problem that I have is very simple, I want to power a DS1307 (the only part in my circuit which requires 5V). I've looked ...
5
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1answer
97 views
What is a switching node island?
I was reading the LM2734Z datasheet and in the PCB Layout Considerations section, it says "There should be a continuous ground plane on the bottom layer of a two-layer board except under the switching ...
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2answers
111 views
Advice on safe discharge circuit for HV Capacitors (400v)
In designing a relatively high voltage DC-DC converter, my output capacitor happens to be a 100uF electrolytic charged to 400v nominal. Efficiency is a design constraint, so I would like to know of ...
4
votes
1answer
101 views
12V -> 3.3V DC step down at low current
For a project that I've been working on, I want to drive a couple of ICs and several LEDs from an ~12V supply (lead-acid battery). I think the whole thing should draw about 100mA, so I didn't really ...
2
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3answers
321 views
DIY protection for 12V electronics wired directly to a marine 12V battery system
On my boat I have a number of electronics devices that run on 12V DC and normally get their power from an AC transformer. They include a media player, a network router, and a portable hard drive. ...
2
votes
4answers
164 views
What actually is the output current of a boost conveter?
What I understood at least at a basic level the operation boost converter, the inductor supplies output current when the switch is OFF.
When the switch is ON the the load current is taken current ...
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votes
2answers
55 views
Current mode PWM Controller
I'm analyzing a power supply design. A Current mode PWM controller is used to step down the i/p 45-57 V/350 mA to 5 V/3 A. The design uses this part, ...
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3answers
167 views
How can output voltage and current of a DC-DC converter both be higher than input?
I'm working on a TFT LCD Supply and using a step up DC- DC converter from Maxim, the MAX17062. I want to find the input current. The datasheet lists that as 2.5mA. I have a doubt: if the input current ...
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2answers
125 views
5v solar batterypack to 12v output
This is just a concept I was thinking about.
I have an arduino project with some dc motors that needs to run outdoors for a long time. The DC motors themselves do not need to run all the time, ...
2
votes
2answers
222 views
DC/DC Converter minimum load?
I'm using the NTE0506MC DC/DC converter which boosts 5V to 6V. The output voltage I'm measuring with no load is 9V not 6V. In page 3 of the datasheet they mention that it needs a minimum load of 10% ...
7
votes
1answer
143 views
Its a good practice use dc-dc converters and linear regulators in the same design?
Its a good practice use dc-dc converters and linear regulators? Or its better don't mix them?
Better use all linear tecnology or dc-dc converters in "cascade" or dc-dc with multiple outputs?
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1answer
172 views
Home made USB charger based around LM2596: Smoothing caps
I'm embarking on building a home made mains USB charger based around an LM2596 DC:DC converter. I had a couple of Newbie questions.
Can I connect 5 or 6 USB plugs to the output of the LM2596 ...
2
votes
2answers
147 views
DC/DC Booster to 5v 500ma?
I'm trying to find a circuit capable of boosting a normal alkaline battery or maybe a li-po to 5V/500mA. I want a through hole IC to try it on the breadboard.
Vin could be 2.5V (or lower) and maximum ...
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2answers
95 views
Dirt cheap 3-12v DC/DC isolatior chip?
I'm creating a box that will have an external TTL trigger. I want to isolate my box's power/ground from that of the triggering device.
Obviously, an optoisolator is the way to go (eg. PS2502).
...
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3answers
225 views
DC to DC converter [closed]
my question is, I need to drop the voltage down from a car battery, probably 14v or 12v, down to 5v to power a picaxe microntroller. Would a voltage regulator work fine for this? which one would work ...
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1answer
105 views
On/Off control of step-up DC to DC converter
I simply want to on/off control Vout of "step-up DC to DC converter(NCP1402)" ; toggling chip's CE pin by AVR GPIO, but Vout does not go 0V when CE pin set to Low(<0.3V = disabled).
The datasheet ...
0
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1answer
120 views
Switching Regulator (LED Driver) “Flickers”
I have a constant current LED Driver (LM3410) that effectively functions as a switching voltage regulator to provide enough voltage for LEDs in series. When I power it with a relatively low voltage it ...
4
votes
1answer
526 views
In a boost converter, should ground plane be placed underneath the gate trace?
When designing the PCB layout for a DC-DC boost converter, one does not place a ground plane under the inductor, to prevent induced ground currents. Also, for SMD MOSFETs, the drain (switch node) ...
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2answers
231 views
LDO or switching Regulator
My requirement is 3.3V 1A output from 5V (this 5V is derived from DC-DC regulator 24v to 5V 1.5A)
i have chosen NCP5662DS33 LDO , but which is best one to use for this current requiremnt ?
i have ...
2
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2answers
119 views
Building a motorcycle accessory power connector - Values for capacitors and diodes?
After finding out that a component I wanted to base a circuit around isn't suitable, I've found a possible replacement part, but I have questions about the values for Cin and Cout capacitors and the ...
0
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1answer
152 views
5V USB for motorcycle using MC33063A
I'm trying to build an accessory power device for my motorcycle. At the moment I'm using the board from a ripped apart USB car charger for the 5 V part, but I'm trying to build a complete circuit.
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10
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3answers
454 views
Full-bridge converter rectifier kicks
I'm in the process of building an 8kW isolated DC/DC converter, full-bridge topology.
I'm seeing some interesting phenomena on the diodes. When each diode becomes reverse-biased, a voltage spike ...
0
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0answers
117 views
Atmel UC3L/SAM4L + 2.8V peripherals li-pol charger and power rails (PMU/PMIC ?)
I am designing a very tiny low-power Atmel UC3L (or SAM4L) project and I need the smallest solution for safe Li-Pol charging and to provide 2.8V and 1.8V power rails.
I found some LTC parts with dual ...
0
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1answer
216 views
Atx psu 7v output
What is an easy way to get 7-7.2vdc from an scavenged atx psu? I had thought about using a lm317 but I'm going to need at least 5-7 amps of current, and the 12v-5v split just sounds like a really bad ...
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vote
2answers
624 views
Designing 14.8v Li-ion battery charger + 5v power regulator for Raspberry Pi (of other 5v device)
The RasPi requires a steady 5V and to this end I build a power regulator circuit using a LM2576T, similar to the one on page nine of the latest MagPi magazine.
This works great with an external ...
1
vote
1answer
396 views
how can I made a 12vdc to 19vdc booster/regulator?
This is a fairly specific question, but I think the answer could probably be applied to various voltages.
I would like to make a circuit that will take in a 12-14volt source (from a lead acid) that ...
4
votes
2answers
430 views
DC-DC converter with 200V output?
First of all, I'm a mechanical (robotics) engineer, so I do not know much about electric power systems.
I'm making a mobile robot that should have electrical motors and drive system.
The problem is ...
2
votes
2answers
764 views
Interface a 5v pressure sensor with a 3.3v ADC
I'm trying to interface a pressure sensor (MPXV6115vc6u) with a 3.3v ADC. My board is providing a 3.3v (it's a XBee power regulated board, via a Li-Po battery).
To wire the MPX sensor, I need to:
...
0
votes
1answer
125 views
DC-DC Up-Conversion without Switching Electronics
I have a project where I am trying to find a means of powering a sensor with the following requirements: 24-30 V and a regulated constant current of 2 mA (about 60 mW). The latter requirement I will ...
2
votes
3answers
682 views
Step up DC/DC 5V -> 6V
I have a circuit that runs 5V. I need to integrate a CO2 sensor that requires 6V. What would be the simplest, most cost effective way to do this? I need about 200ma for the sensor
7
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3answers
4k views
Regulated 3.3V from a Lithium-ion (or LiPo) battery
Background
I wish to power my circuit with a Lithium-ion or LiPo battery (likely a battery with around 1000 mAh capacity). These batteries have a voltage that goes from 4.2V to 2.7V typically during ...
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vote
3answers
346 views
Calculate output voltage and current of a boost converter
If I have two AA rechargeable battery (1.2 V, 2000 mAh) connected in series, and I then connect it to a boost converter (DC to DC converter) so that the output voltage is 5V, what is the maximum ...
1
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1answer
216 views
Adjustable 9v - 15v 1.5A DC Switching Power Supply from 6 D batteries
I am starting a project that needs a way to adjust a 9v supply to anywhere from 9v - 15v at 1.5A. The power is coming from 6 D cell batteries so the voltage will drop as the batteries wear down.
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