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)
6
votes
1answer
112 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?
1
vote
1answer
56 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
69 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 ...
1
vote
2answers
76 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).
...
-1
votes
3answers
206 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 ...
0
votes
1answer
77 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
votes
1answer
96 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 ...
3
votes
1answer
265 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) ...
0
votes
2answers
136 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 ...
1
vote
2answers
96 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
votes
1answer
120 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.
...
10
votes
3answers
343 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
votes
0answers
101 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
votes
1answer
176 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 ...
1
vote
2answers
511 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
296 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
355 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
547 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
119 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
514 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
6
votes
3answers
3k 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 ...
1
vote
3answers
258 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
vote
1answer
196 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.
...
6
votes
3answers
1k views
Should I isolate grounds of an isolated DC/DC converter?
If I use an isolated DC/DC converter, when designing the PCB, should I isolate the ground of the input and the ground of the output as shown below?
I've never isolated grounds (except for AGND and ...
6
votes
4answers
547 views
MC34063A: Why am I overclocking this chip?
I've decided to get some experience with DC-DC converters and I've obtained an Onsemi MC34063A DC-DC converter. From documentation I've got the datasheet, the AN920 application note and the Excel ...
3
votes
2answers
360 views
What must be the minimum input voltage of a series regulator?
I'm designing a series regulator. I need 3.3V in my circuit, the circuit has 5V and 9V available in it.
What should be the minimum input DC voltage in a DC series regulator in general case?
In this ...
2
votes
3answers
129 views
Can a dynamic circuit extract all energy from an ultra capacitor?
I understand that the energy extraction from an ultra capacitor drops the voltage to the point where the load can't function? But, is it possible to create a converter that can continuously present a ...
1
vote
2answers
105 views
what is the simplest set up for detecting ions?
I try to detect a flow of positive charged ions. These ions produce an electrical current in the order of 10^-12 Ampers. My question is that, what is the simplest set up for detecting these ions?
...
2
votes
2answers
608 views
Need help with a DC-DC converter using a MC34063
I'm trying to make a DC/DC converter from 12V to 5V using a MC34063. I found an old cell phone car charger and removed everything and set it up on my breadboard. I'm getting 5V out but only 0.12A. ...
11
votes
4answers
1k views
Why do smaller loads require larger inductors in buck regulators?
The MC34063 Application Note lists the equation for calculating minimum inductor size as follows:
$$L_{min} = \frac{V_{in} - V_{sat} - V_{out}}{I_{pk}(switch)} t_{on}$$
But this implies that as ...
0
votes
1answer
246 views
Building a simple switching regulator for DC12V -> DC5V
I want to build a circuit that provides USB power from a 12V battery (lipo or car battery).
I have an iPad that draws 2A from its charger: So I'd like to get up to 10W output.
What's a good choice ...
0
votes
1answer
276 views
How might I wire a split pi converter to transistors as to maximize output voltage?
I was looking into various dc-dc converter designs, and I was interested in the split pi converter.
As a start, I just want to maximize the output voltage. I know in theory, the output voltage could ...
0
votes
1answer
178 views
Transmit high current with low voltage on a lightweight system
I have a moving system at 20meters from, say, a base station. The system consumes more or less 200W at 12V. I used until now a battery to power the system. The main drawback is that I have to recharge ...
2
votes
3answers
320 views
Cost effective way to convert 12v DC to 7.6v DC @2A
I'm working on a hobby project that involves continuously powering a 5 watt handheld radio for long periods of time off a 12v automotive electrical system (in reality the input will be more like ...
2
votes
2answers
227 views
Suggestions for DC/DC converters with digital control
I am under quite some time pressure and I need to put together a document about how several DC/DC converters (preferably buck) with digital control compare to each other. I am pretty clueless, I have ...
12
votes
5answers
3k views
What is causing large oscillations in my DC/DC boost converter? Is this ground bounce or some other effect?
I designed my first PCB for a DC-DC boost converter only to find that it produced very noisy output. The design is based around the MIC2253.
Here's a schematic:
Although my circuit allows for ...
0
votes
0answers
103 views
DC-DC Step up circuit [duplicate]
Possible Duplicate:
Best way to produce 50 VDC, 20 mA from 5 V
I want to boost a 5v input to +/- 12 or +24V output. I was wondering how to design the converter circuit and what parts can be ...
2
votes
2answers
158 views
Low voltage 2 channel stereo analog switch
I am looking for a ultra low voltage 2 ch stereo analog switch.
I have two headphone audio sources that I need to switch between.
It is very important that the chip can run of a 1.2v rechargeable cell ...
7
votes
4answers
1k views
Least expensive way to boost DC voltage
What would be the least expensive way to boost a DC voltage?
The aim is to convert 1.2 V/1.5 V (from an AA/AAA cell) to 3.3 V to power a small 8-bit microprocessor, like Atmel ...
11
votes
2answers
337 views
Negative Inductance and Cascaded DC/DC Converter Instability
I'm trying to debug a pair of cascaded DC/DC converters and have ran into a brick wall. The local FAE said that it is probably something to do with "Negative Input Inductance" on the second converter ...
1
vote
2answers
206 views
2 SMPS - Does it make sense?
I am following up on my earlier question. I am trying to build a very clean 5V and 3.3V supplies. I have asked this question and got several very good answers, we designed it and it will come back ...
3
votes
5answers
2k views
Ultra low noise power supply
I am trying to design an ultra low noise power supply for my sensitive circuit. The supply will provide 5V and 600mA. (Worst case, 200mA typical). My input voltage is 2V to 4V. My ripple target under ...
3
votes
2answers
200 views
Why are these similarly spec'd DC-DC converters an order of magnitude different in price?
I need to drop ~12V to 5V, but I'll be pulling somewhere around 5-8A. Looking for DC-DC converters I found these (plus many even more expensive parts), but these model plane UBECs are a tenth of the ...
5
votes
4answers
439 views
I want to build a DC powered computer, what are the gotchas, where are the parts?
Google builds its servers with a Battery in the box so that they don't need a UPS. I'm wanting to do the same, but I'm wondering what all the gotchas might be for doing this, and where I'll find the ...
2
votes
1answer
352 views
Current booster DC-DC 300mA - 900mA
I have a source of power which can provide up to 300 mA at 1.5 V DC, however I would like to power a circuit which uses 900 mA at .5 V DC. What would be the easiest way to do this? If it was AC I ...
8
votes
4answers
510 views
Designing 12V -> 0.1V 100-500A DCDC
I need to build 0.1V@100-500A power supply - and I wonder what's the best way to approach this task? I guess here are not much specific IC's suitable for such DCDC... Should be current-stabilized, 10% ...
4
votes
2answers
845 views
Calculating Power Loss in Switching Power Regulator?
I am new to the construction of DC/DC power supplies (still a university student) and have built basic supplies using simple linear voltage regulators. I have recently discovered the world of ...
4
votes
2answers
210 views
DC/DC isolated supplies in series for higher voltage?
Can I chain two isolated DC/DC supplies together for a higher output voltage? (Say, a 48V and a 12V to get 60V?) They'd be fed from the same 24V DC source.
I've asked a related question before ...
5
votes
3answers
3k views
Calculating size of cap & inductor for buck convertor
What is the idea of choosing inductor & capacitor value for buck DCDC convertors (no specific part number, in general)?
I've tried random one with low resistance, and it kinda works, but want to ...
4
votes
2answers
978 views
Arduino and 5A 12Volt driver
I want to drive a 5 metre strip of 300 5050 SMD LEDs. It comes with a 5A power supply but I don't know what the rating are for these LEDs.
The thing is I want to be able to change the voltage using ...
