Dc Definition and 1000 Threads

A DC-to-DC converter is an electronic circuit or electromechanical device that converts a source of direct current (DC) from one voltage level to another. It is a type of electric power converter. Power levels range from very low (small batteries) to very high (high-voltage power transmission).

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  1. M

    Converting Mini Split AC to DC Power w/ 48V Motor: Expert Advice Needed

    I want to convert a mini split air conditioner from ac to dc so it can be powered by a 48 volt battery bank and rercharged by a solar panel and wind turbine hybrid system.(hybrid charge controller) I want to replace the ac compressor motor to a 48 volt brushless perminent magnet motor of...
  2. H

    DC charging circuit Calculating I, V, and Z?

    I have a few questions on DC resonant charging circuits. The circuit only has a few practical applications, most noteably Radar and there is very little info online about it. If anyone could help, I would be very thankful... 1. What would be used to calculate max current in the circuit...
  3. B

    DC Motor Wires: Current Flow With/Without Insulation

    http://img23.imageshack.us/img23/6131/17743493.jpg One thing bothers me... If we have a wire with NO insulation, and we make a loop like in these 2 examples. Connect those ends to battery. Current runs from + to -. Now, will the current behave like in A or in B(no insulation). I know...
  4. J

    RLC DC Transient over-damped response

    Hello All, I have a bit of a problem with a series RLC circuit with no supply voltage. In the process of actually solving the second order differential equation for the voltage across the capacitor I have lost a handle on what it actually represents in terms of the circuit. I have attached...
  5. J

    How to reverse the action of a small 12V DC MOtor

    Hey Guys ! I am working on a personal project, and I was hoping you could give me some help and advices. I am looking for a tool/device that would reverse the action of a small 12V DC motor (make it operate clockwise and then counter-clockwise for example). And I was also wondering what kind...
  6. S

    Can LC Oscillations Be Generated Using a DC Source?

    Homework Statement Suppose we have a circuit with the inductor, uncharged capacitor, ideal battery with emf E all in series. At t=0, the circuit is switched on. The following takes place sequentially: 1. Current at t=0 is max. Battery charges capacitor, current decreases. 2. inductor...
  7. R

    What Will Happen to a Lamp Connected to AC & DC?

    Hi, I am just thinking and i got doubt that if one wire carries AC(3V) and other wire carries DC(3V) and on the other side if you conntect together followed by a diode and last with one lamp. What will happen in that situation to lamp.
  8. T

    Engineering Current trends in the design procedures of DC chopper circuits

    Hi everyone, my name is Tics and I need some help with regard to DC choppers. I'd like help in addressing the following: an overview of DC chopper design in terms of application and technical requirements; Design procedures for DC choppers; DC chopper topologies; A discussion of...
  9. J

    Can One Secondary Transformer Power Multiple Outputs on a DC Power Supply?

    I've been looking ahead in my textbooks and reading some stuff online, and there's some things I'd like to know about DC power supplies. The DC power supply we have at school has 3 independent outputs, 2 variable and one fixed. How would they be isolated from each other like that...
  10. S

    DC Motor / Current Control and Torque/Speed Relationship

    Hello, First time posting here as I havn't been able to find a suitable answer to my question to help me understand some issues I am having with DC motors. I am trying to calculate the maximum speed and acceleration of a dc motor being driven by a current source with a known inertia. I...
  11. C

    DC Permanent Magnetic Generator Help

    Hey guys, I want to build a DC Permanent Magnetic Generator that will generate electricity which I want to pass through a Bridge Rectifier to produce DC electricity which I'll store in batteries or I want to pass it through a power inverter for domestic use. Is this possible? I was...
  12. E

    Analyzing a 500V DC Machine for Vehicle Motion

    Homework Statement Considering a 500 V, 50 HP DC machine with the following parameters, Kv=1.8 Vs/rad, tau=50 mS and ra=0.07 ohms; Bm=0 p=1.2 kg/m^3, A=2.3 m^2, Cd=0.370, Crr=0.0106, Wveh=1000 kg, g=9.8 m/S^2 Assuming the machine is connect to a single quadrant converter with a switching...
  13. K

    Engineering Braking a Separately Excited DC Motor: Calculation and Analysis

    Homework Statement A separately excited DC motor with 220V, 970rpm, 100A and Ra=0.05ohms. It is braked by plugging from an initial speed of 1000rpm. I need to calculate i)the resistance to be placed in the armature circuit to limit braking current to twice the full load value, ii)the...
  14. A

    DC to AC conversion and power relation

    I saw this "AC anywhere" last week and was wondering how it works? How we can get 230 volts out of 12 volt DC supply? Isn't it drawing more power from less? [Below is the description of the Device which I'm discussing about] Running out of power is a thing of the past with the AC Anywhere...
  15. R

    Proving DC Current Loop Does Not Radiate w/ Lienard-Wiechert Potential

    Homework Statement Hi guys, on chapter 14 in Jackson's classical electrodynamics, problems 24 asks to prove that a dc current loop does not radiate, starting from Lienard-Wiechert potentials for the individual charges q. The distance between them is \Delta. We should move to the continuous...
  16. B

    Creating a Synchronized Pulsed DC Speed Control Circuit for Brushless DC Motors

    How would one go about creating a speed control circuit for a brushless DC motor? I need two circuits to pulse DC in one direction, pause, reverse polarity, pause, and repeat. And I need the two circuits to be synchronized. I also need them to be opposite of each other in there polarity.(when...
  17. A

    DC Linear Solenoid: Generating 60 Amp Current for Robotics Project

    I am using a DC push-type solenoid as the mechanism for shooting in my robotics project. I have to use 12V DC supply and have to shoot TT balls for distances upto 3-7 feet. The solenoid specifications suggest that it requires 60 amp current. How do i generate this?? Thanks in advance
  18. C

    AC to DC Converter for Electrolysis hobby

    Hello All, I am interested in constructing a small Hofmann apparatus for electrolysis (as a hobby), like this kind: http://en.wikipedia.org/wiki/Hofmann_voltameter" I am confronted with the choice of either using a bunch of 9V batteries, or some kind of AC/DC rectifier. As I am a...
  19. J

    DC conductance in the presence of a time-dependent electric field

    I calculated the DC conductance of a 2DES in the presence of a time-dependent (periodic) electric field using the Boltzmann equation some time ago, and I'd like to verify the results numerically. Ideally I'd like to perform a computation along the lines of a recursive Green's function...
  20. Y

    Understanding AC and DC: Key Facts and Differences

    I just wonder if the readers here realize a couple of things. 1. Basic Ohm's law is different than the Laboratory Ohm's law. 2. If a DC voltage is applied to a resister, an AC voltage is always generated across the resister. I hate to use 'always' but as far as I know it is this way...
  21. B

    How Can I Increase the Amperage Output of an AC to DC Converter?

    hey guy I was wondering if there was any way to increase the amperage output of an ac to dc converter, it is a 120v ac input that outputs 13v dc at 3.42 A. is there any way to boost this output? P.S. Ya'll are the best, This is by far one of my favorite places to be on the web. kudos on a job...
  22. D

    Urgent Search for 12V DC 1/3 RPM Motor for Telescope Mount Design

    quick and urgent:I need a DC MOTOR hi I'm designing a telescope mount and I need a motor which has less than 1 rpm I think I'm going to need (( 12 V DC 1/3 rpm )) please if you can help me !
  23. F

    PWM Circuit and DC motor problems (for NYE ball drop project)

    Hi all, This is my first time making a somewhat complicated circuit, with the help of an online schematic. (http://www.dprg.org/tutorials/2005-11a/index.html ) My goal is to make a New Year's Eve ball-drop, which has a motorized controlled-release lit-up ball (on a separate power...
  24. L

    Engineering Understanding DC Motor Operation

    I've been studying the concept of operation of DC motors and there are a couple things which I'm having trouble with. When the rotor is rotating, there will be "cutting" of flux and according to Faraday's law an emf is supposed to be generated such that it opposes the change in flux producing...
  25. S

    How to find out the right DC motor

    Hi guys, I am a bit confuse on how to calculate the power of the motor, the torque and the speed of the motor shaft + how to find out the rpm. Basically, i want to buy a motor which will be able to travel 100miles with a min speed of 55mph and have a total load of the vehicle of 600kg. if...
  26. R

    Converting DC Circuit to Ultra-Rapid Pulses - Help Needed

    Need help with circuit problem---I need to convert a simple dc circuit---approx 3 v---into pulses---perhaps as rapid as nanoseconds in betw pulses---however not yet sure of freq----also dc polarity would remain the same. Is there any component or device that could act as an ultra rapid on off...
  27. W

    What is the relationship between the DC and AC ratings of capacitors?

    Hello everyone, I have a few microwave caps rated at 2100 Volts AC and was wondering about their DC rating. I've heard that the DC rating of AC caps is usually 3-5 times the AC rating which seems to make sense but I'm not absolutely sure... If someone could please confirm or deny this I'd be...
  28. R

    Weird Current Flow in DC Circuit

    Edit: Nevermind, I figured it out! I jumped the gun in making this post. I'm doing another problem from Schaum's Outline: Basic Circuit Analysis. The problem, #3.24, and its solution are found in this...
  29. U

    Low RPM, high torque DC motor help

    Hey folks, I have been thinking about doing a little hobby project for while, but didn't have the right knowledge to do it until now. Basically, I need a relatively small Low RPM, high torque DC motor that can be controlled by a microcontroller. I'm using the arduino duemilanove and have...
  30. S

    Is there an Optimal RPM for a DC generator?

    Is there an Optimal RPM for a DC generator?? I would like to ask if there is an optimal rpm for a DC generators? Or the faster it rotates, the more power it generates? The specification of the motor is as follow: http://www.mitsumi.co.jp/latest/Catalog/pdf/motorav_m25e_11.pdf
  31. M

    Electricity (DC) and magnetism

    When current (DC) passed through a wire it creates a magnetic field around it, right? But if you placed magnets around that wire would they interact with the electricity flowing through the wire? If so, to what extent?
  32. R

    How to maintain a 12V 150 RPM geared DC motor's torque in all speeds?

    Hi everybody, This is my first message here and it looks like an awesome forum! :smile: I have a 12V geared DC motor and i am having a hard time figuring out how to maintain it's torque in from speed 0 to 150 RPM.. I know about PWM and figured it's not going to do it.. I am looking...
  33. N

    SI Notation for Direct Current and Voltage Direct Current - Correct Usage?

    Hi, Looking for the SI Notation practices for Direct Current and Voltage Direct Current. We commonly use DC and VDC, but I wonder if that's correct per SI. I've looked through several guides and pdf's of SI Notation, and haven't yet been able to find the answer. Any help you can...
  34. J

    How to convert DC to AC for auto sensor?

    Can anyone help me convert 12v DC to AC for the purpose of measuring fluid permittivity in real time, automotive application? I'm new to PF and limited experience, so all the help/details you can provide are greatly appreciated.
  35. I

    Speed/torque curves for brushless DC motor

    Hi everyone. I came across this site yesterday during some targeted Googling and thought I'd give it a shot. I have a basic question about speed/torque curves for brushless DC motors. I would like to compute a speed/torque curve for a small three-phase brushless DC motor that I have. It...
  36. B

    Test an Ammeter: 24V DC 100A Loads

    How can i test an ammeter with ratings 24V (dc) 100 A with any load? This is just to check whether the ammeter works in the defined range. What kind of source should i connect to get a current of maybe 25 or 50 amps.
  37. M

    Help Needed: DC & AC Testing with DMM on 120V Peak AC Signal

    if you connect a DMM across a 120V peak AC signal what should be your output in DC mode??
  38. B

    Transform Your Winch: How to Convert an Electric Winch from 12V DC to 120V AC"

    i have an electric winch that runs off a 12v dc car battery and i want to run it off of 120v ac house electric current. is this possible, and if so how would i do it? thanks for any help
  39. K

    How Long Does It Take to Charge a Battery Using a Rectified AC Supply?

    Homework Statement Hello, I have one hard exercise, that I can't do. Sorry for my English, it's not my mother tongue, but maybe somebody could help. To charge a battery with direct current I, it takes t=8 h. But they didn't have a DC supply, so they charged it with AC, that was rectified...
  40. L

    Just curious how electric motors work, specifically DC motors.

    Just curious how electric motors work, specifically DC motors. I have some questions i would like to understand better. do the windings of a motor determine the required voltage to power it? Can a 110 volt ac motor be powered by a 12 volt dc battery without an inverter? Can a 110 volt...
  41. A

    DC Equivalent Circuit: Resistor vs Cell

    please could you tell me that ,In dc equivalent circuit the resistors are replaced by cell.why is it so?though the resistor gives voltage drop where cell provides a emf then how does these are equivalent? thanks.
  42. M

    Rotary Encoder Pulses to DC voltage

    Does anybody know a good way to take the pulses from a rotary encoder and turn them into a DC voltage that would go up for clockwise turning and down for counterclockwise turning? I have the A and B pulses from the encoder, and that's about it as of yet. I also have these chips...
  43. K

    Effortlessly Convert AC to DC for Your Cushman Scooter | Tips and Tricks

    Hello, I have a small 9hp engine with electric start and a stator that puts out between 5-18 volts ac, it only has one wire coming out and would like to convert it to dc to run lights and charge my battery on a cushman scooter. any help would be appreciated...
  44. I

    How can i pulse a DC current at a rate of Ghz

    how can i "pulse" a DC current at a rate of Ghz i need to pulse a dc current through a circuit in at 2.45Ghz. astable multivibrator style How might i go about doing this
  45. E

    Find the Perfect DC Motor for Your Robot: Tips and Tricks for Calculating Torque

    Hello I need a little help here. I need to pick a DC motor to be used on a robot. I'm trying to calculate a minimum torque the motor should be able to produce, but I'm a little confused. torque = Force * distance = Mass * acceleration * distance (Ignoring moment of inertia created by...
  46. O

    Resistance of a capacitor and inductor in a dc circuit

    Homework Statement From my Basic DC electronics text. 2 questions, multiple choice, but I seem to be able to talk myself into several of the options. I've combed the book thoroughly, and humbly come to you folks in sincere desperation. The resistance of an/a Inductor/Capacitor in a DC...
  47. H

    What is the DC Resistance of a Silicon Diode at 10 mA?

    Homework Statement The dc reistance of a silicon diode for a current of 10 mA is closest to: Homework Equations Really not sure. The Attempt at a Solution Not sure where to start, this goes with a lab I just completed but not sure if this problem directly correlates to it.
  48. T

    Why Does a Resistor Show Different Values in AC and DC Measurements?

    Homework Statement If possible, find reasons why the resistance of a resistor may have a different value when measured with a sine wave signal (a.c.) than when measured with a d.c. (dirrect current) source. Homework Equations The Attempt at a Solution Please correct me if anything...
  49. F

    Calculation of torque of a DC motor

    Hi everyone, Im currently doing my final year project and I need to calculate the torque of a DC motor so that I can replace it accordingly by another motor. Here are the motor's specification : 400V, 50Hz, 6poles, 200kW, 1400rpm, 371A Can anyone please help me sort this out. regards...
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