Dc Definition and 1000 Threads

OK. On datasheet of transistor 2N4401 there are many DC current gains (hFE). Which one is useful. I want to use it over 5V and 60mA.

I'm doing a project where I need to hand power one small, dc motor (1.5-12V) and charge a 1F 5.5V super capacitor, and then use it to drive another small 1.5-12V dc motor. Does anybody have any suggestions for motor specifications or circuit elements that will help me get the most efficiency...

I'm building a hybrid car for my kids. I'm up to speed control and hitting a few hurdles. The set up is 4 x 12VDC motors, one to each wheel through a reduction gearbox. I've wired them to a single bus, and have used 4 standard relays to deliver forward/reverse. I have tried varying the speed...

Will this circuit work for maintaining a dc bias on the capacitors? I am under the impression that there is +4 v at point A; even if an emf charges and discharges the capacitors. I worry that current will flow into the battery.

I recently built a rather crude SMPS using two very powerful IGBT's and a SG3525 and IR2110 driving circuitry. It's a half bridge and even though it's unregulated the output voltage is quite stable , dropping only few volts as the power output goes up to 1KW and some more volts after that.but...

Hi there, I m a beginner in Analog IC design field. Currently, I have a project which is to design a high sensitivity rectifier by using Synopsys simulator. However, I m stuck in the beginning part which is the DC biasing of MOSFET transistor. The design specification as below: Technology ...

I recently bought a DC power supply online to perform experiments that require electricity. I am not an expert with electricity so I have a few questions about it. It has a maximum of 10 amps and 30 volts, and both values are variable, however it does not show me the value of the current unless...

Hi, I am thinking of ways to detect when an electrical device is turned on and off without actually touching or modifying the existing circuitry. More specifically, I have a hand held device powered by 2 x 9V batteries and with 2 electrodes connected through leads and plugs to sockets on the...

Homework Statement A permanent magnet DC motor has an armature resistance of 0.4 Ohms. When a voltage of 110 V is applied to the motor it reaches a steady-state speed of rotation of 126 rad/s and draws 39 A. (a) Find the power loss in the armature (b) the power input to the motor I really...

Hello everyone, I am designing the power system of a new circuit. It will receive an analog video signal and then be able to split that video signal to multiple outputs. I would like to have multiple ways to power the circuit depending on the application. One way to power the device will be by...

How to get pure DC from an ac whose voltage or amplitude is increasing by time until it reaches a particular fixed value and then drops to zero

Hello everyone, So, i have a big test tomorrow and my professor said i should study the DC level in Fourier transform , in the frequency domain. So, i did a little research and found out that the dc level is the percentage of the time a signal is active, and that's all. Can't see how that's...

Can anyone explain me in simple words what is quescent point and what is shows 2- what is ac and dc load lines what they represents actually and what is difference between ac and dc load lines

Any one know circuit inside DC boost step up pulse generator? I have this one buy from ebay 400Kv type,i want to know how this work by circuit inside.. I had googling and not found result.. Please help me..

hi dears i need your advice. i wand to produce high pulse dc current in below described circuit: - power source is lithium battery 3.6 v (limited output current, maybe 1A) - load is resistor 0.01 ohm - current by value of around 50 A during 0.001 second need to be passed from the load. -...

4Use the power to sum formula to simplify the expression $\frac{\sin\left({3\theta}\right)+\sin\left({5\theta}\right)} {\cos\left({3\theta}\right)+\cos\left({5\theta}\right)}$ The answer is $\tan(4\theta)$ $$\sin\left({3\theta}\right)+\sin\left({5\theta}\right)...

Homework Statement DC steady state circuit analysis: Consider the circuit shown below. The switch shown in the problem opens at time t = 0 seconds. If the circuit is in DC steady state at , find values for iL(0-), iL(0+), i(0-), i+, Vc(0-), Vc(0+). There is no RL or RC analysis to be performed...

Hi Guys I'm hoping someone can help me out with a problem?? I have just started learning about DC motors and I have hit a wall on how to solve the following problem- Q.The output of a series d.c. motor when connected to a 230V supply and running at 1320rev/min is 3.8kW. The supply current for...

Homework Statement See , in the methods of improving the commtuation , one of the method is using interpoles now what I think that interpoles aids commutation by nullifying the reactance voltage in the conductors. Though this point is mentioned with the working but it is also mentioned that...

If I'm not mistaking , all DC and also universal motors have a brushed commutator not a slip ring commutator because the rotor wires need to keep the same current direction as they rotate pass the same magnetic stator pole. so the only DC motor which could operate on slip rings is a homopolar...

Consider a closed electric circuit consisting of a conducting straight rod connected to a DC voltage source switched on. In steady state the current flowing through the conductor creates a steady magnetic field around it with magnetic flux lines that can be represented as concentric circles...

Take the following circuit (capacitor initially not charged) : I am trying to solve for the current everywhere as a function of time. I set up the following equations (are they right ?) : Then, any way I try it, I end up with some messy integrals. Even using wolfram alpha to get those...

If an ideal inductor is connected directly (no resistor present) to a DC voltage source, why does it behave like a short-circuit at time t=0? If voltage across an inductor is related to the change in current (i.e. di/dt), then shouldn't the voltage across the inductor be very large at time t=0...

Homework Statement My group and I have to design a lap wound dc motor. Maximum of 12 volts and 5 amps. Must have no more than two poles. The aim is to achieve maximum efficiency. I've created this excel spread sheet to calculate the gauge of wire we need and the type of magnets. Also how...

Hello I was wondering if you could advise me on the following. I am undertaking a personal project at home (mainly mechanical in nature) whereby I require the L293D H-Bridge to connect to a 12 V DC motor. I'm using a PIC 16F877A microcontroller. This microcontroller has a 5V output. The...

I have a DC source. then I connect a capacitor from the +ve to ground. if all connection are made from ordinary , copper for example, wires then electrons flow from negative to positive terminals.So electrons from the negative side of the capacitor would flow to the positive. I wonder what...

Hello, I am building a large DC motor for a Go-kart. I have a question: How would I know how much voltage and current (the maximum values I can use) I need to make the DC motor work and spin? I'm guessing the armature size and the winded wire's length depends on how much voltage and current...

Homework Statement Homework Equations While equations should be unnecessary to solve these questions, I am not sure if I have done so properly. The Attempt at a Solution Well, I placed my answers on the paper already. I am unsure about the potential difference between 12V and 5V, as since...

I am trying to understand this curve; it is AC Power vs. Field Current of a DC Generator. I am not sure what its significance is? What it's telling me? Can someone please explain it to me? See attached image. BTW... Pac = AC Power If = field current Poc = open circuit...

Hello, I would like to start building a simple DC motor Go-kart, but I would like to build my own DC motor for it. A simple one that can make the car move. I know how DC motors work and I understand the physics of it, but I'm not sure about some things: - Are all DC motors (large or small) the...

Given a simple DC generator with a single loop in the presence of a magnetic field such as the one below, typically, the analysis involves how each rectangular loop's terminal ends up on opposite sides of an armature housing each of the coils. The analysis is fairly straightforward to then...

Suppose a motor is run at 1500 rpm and field rheostat is at minimum position (say 10Ω). Then the field rheostat resistance is increased to 100Ω and the speed obtained is 1700 rpm. Now the motor is shut down and started again. Will it now run at 1700 rpm? My logic: No it won't, because: the...

A battery of constant voltage is in series to a conductor that is placed in a changing magnetic field over time, inducing an EMF with a polarity as indicated in the circuit as "Induced EMF(1)", both the battery and the induced EMF(1) are in series as the input voltage to the DC converter, the...

Project : a solar panel powered LED light (with built-in storage battery) with the house facing north (in Canada). Story : The kit is bought at Costco. The solar panel is small (but it provided a 20 ft cable) and separate from the battery and light. The light (motion and light activated) is...

Homework Statement In the given DC circuit, while switches S1,S2 are open, conductor C1 is charged with Q10, and conductor C2 is not charged. After the switch S1 is closed, through conductors flows the amount of charge q1=40µC. After the switch S2 is closed, through conductors flows the amount...

Hi at all, I need to convert a DC signal ranging from -2 V to +2V to a AC signal with an amplitude of approximately the same voltage at let's say 1 MHz. The frequency can vary but has be higher than 10 kHz. I looked for PSW inverters but didn't found any suitable. Our intention is to record a...

Homework Statement A direct current i=10 A flows in a long straight round conductor.Find the magnetic flux through half of the wire's cross section per one metre of it's length. Homework EquationsThe Attempt at a Solution I have spent quite a while thinking on this problem but I can't think of...

Hi, I have a question about LC series oscillators. Specifically when a DC supply is applied. Solving the differential equation for such circuit using as initial conditions at t=0 that Vc=0 and I=0 I get as a solution that the circuit oscillates and the voltage across the capacitor has an...

Im looking to simulate a lap wound permanent magnet brushed DC motor and am looking for advice on the best program. I've carried out some calcs in excel and wondering if I can simulate the motor in solidworks or Ansys to optimize placement and size of components in order to maximize efficiency,

From the abstract: "Experiments show that Poynting vector is just a mathematical definition in the DC case. Since it does not form real energy flow, there is no transmission of electromagnetic energy flow from the exterior to the interior of a metal wire. Therefore, DC power is transmitted...

Hello every one umm... I am very new at all of this and I need your help. I have a project that I am working on and it involves a 120V 4.5amp DC concrete drill motor and my bike. I am using this motor because it has enough torque and I just got kinda bored lol anyway, I am having a bit of...

I am creating a scale model wind turbine using a DC motor as a generator and would like to predict the motor response analytically. Generally speaking, the flow will spin the rotor (as in the turbine's), which will spin the motor, and then there will be what I'm calling the motor response, and...

Here is my misunderstanding , for the example let's ignore resistance losses , say i have a infinite length of coil , and an infinite strip of magnets passing through that coil, each magnet separated by some distance from the next one , the strip of magnets move through the middle of the coil ...

Hello, I am an engineer working on a project and have several questions. I believe I have the answers I need, but this forum is such a great place to confirm my thoughts. I am installing USB charging ports on a luxury coach bus. There will be a charging module installed at every pair of seats...

I am making a small solid state tesla coil. I have the secondary coil, toroid and primary coil but am not sure what to do for a control circuit. I was planning on using two 9 volt batteries for power. Would a DC to Pulse Width Modulator work? This is the one I was thinking of -...

Homework Statement In the following circuit I need to find current I1 if the given parameters are E1=0V,E2=15V,E3=60V In the second case, given parameters are I2=100mA,I3=40mA,E1=30V,E2=E3=0V In both cases, R2=R3=R4=R5=300 ohm Homework Equations Using reciprocity theorem for DC circuits. The...

Homework Statement The book says that "the induced voltage E_a can be found by measuring the open circuit voltage at the armature terminals" Homework EquationsThe Attempt at a Solution But isn't there a voltage drop across the resistor so that they can't be equal? or is this ignored

When current flows through the armature winding of a dc motor, what exactly happens in there that produces the torque? Is there a force due to the interaction between two magnetic fields or Lorentz force acts on the conductor electrons? Basically, why does motoring effect take place? Is it due...

After bearing failure of 24V, 15A dc motor. We change the bearing of the dc motor. But after changing it the motor is running forward/ reverse but there is no control over the speed. Where is the problem? Is that in the techo or drive card? Any body please help. Helping in highly appreciated...

If a fusion reactor could be constructed that runs on Li-7 and hydrogen, and if the energy produced by that reactor where extracted with a direct charging setup, like in a nuclear battery emitting alpha particles, the voltage produced would be the stupendous voltage of 8 mega volts. Now, how do...