i am being told trying to make a self winding clock means ppm when this is a self winding clock
https://en.wikipedia.org/wiki/Self_Winding_Clock_Company
and this is a self winding watch
https://en.wikipedia.org/wiki/Automatic_watch
i hope someone speaks on my behalf to be allowed to...
In Simulation of transformer and electrical motors in software like ansys maxwell we usually have to model conductors, but does it matter how to draw them?
I use Ansys software for finite element simulations. Maxwell, Simplorer, RMXpert and other toolboxes. but I always have a doubt on how to...
I’d like to build a high speed generator using a diametrically opposed magnet. I’m asking if when using a diametrically opposed magnet rotating on a shaft if the generator coils can simply be a continuous wound loop around the magnet like a electro magnet is wound therefore only requiring one...
I have been looking at 'Horology' forums but they all seem to be more about buying watches and less about the way they work and about mending them. (Money money money). I sort of hoped that good old PF might have some ideas about my problem.
When I was 21, my parents bought me an Omega...
Hello,
I usually wind induction motors. I found folding their insulation papers are so boring to me. So, I would like to make a machine that eases my job. Please see the attached file. The paper's dimension would be something like 80cm x 120cm. This machine must be able to fold the yellow areas...
All illustrations of direction of force in motor has this form.
For the following specifically the rotor. I'm confused where is the direction of force. It uses winding and there seems to be current and force in every side of the winding (applying left hand rule). So where does the principal...
I saw briefly that the Riemann tensor can be obtained via Stoke's theorem and parallel transport along a closed curve.
If one does add winding number then it can give several results, does it imply that this tensor is multivalued ?
The problem seems to be easy but i don't get the correct answer.
a. The current in the field coils. The net resistance of Rf = 106 and Rr = 5.9 is
## Reff = \frac {(106 * 5.9)} {(106.9 + 5.9)} = 5.54 ##
## \frac { 120 - E} {5.9} = 4.82 => E = 91.562 ##
## If = \frac { 120 - 91.562} {106} =...
I have an older 12 volt battery-charging 1979 Sencenbaugh wind generator that I am testing. It has an 3 phase alternator with a field winding that must be excited, as opposed to the newer "permanent magnet" alternators. The manual says that 60 watts maximum should go to the field winding...
I need help building a charging system for a motorcycle that has been converted to a 12v DC EFI system (formerly carbureted with a CDI ignition). The original full wave system was designed specifically to produce high voltage for the ignition system (32 gauge wire with thousands of turns). My...
I am testing an ac armature ohms all seem ok except for to spots 180 degrees apart on opposite side the ohms are higher than the rest when measuring from bar to bar. I do not know from the readings if I have two opens or just one. To me it seems I have no shorts just opens. I made diagram of...
1) B = Φ/S = (4.2*10^(-3) Wb)/(2.5*10^(-3) m^2) = 1.68 T
2) Using electrical steel magnetization curve given in the textbook: magnetic field strength H corresponding to magnetic flux density 1.68 T is equal to 6000 A/m.
3) L is a length of the middle magnetic line of the core (Fig. 2).
L =...
Hi,
I am going to wind an tapped toroid inductor for a LCR circuit in an equalizer.
I have calculated the number of turns I need for each winding.
This is my first time winding an inductor so I need to get some things straight.
What to do with the 10 kHz tap, should I twist a wire with the 12...
Hi Guys,
Single phase capacitor start induction run motor keeps running even after start capacitor is disconnected by centrifugal switch. But in practice, table fan motor stalls and hums when I disconnect starting capacitor when fan motor reaches full speed.
Why one phenomenon works in certain...
Alright the attached picture has the two physical layouts I'm considering for the chuck, however I'll admit that looking at the math involved to determine the construction of the individual magnets and a knowledge gap in how best to manipulate the construction of such a thing to have the...
Conceptual question here. Not really positive if it should be asked here or in general physics...
In U.S. grid power supply could the secondary winding in a step-down transformer providing split phase power be grounded at any point in the winding?
Instead of calling the center tap neutral, if...
I want to make a dc generator and not sure my design will work. I will wind the coil on a donut shape disk and put 6 rectangular magnets on a disk rotor with North Pole face the coil. Please see attached pictures. Will this design works or have problems? Can I have one continuous coil or I...
Are the manual winding machines capable of winding wire in two directions by just turning the crank?
left to right, right to left, left to right etc...
I want to neatly wind wire on a coil not just wind it down the middle and hope the wire falls into the right place.
Thanks in advance!
Hello,
I'm boy who suddenly been strucked by curiosity on how hand crank generator works and i watch and read some of how to create one, specially this one on youtube:
and i want to create one but i don't have a 3D printer, but i saw some alternative but as i do/design my own coil based on...
Hi there, i have a three phase synchronous generator that is powered by a 1/3hp electric motor. I am having difficulty calculating the inductance of each phase of the stator winding when it is at full operation. I will give you some of the specs of the alternator. The rotor has 12 poles, with an...
Hi again, another question.
Please see the schematic below. It shows a wye-wye(n) with a delta tertiary winding. So this delta winding is inserted here so that we can achieve amp-turn balance with the zero sequence currents flowing on the secondary side.
I know that zero sequence currents...
Homework Statement
A half wave rectifier circuit has a transformer inserted between the source and the remainder of the circuit. The source is 240Vrms and 60 Hz, and the load resistance is 20ohms.
1) Determine the required Turns Ratio of the transformer such that the average load current is...
I don't understand how this is possible.
This is a rather large transformer in a stereo system amplifier. The transformer is a simple step-down with 120V mains primary to a center-tapped secondary providing both 38V and 76V.
According to ohm's law, at 120V this thing should draw about 85 amps...
I have a transformer that has 120/240 on the primary,but the secondary has multi volt ,33v 0v,13.5v 0v,2.7v 0v 2.7v,9v 0v 9v.The power consumption is 28watts only.How you work out 28watts with all secondary windings to find amps so I can calculate for total VA,and wire gauge?.Some one out there...
sorry bout long lead up
retractable cords, pet/id leashes and tape measuers work the same way
they have a really long metal band coiled inside, anchored on 2 separate pieces
this coiled up band of metal gets tighter as you pull, and tries to uncoil when let go
my questions/problems are as such...
Q1:
So I'm trying to extract the electrical properties of a single phase induction motor. First off, how am I supposed to measure the phase difference between the start and run windings? I have L and R of start and run windings too!
Q2:
I have a torque vs slip curve up until 130% of rated load...
The definitions of the winding number, that I have found, do not consider the case in which the point lies over the curve. Is there the winding number undefined ? I'm interested in this issue because I'm writing an algorihm for polygon offsetting that as first step creates a row offset polygon (...
1. Homework Statement
Find V2. Everything else is available in the picture
Homework Equations
r1=r1+a^2*r2
x1=x1+a^2*r2
z2=a^2*r2
I1=vp/z2+r1+x1
The Attempt at a Solution
So I have used the first three formulas but it's the last one I am getting stuck on.
Since my x1 is an imaginary number...
I am attempting to reverse engineer a small 1960's vintage power transformer that is employed in a vintage audio amplifier. It contains no marking to indicate operating voltage or current ratings, however I do have several sample transformers as well an an operational example of the amplifier...
First, take the case of a winding with a regular capacitor connected to both terminals of the winding. When a moving magnetic field induces a voltage therein, the cap becomes charged and a current flows in the conductor while cap is charging, producing a magnetic field.
Next, take the case of a...
Dear PF members.
I have trouble understanding how zero sequence currents circulate in a delta winding. For example zero sequence currents such as 3rd harmonics, they will circulate in the delta winding and get trapped, why?
Why can they not go further?
I have recently started to study...
OK, so imagine you have a wire coiling over itself, in a near concentric spiral. When you get to the outer most edge, such as 10 or 100 wrappings depending on thickness, you then bend the wire so it's one diameter of the wire over and then start spiraling inward, till you get to the smallest...
Homework Statement
Homework Equations
R2=R1(1+alpha(t2-t1))
The Attempt at a Solution
R1=250/5=50ohms
R2=250/3.91=63.94ohms
R2=R1(1+alpha15degrees(t2-t1))
63.94=50(1+1/254.5(t2-15))
t2=
Now I found this online but the answers provided still don't match, 84.25 being the closest.
When...
Where I can find the coils winding diagram for a 3PH DC PMSM (Permanent Magnet Synchronous Motor) that has a stator with 72 slots for the windings?
The same PMSM has a rotor with 8 PM's mounted on the rotor and a resolver's metal plate.
My Father's friend repairs electric motors and, occasionally, he comes to me with questions that require more of an "engineering knowledge." He asked me this past Sunday if I could explain to him what are Chord and Chording Factor, and, as has happened to me before, I felt I had a pretty good...
Homework Statement
Hi,
I know that this probably is easy to calculate, but I have the ability to thing the opposite about problems, therefore I'm stuck with this one. The question is
Determine the number of times the magnetic field has wound around the Sun by a heliocentric distance of 70...
I am wrapping a transducer coil and had a question with the winding direction. Let's say that I am wrapping the wire around a bolt in a clockwise direction. After I reach the halfway point of the wire, if I then reversed the direction I am winding to counter-clockwise, what would it do? I am...
What is the effect of motor winding end turns on torque for small DC brushless motors.?
Many state that end turns have no effect on torque and that the only influence is from the winding portion in the stator slots.
My belief is that because the end turns on small brushless motors are still...
Homework Statement
I have a set of data that I need to use to calculate the stator to winding turns ratio. A hint was given:
"The rotor current measured is the rotor winding current. However, the rotor current we use for our calculations is the current referred to the stator side of the...
I need to make an electromagnet with maximum 20mm dia including winding.
I have an iron core of 10mm dia and 20mm length.
I can't decide
- which wire to choose,
- what no. of turns should i provide
- how much current should i pass through the wire.
- what should be the voltage.
Any help and...
while studying the purpose of tertiary winding in the this 3-winding transformer , I'hv gone through a statement that " the zero sequence component caused by line-to-neutral load on secondary side cannot be balanced by primary currents as the zero sequence currents cannot flow in isolated...
Hi,
So if you wind a bifilar core in parallel and: connect it up in series, then it will have twice the N of if you connected them in parallel, i.e. The inductance is proportional to (2*N)^2 rather than just N^2, as connecting them up in parallel just increases the cross sectional area of the...
So I've been told that the direction that you wind a coil will determine the polarity of the induced voltage across the coil. I drew out two coils with clockwise and counterclockwise winding direction and with using the right hand rule and saying that the positive polarity of the induced...
Hi guys I am looking for help with some formulas, its for hnc mech eng, the question is as follows a winding drum with moment of inertia 24 kg m2 and a winding radius of 0.6m is used to accelerate a loaded hoist with mass of 850kg at a rate of 0.8ms by means of a cable, frictional resistance can...
Hello all!
I am carrying out the theoretical (that is, by calculation means) unsymmetrical fault calculations for three winding transformer.
It is to my understanding that for the zero sequence impedance for a three winding transformer depends on the winding connections of the generator and...
Dear Sir,
The rating of a single phase transformer is 230V / 230V (1:1), 5A, 50 hz, 1200W.
When this transformer is operated at 230V, 5A, and 50 hz the transformer winding saturated temperature may be some value. Now when the same transformer is operated at 230V, 5A and 40 hz (reduced...
i know that in lap winding the number of parallel path are equal to the number of poles, and in wave winding its always two.
but where is that parallel path..? , i just don't get it.
i'm new to this subject.
thank you.
Homework Statement
Hi
Can someone please tell me how to set equations for the following problem:
A cord of length L is wound on a hollow bobbin (inner radius r and outer radius R). Cord on cord friction (static) coefficient (Ctc) and cord on bobbin (Ctb) friction (static) coefficient...