Questions tagged [alternator]
Electrical generators that produce alternate current.
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1answer
76 views
One Way Current Restrictor
Will the below circuit act as a one-way current restrictor to allow 100A to flow out of the battery, but limit charging current to 10A into the battery from the alternator?
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3answers
94 views
Alternator current when charging flat battery
I've found some voltage-current-rpm graphs for car alternators and did not quite understand one thing.
Basically, my alternator is rated at 75A (small car), which it should output above 2000 RPM or so....
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2answers
48 views
Impedance of individual component in complex AC circuit
In a AC circuit with just a capacitor or inductor, reactance is the impedance of the component, and in a non-complex RLC circuit you can just find the total impedance with vector addition (Ztot = sqrt(...
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2answers
29 views
Charge AGM battery from car alternator
What is the most efficient way of charging an AGM battery using a car alternator? I have a 12V plug connected to alligator clips which can be used in the 12V sockets inside the vehicle. Is this the ...
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1answer
80 views
4 channel digital scope
I wish to view 3 phase waveforms from an alternator (DUT) through isolation transformers via a digital oscilloscope. A 4 channel oscilloscope is obviously ideal for this as I can view the waveforms as ...
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1answer
70 views
Can car alternator back-emf damage electronics?
I know on startup a motor or generator produces back-emf and current ( correct me if I'm wrong, been a while since I've worked with electric machinery ). Thus, it'd be reasonable to expect that when ...
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1answer
106 views
How many horsepower does an alternator take from an engine at different speeds? [closed]
I want to know how much horsepower the engine deliver to the alternator at idle rpm,normal rpm and maximum rpm
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0answers
72 views
How do I bring back to life a very un-excited 3phase 10kVa alternator
We are restoring a water mill and have recently got our 2 wheels turning once more. One of them is connected to an existing 3phase 10KVa alternator which although a little old seems to be in good ...
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1answer
281 views
AVR regulation brushless vs. brush alternator
I am currently looking for an AVR for a brush alternator. Today, brushless alternators seem to be more common and so is the supply for AVRs to work for brushless alternators.
My assumption is that ...
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2answers
199 views
How to monitor an Alternator exciter wire with MCU?
I have a internally regulated vehicle alternator which uses a conventional battery light wired in-between the exciter terminal and positive.
Obviously when the alternator isn't turning the exciter ...
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1answer
62 views
What are these SOT23 components in this RPM gauge circuit?
I'm trying to work out the input portion of the input circuit on a digital RPM gauge. It accepts a W input from a standard automotive alternator.
I can't identify the JCL446 which only uses two of ...
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2answers
56 views
wind turbine voltage multiplier
I am building a wind generator with a car alternator without a gearbox.
I know that the alternator is designed to spin at 5-10k RPM and the blades runs at 60-120 RPM so the alternator generates less ...
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1answer
231 views
Why use a star or delta connection instead of having a second output
I am winding my own small three phase ac alternator and have learned about star and delta connections. Should I use 2 three phase rectifiers to turn the current to DC or only one with a star ...
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4answers
72 views
What stabilizes the alternators/generators?
I've completed my intern in hydroelectric power plants. I've seen large generators working to maintain voltage in 50Hz. They were turning at 187,5 rpm with 32 poles. But I wondered what stabilizes ...
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1answer
38 views
Drawing power from only one phase of a 3 phase alternator
Note: I am busy learning about 3 phase alternators. A lot of my understanding is theory so I'm running through scenario's for better understanding.
Scenario:
Lets say we have a 2KW-220V-50Hz 3 phase ...
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3answers
638 views
Can a generator give me shock?
Can an isolated AC system like a generator which is not system grounded will be able to give me a shock if I touch it one wire? I guess it should not, because then there would not be a path back to ...
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2answers
160 views
Smoothing capacitor for scooter regulator - High constant current drawn
I've researched the forum before posting, but it seems my question is a bit specific and not answered before. Please excuse me if I'm wrong.
So what we have here is a chinese scooter alternator, ...
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1answer
70 views
Why does the electrical power of a generator that is close to the short-circuit fault location decrease?
I was reading about shunt faults in power systems in the book Fundamentals of Power System Protection by Y.G. Paithankar and S.R. Bhide and the following sentence confused me:
"Further, in an ...
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2answers
52 views
when i connect two alternator together how much is
I saw in large power plant a lot of huge generators connected together so i wondering
when i connect two generators together in parallel ( both at 120 volts ) at same phase , frequency and speed, how ...
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0answers
185 views
Lowering the voltage of a motorcycle regulator
I've recently replaced the voltage regulator on my TW125 and it seems the voltage is a bit high for the AGM 12V battery that's inside.
At the moment, I have north of 15V unloaded with just the full ...
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2answers
583 views
Varistor transient overvoltage protection of generator
Using a varistor is a common practice in alternator excitation system. It is used with rotating rectifier diode. Is it used for transient overvoltage protection?
Is it protecting diode or rotor ...
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1answer
80 views
Why symmetrical component analysis is necessary for fault calculation?
If a 3 phase fault occurs the direct axis sub-transient reactance is sufficient to calculate the fault current. But in case of an unbalanced fault it is not.
Taking the example of Line to Ground ...
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1answer
538 views
380/220 vs 220/380
we just purchased a generator, and we hired a team to hook it up to our office, they recently encountered a problem when they tried to run the generator, it would generate 380V, instead of the 220V ...
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1answer
36 views
Center of star configuration
is there any reason to connect the center of winding to the ground of 3 phase rectifier? Or shouldn't I do that?
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1answer
438 views
Why does the output voltage of an alternator increases when it is connected to Capacitive load?
Why does an alternator output voltage gets higher when it is connected to capacitive load than it was with a inductive or resistive load?
I understand that when a capacitive load is connected it ...
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0answers
266 views
How to make a permanent magnet?
Just recently I got a broken car alternator, which I would like to transform to permanent magnet generator. For that purpose, I would have to make permanent magnet of finger poles on the rotor.
The ...
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1answer
78 views
Why the shape of rotor-poles of salient pole synchronous machines are designed as sinusoidal in shape?
I knew that this is done to eliminate harmonics. But I couldn't get its reason. So I am confused whether my conclusion was right or wrong.
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2answers
99 views
Power dissipated is maximum or minimum when step up transformer is used
The large scale transmission and distribution of electrical energy over long distances is done with the use of transformers. The voltage output of the generator is stepped-up (so that current is ...
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1answer
96 views
Pass power to components on a high speed spinning motor
I have a small Emax RS2205 2600kv 16v DC Motor that is turning a PCB with IC chips that needs to be powered.
I want to send 2 power cable (VCC and GND) from to stationary battery to the rotating PCB.
...
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4answers
1k views
3 Phase alternator to charge batteries
I'm trying to understand how a car alternator efficiently charges the battery.
I don't understand why a power-factor controller isn't needed to effectively use the alternator. Current would only ...
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0answers
364 views
Why is the chording angle 30 degrees, in a practical alternator?
So far what i have understood...
Chording angle in Synchronous Generator/ Alternator is introduced to tackle the problem of harmonics that couldn't be taken care of during the design either in -
...
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2answers
195 views
Inductive kickback when applying PWM to the output of an alternator
simulate this circuit – Schematic created using CircuitLab
I've got a fairly odd LED setup whereby a vehicle's alternator is being used to generate the power (rectified to DC) required to run ...
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2answers
238 views
How does a car alternator work?
I am a beginner and my question is the following:
The alternator has an output voltage 13.7V. I know that each load is not a linear resistor but each load represents a certain resistance to the ...
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1answer
1k views
How do I calculate the output current of an alternator [duplicate]
Do alternators obey Ohm’s law? The alternator output voltage is proportional to the rotor excitation current. When reducing rotor excitation, the output voltage drops and the load resistance stays ...
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2answers
241 views
How does ohm's law works in practice [closed]
1 Does this means for example that alternator even with low rotor magnetic field strength and low output voltage on stator will obey ohm law and give current proportional to resistance and voltage . ...
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0answers
126 views
alternator reactive power
I'm tying to calculate the change in reactive power of an alternator with the change in its real power input.
P=EV/Xs sin(d) is the real power output of the generator.
Q=EV/Xs cos(d) - V^2/Xs is the ...
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1answer
72 views
Speed voltage variation in alternators
What happens to the terminal voltage of synchronous generator if we change the speed ?
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1answer
78 views
Why am I given two reactances for a synchronous generator?
I'm solving problems on the alternator and some of them give a reactance Xq in addition to the usual synchronous reactance Xd. Does anyone know what this Xq is?
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45 views
Disconnecting the load from a synchronous generator
How is the terminal voltage of a synchronous generator affected when we disconnect the load ?
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1answer
565 views
Secondary car battery voltage
I have an accessory battery for powering devices when the vehicle is off. The Secondary battery is connected through a battery isolator. Each battery is separately connected to chassis ground. When ...
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4answers
984 views
How do I connect light bulbs to an alternator on a bike?
Some friends and I are working on a school project and need a bit of help. The basic premise is that we’re using a bicycle (which is kept stationary) to spin an alternator and power some lightbulbs. ...
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928 views
how to increase the amperage of an alternator?
many application demande a high amperage like induction heater, elelectrolysis etc....
So if an alternator generate 100 ampers and a voltage of 14 or 15 volt .
how to increase the amperage to 1000 ...
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1answer
92 views
Limiting 14V current to 50A
Given multiple possible powerful charge sources without adequate over-current protection, and a very large (say 500 AH) depleted battery bank, using a very low resistance / high acceptance rate ...
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1answer
582 views
Voltage regulation in alternator
A single phase, 2000 V alternator has armature resistance and
reactance of 0.8 Ω and 4 Ω respectively. The voltage regulation of
alternator at 100 A load at 0.8 leading power factor is _______?
...
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1answer
44 views
Switching setup to reverse B2B charging direction
Say I have 2 of 400AH 12V DC battery banks, "A" and "B", and bankA is mobile, opportunistically charged by a HO alternator, the bankB is stationary, charged by a genset and topped up by a large solar ...
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3answers
2k views
3-phase regulated “ideal” rectifier
In motorcycles broken stock voltage regulator is a very common issue.
Stock solution is SCR based and commonly burns due to overheat/ SCR failure.
DIY regulators usually have the following design (...
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3answers
1k views
Can a 50 Hz, 220 VAC transformer work on 40 Hz, 180VAC?
I am designing an AC to DC converter. My power source is a single phase synchronous alternator that has a voltage range of 170~260 VAC and a frequency of 40~60 Hz. Can i use a transformer designed on ...
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0answers
87 views
Paralel PB Battery in a car as backup power for Arduino
Quick question. I want to run Arduino in my car and have a battery backup for it.
So when car is started - it should run on alternator power, and when stopped run on the backup battery.
I was looking ...
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1answer
298 views
240V AC to ~380V DC converter at 3500 continuous watts
I have a single phase 5KW generator connected to a diesel engine capable of producing approx 3500 Watts of power
I need to convert the 240V AC to DC in order to send it to my solar charge controller ...
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0answers
49 views
Does an HEV Genset need a controller?
I am part of a team at school that designs and builds a hybrid electric vehicle. We have chosen to use a series hybrid configuration, so we will be using a motor as a generator to charge lithium ...
