Alternator AC ripple test? (Suits you)

A multimeter can read AC voltage and can be used to test for ripple. The alternator should be replaced if AC voltage of more than 50mV is detected (in some cars as much as 100mV is acceptable). If there is more than 0.1 volt (50-100mV, depending on the vehicle) of AC ripple, then the alternator is most likely bad.

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  • A multimeter can read AC voltage and can be used to test for ripple. The alternator should be replaced if AC voltage of more than 50mV is detected (in some cars as much as 100mV is acceptable). If there is more than 0.1 volt (50-100mV, depending on the vehicle) of AC ripple, then the alternator is most likely bad.

What does excessive ripple in alternator test?

Excessive ripple voltage can cause communication issues with networks and communication DTCs in multiple modules. Before computers and networks in vehicles, an alternator that was producing AC voltage or ripple through the electrical system would cause flickering lights and maybe an ignition problem.

What does alternator ripple mean?

Rabble-Rousing Ripple Diodes rectify the stator’s AC current into DC. Although this happens, a small AC voltage still appears at the alternator’s output terminal. When properly displayed on a scope screen, this AC voltage has a rippled appearance; consequently, it’s called alternator ripple.

What is acceptable alternator ripple?

A multimeter can read AC voltage and can be used to test for ripple. The alternator should be replaced if AC voltage of more than 50mV is detected (in some cars as much as 100mV is acceptable). If there is more than 0.1 volt (50-100mV, depending on the vehicle) of AC ripple, then the alternator is most likely bad.

What causes excessive ripple in an alternator?

There are electronic components inside the alternator called diodes that are responsible for keeping the ripple as small as possible. If one or more diode fails the ripple becomes excessive.

Why is ripple voltage bad?

Ripple is wasted power, and has many undesirable effects in a DC circuit: it heats components, causes noise and distortion, and may cause digital circuits to operate improperly. Ripple may be reduced by an electronic filter, and eliminated by a voltage regulator.

What is battery ripple test?

Ripple most commonly refers to an undesirable amount of AC voltage fluctuation on the DC power supply. During vehicle charging and power conversion, EV batteries constantly have to face such troublesome power ripples. EV batteries thus require ripple current testing to ensure quality.

How do I test my alternator with a multimeter?

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  1. Get a multimeter.
  2. Set your multimeter to DCV (DC Volts) above 15.
  3. Make sure your alternator’s positive and negative terminals are clean.
  4. Put the multimeter’s black cable to the negative terminal and the red cable to the positive terminal.
  5. Look for an ideal alternator reading of around 12.6.

What causes alternator diodes to fail?

Because of the substantial load handled by the alternator, the rectifier diodes fail because of overheating, overloading or because of poor connection between the alternator output and the battery positive terminal. Leaky or shorted alternator diodes can cause rapid changes in the output voltage of the charging system.

Alternator Ripple Testing: The Ghost in the Machine

An alternator that was creating alternating current voltage or ripple across the electrical system would produce flickering lights and, in certain cases, an ignition problem prior to the introduction of computers and networks in automobiles. Extremely high levels of ripple voltage can create communication problems with networks and communication DTCs in various modules these days. An alternator that was creating alternating current (AC) voltage or ripple across the electrical system would produce flickering lights and, in certain cases, an ignition problem prior to the introduction of computers and networks in automobiles.

More information is available by clicking here.

The alternator, on the other hand, transforms mechanical energy into electrical energy by the use of electromagnetic induction, which produces alternating current, also known as AC current.

The rectifier consists of three to eight diodes, which enable the negative current of an alternating current sine wave to travel to ground through them.

  1. When a diode fails, the quantity of direct current (DC) reduces, and in some situations, the alternating current (AC) makes its way into the power supply of the car.
  2. The waveform of a typical diode failure will be asymmetric, rather than steady, as seen in the diagram.
  3. If an alternating current voltage of greater than 50mV is recorded, the alternator should be changed (in some cars as much as 100mV is acceptable).
  4. In many cases, low frequency, visible, and rhythmic voltage ripple is caused by worn brushes in voltage regulators, which are responsible for the ripple.
  5. Any time there is an increase in AC ripple voltage (50-100mV, depending on the vehicle), the alternator is most likely malfunctioning and should be replaced.
  6. In order to check the battery voltage while the engine is not running, make sure that the meter is set to read voltage while in the alternating current mode.
  7. Depending on the accessories that have been placed in the vehicle, the typical current draw should be less than 40 milliamps.
  8. A larger value might be obtained if there is a parasitic loss present in the charging mechanism.
  9. The new alternator passed the ripple test with a result of 55mV, which was considered satisfactory.
  10. All of the earlier alternator testing indicated that the alternator was either loaded or not loaded at roughly 12V.

As a result, the car was operating at a speed that was dangerously near to depleting the battery under load. Because of the increased voltage output following the alternator repair, as well as the nice ripple, it was undoubtedly another instance of a ghost in a machine.

Modern Ripple Diagnostics

In earlier automobiles, a faulty diode would cause a warning light to illuminate on the dashboard. However, with today’s sophisticated automobiles, which are equipped with sensors, modules, and networks, stray alternating current voltage can create a broad range of difficulties. The electrical system, in contrast to your scope or multi-meter, is unable of distinguishing between alternating current and direct current. If the ripple voltage reaches specified thresholds, it can cause interference with a three- or five-volt CAN bus line, depending on the application.

  • When you look at an alternating current voltage sine wave, you will see that it alternates between positive and negative volts.
  • When the signal is decoded by the module, it is revealed to be gibberish.
  • Stray alternating current (AC) voltage can also interfere with engine position sensors and even actuators that are pulse-width modulated, according to the manufacturer.
  • It is not until the engine is operating at a speed greater than 1,500 rpm that the alternator begins to create alternating current voltage.

Alternator Ripple Testing: The Ghost in the Machine

Overly high ripple voltage can cause communication problems with networks and communication DTCs in numerous modules when used in conjunction with other modules. Here’s all you need to know about the situation. Brendan Baker is a technical editor for Babcox Media Inc., where he has worked since 2007. An alternator that was creating alternating current voltage or ripple across the electrical system would produce flickering lights and, in certain cases, an ignition problem prior to the introduction of computers and networks in automobiles.

  1. More information is available by clicking here.
  2. However, the alternator converts mechanical energy into alternating current by using electromagnetic induction, which generates alternating current (or AC current).
  3. The rectifier has between three and eight diodes, which allow the negative current of an alternating current sine wave to flow through to ground through a series of diodes.
  4. When a diode fails, the quantity of direct current (DC) reduces, and in some situations, the alternating current (AC) makes its way into the power supply of the car.
  5. The waveform of a typical diode failure will be asymmetric, rather than steady, as seen in the diagram.
  6. If an alternating current voltage of greater than 50mV is recorded, the alternator should be changed (in some cars as much as 100mV is acceptable).
  7. In many cases, low frequency, visible, and rhythmic voltage ripple is caused by worn brushes in voltage regulators, which are responsible for the ripple.

Any time there is an increase in AC ripple voltage (50-100mV, depending on the vehicle), the alternator is most likely malfunctioning and should be replaced.

In order to check the battery voltage while the engine is not running, make sure that the meter is set to read voltage while in the alternating current mode.

Depending on the accessories that have been placed in the vehicle, the typical current draw should be less than 40 milliamps.

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A larger value might be obtained if there is a parasitic loss present in the charging mechanism.

The new alternator passed the ripple test with a result of 55mV, which was considered satisfactory.

All of the earlier alternator testing indicated that the alternator was either loaded or not loaded at roughly 12V.

As a result, the car was operating too near to the battery’s capacity to deplete it while under load. Because of the increased voltage output following the alternator repair, as well as the nice ripple, it was undoubtedly another instance of a ghost in a machine.

Modern Ripple Diagnostics

In previous automobiles, a defective diode would trigger a warning light to illuminate on the dashboard; however, in today’s contemporary vehicles, which are equipped with sensors, modules, and networks, stray alternating current voltage can create a broad range of difficulties. The electrical system, in contrast to your scope or multimeter, is incapable of distinguishing between alternating current and direct current. If the ripple voltage reaches specified thresholds, it can cause interference with a three- or five-volt CAN bus line, depending on the application.

  • When you look at an alternating current voltage sine wave, you will see that it alternates between positive and negative volts.
  • When the signal is decoded by the module, it is revealed to be gibberish.
  • Stray alternating current (AC) voltage can also interfere with engine position sensors and even actuators that are pulse-width modulated, according to the manufacturer.
  • It is not until the engine is operating at a speed greater than 1,500 rpm that the alternator begins to create alternating current voltage.

Quick Tip: Alternator Ripple Test

Are you having difficulty identifying electrical problems in your vehicle? In this Diagnostic Quick Tip, National Field Trainer Jason Gabrenas demonstrates how to make things simple by performing the Alternator Ripple Test on the alternator.

VIDEO TRANSCRIPTION

This thing called a Top Level Menu is found in the Guided Component Tests, as well as in all of our lab scope products, and it is one of the most powerful tools available. All kinds of tests, suggestions, and perhaps even power user tests that are a bit more complex than the ones that we already have within the tool are available to us through this feature. An alternator ripple test will be discussed in detail today. If you believe that you have an electrical problem in your automobile, this should be one of the first things you should perform.

  • So I’m going to walk you through the process of getting in there.
  • Go to Top Level Menus and How To, then this test is under test tips, and it’s the very first thing you see when you get to the top of the page.
  • We’re going to load it up, then we’ll see how to connect it in the second section, where it says to connect the yellow wire to the alternator output and the black wire to the battery positive.
  • So I’m going to scroll down a little bit more and see if it offers us any hints of what a good pattern looks like in terms of structure.
  • Consequently, I’m going to hit view meter here, which should bring up my meter, and then I’m going to go over to the car and start it to check what the alternator looks like on this particular kind of vehicle.
  • With the exception of a little amount of noise, we have a generally nice pattern here to work with.
  • As you can see in this awful pattern, there are a few bumps and then something drops out, and then there are a few bumps and then something drops out again.

Consequently, this is an excellent spot to begin your diagnostics, particularly if you suspect that your car is experiencing an electrical malfunction. Because if you have a poor alternator, you may find yourself on the incorrect way, and you would not want to waste any time getting there.

Alternator Ripple Effect

There’s an ancient adage that a picture is worth a thousand words, and this is certainly true. An oscilloscope can provide a valuable representation of the problem you’re attempting to solve, and this covers possible alternator problems as well. In the 1970s, I witnessed the first time an oscilloscope was utilized for alternator diagnosis. Since then, I’ve been putting it into practice with both analog and digital scopes. I’ll try to clear up any misunderstandings you may have regarding this strategy in this essay.

  • However, this was not always the case.
  • Consider the following scenario: a car with one or more electrical symptoms arrives at your store.
  • If your scope displays a normal pattern while the alternator is delivering its rated output in amps, this indicates that the diagnostic is complete.
  • Instead, it’s more probable that the electrical and/or driveability symptoms are caused by anything other than the alternator itself.
  • That is why I oppose the removal of alternators and advise the use of these well-established processes.
  • A reliable replacement, on the other hand, is not inexpensive.
  • Because of this, replacing an alternator should be the final option examined rather than the first.

First and foremost, contemporary alternators share a number of significant characteristics.

When a voltage regulator detects an increase in electrical load, it should switch the field circuit on for a longer period of time, causing the alternator to generate more amps.

The voltage regulator is normally found within the alternator, hidden from view.

When designing a computer, such as the PCM, it is common for designers to incorporate the voltage regulator.

This is the simplest diagnostic to make since the alternator is completely dead; it will not produce any amps or volts under any circumstances.

A properly functioning rotor transfers energy to a stationary collection of windings known as a stator.

A stator is made up of three separate windings, which are referred to as phases.

Typically, stator failure indicates that one of the three windings has opened up or shorted internally or to ground, depending on the situation.

But, wait a minute, don’t we require direct current?

A diode is a one-way electrical check valve that serves a functional purpose.

The alternator’s output terminal, which is typically designated B, B+, or BAT, is then used to discharge this direct current into the surrounding environment.

When a number of diodes come together, they create an assembly known as a rectifier, which transforms alternating current (AC) into direct current (DC).

In most cases, when a rectifier fails, it is because one or two of the diodes within it have opened up.

The short then generates such high levels of heat that the diode immediately burns open.

As a result, partial alternator failures, which result in undercharging, are rather common.

The Ripple of Rabble-Rousing Here are some more blatant oversimplifications for your consideration.

Despite the fact that this occurs, a tiny alternating current voltage is still visible at the alternator’s output terminal.

At the very least, a healthy alternator can perform two functions.

On a scope, it provides a clean, constant ripple pattern, which is the second benefit.

Remember that the degree of undercharging varies from one car to the next, so be cautious.

Another problem with an alternator is that it cannot produce a clean, constant ripple pattern when its rectifier or stator malfunctions.

A valid rectifier or stator failure will always result in clear, recurring changes in the pattern of the underlying signal.

When it comes to analyzing ripple patterns, the repeating fault concept is critical.

It’s possible that the alternator in question is the ancient Delco-Remy 10DN, which was installed in a 1972 Chevrolet Malibu.

It really doesn’t matter what you’re looking for when scoping ripple patterns.

The failure of a diode or a stator has an effect on one or more of the phases.

So the problem constantly re-appear on the ripple pattern every time the scope displays that phase, indicating that the fault is still present.

Overall, an undercharge state in conjunction with a poor ripple pattern indicates that it is time to replace the alternator.

Techs frequently inquire about the amplitude (height) of a good ripple pattern and if it should be larger or smaller.

This was taught to me by an engineer by the name of Juan Grube a number of years ago.

For almost 40 years, the firm has been manufacturing professional alternator/starter test devices.

He claims that he has never come across OEM specs for this AC value before.

Second, his vast research found a range of values for alternators that were previously known to be good.

Third, a diode or stator failure causes an increase in the alternating current voltage at the output terminal.

However, comparing your AC voltage measurement to that of a known-good alternator—while running at the same rpm and with the same electrical load—is a more accurate technique.

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According to Grube, the stator voltage of a healthy alternator measures one-half the voltage at the output terminals.

Typically, Grube’s advice to a scope user is to first fill the charging system before looking for a clean, consistent ripple pattern.

This has proven to be quite useful guidance.

A scope, an electrical load, and, if applicable, a throttle-holding tool are all required for the testing.

The most likely scenario is that your scope is a digital model.

If this is the case, then by all means continue to use the existing test setup.

Set up the scope accordingly and start with a vertical scale of 1.00V AC.

Then patiently adjust the horizontal time scale until the image resembles the ripple patterns shown in this article.

If your scope allows you to save the voltage and time settings for future tests, save them and create your own personal alternator test preset.

The filter simply screens out DC voltage so the scope displays only whatever AC voltage is present.

The test lead, Part No.

Forewarned is forearmed: Alternator ripple patterns may look unusually “noisy” and ragged.

For another, try connecting the positive scope lead to the positive battery terminal.

Critics of this approach insist that the output terminal is the only valid test point for alternator ripple patterns.

I’ve always observed that a true diode or stator failure looked as legitimate at the battery as it did at the alternator output terminal.

Conversely, neglecting the load is a common cause of misdiagnosis.

Obviously, you can’t control alternator design.

One straightforward technique is to attach the scope, start the engine and use as many accessories as reasonably possible, then observe the ripple pattern.

I typically switch on the high beams in the headlights, the front and rear defrosters, the blower fan at its maximum setting, the heated seats, and the music system.

Using a variety of accessories switched on, I measured 60A at 14.40V when the engine was running hot.

This type of battery tester is equipped with a durable, adjustable carbon-pile resistor (or equivalent) that puts actual load on the battery.

The load tester should be connected to the battery, and the inductive clamp should be placed around the alternator output wire before starting the engine.

Then, using the scope, look for a pattern of ripples.

Either one of these conditions exists or the other does not!

The engine speed is maintained at around 2000 rpm by some technicians using a throttle-holding tool during the ripple test.

It vertically extends the pattern and may make it easier to evaluate the ripple as a result.

The unit should, without a doubt, be capable of producing the volume for which it is rated.

In that situation, everything should be excellent—period!

Perhaps a warning message appeared on the instrument panel, or perhaps the charge indicator light illuminated.

However, if the alternator survived this rigorous examination, I strongly assume that the source of the vehicle’s problem lies elsewhere.

For as long as I can recall, firms that manufacture original equipment alternators have conducted this output and ripple test.

In addition, skilled auto-electric rebuilding firms are well-versed in the process.

However, when properly executed, it takes only a few seconds and provides peace of mind.

I used a very simple digital scope since even the most basic of tools may be really helpful in certain situations.

I was able to catch Patterns 4 and 5 after installing a Honda Accord alternator with an open positive diode.

Those settings occurred to be.50V on the vertical scale in this particular instance.

In the upper left corner of page 24, you can see pattern 1 compared to patterns 2 and 3.

Comparing the open positive diode in pattern 4 on that page to the typical diode in pattern 1 can help you understand how they differ.

There is a significant and immediately noticeable difference between a healthy pattern and a poor one—especially when under stress.

There was a 60A Nippondenso from a Civic that was operating at the equivalent of rapid idle in this experiment.

The vertical scale of the scope remained the same, but the horizontal scale was adjusted to one millisecond per division (1 ms/) to accommodate the change.

This alternator was altered by a friend of mine so that I could manufacture and remove faults using strong jumper wires that protruded from the device.

Pattern 7 depicts a positive diode that is open.

Neat?

Take, for example, the measurements taken at rapid idle with no load on this Civic unit’s generator.

Alternatively, consider the performance of the alternator after I installed the open diode: 60A at 13.00V!

The ripple pattern, on the other hand, indicated differently.

However, despite its failing condition, the alternator still delivered its rated amps output.

Before I conclude, I want you to keep in mind two fundamental yet critical points: First and foremost, don’t forget to perform a comprehensive battery test.

Second, an excessive voltage drop between the output terminal and the battery may have an impact on the findings.

Don’t be afraid to take a printout of your test findings.

Provide the consumer with another.

In conclusion, a ripple pattern may be used to present a relevant picture of the health of an alternator.

Every week, do the test on two alternators that have been proven to be reliable. I’m willing to wager that you’ll come to like ripple pattern checks as much as I do in the near future. Wishing you the best of success in your endeavors and remember to smile.

Alternator Ripple Voltage Testing

An alternator that was creating alternating current voltage or ripple across the electrical system would produce flickering lights and, in certain cases, an ignition problem prior to the introduction of computers and networks in automobiles. Extremely high levels of ripple voltage can create communication problems with networks and communication DTCs in various modules these days. An alternator that was creating alternating current voltage or ripple across the electrical system would produce flickering lights and, in certain cases, an ignition problem prior to the introduction of computers and networks in automobiles.

  • More information is available by clicking here.
  • The alternator, on the other hand, transforms mechanical energy into electrical energy by the use of electromagnetic induction, which produces alternating current, also known as AC current.
  • The rectifier consists of three to eight diodes, which enable the negative current of an alternating current sine wave to travel to ground through them.
  • When a diode fails, the quantity of direct current (DC) reduces, and in some situations, the alternating current (AC) makes its way into the power supply of the car.
  • The waveform of a typical diode failure will be asymmetric, rather than steady, as seen in the diagram.
  • If an alternating current voltage of greater than 50mV is recorded, the alternator should be changed (in some cars as much as 100mV is acceptable).
  • In many cases, low frequency, visible, and rhythmic voltage ripple is caused by worn brushes in voltage regulators, which are responsible for the ripple.

Any time there is an increase in AC ripple voltage (50-100mV, depending on the vehicle), the alternator is most likely malfunctioning and should be replaced.

In order to check the battery voltage while the engine is not running, make sure that the meter is set to read voltage while in the alternating current mode.

Depending on the accessories that have been placed in the vehicle, the typical current draw should be less than 40 milliamps.

A larger value might be obtained if there is a parasitic loss present in the charging mechanism.

The new alternator passed the ripple test with a result of 55mV, which was considered satisfactory.

All of the earlier alternator testing indicated that the alternator was either loaded or not loaded at roughly 12V.

Because of the increased voltage output following the alternator repair, as well as the nice ripple, it was undoubtedly another instance of a ghost in a machine.

However, with today’s sophisticated automobiles, which are equipped with sensors, modules, and networks, stray alternating current voltage can create a broad range of difficulties.

If the ripple voltage reaches specified thresholds, it can cause interference with a three- or five-volt CAN bus line, depending on the application.

When you look at an alternating current voltage sine wave, you will see that it alternates between positive and negative volts.

When the signal is decoded by the module, it is revealed to be gibberish.

Stray alternating current (AC) voltage can also interfere with engine position sensors and even actuators that are pulse-width modulated, according to the manufacturer.

It is not until the engine is operating at a speed greater than 1,500 rpm that the alternator begins to create alternating current voltage.

Alternator – an overview

An alternator that was creating alternating current voltage or ripple across the electrical system would produce flickering lights and, in certain cases, an ignition problem prior to the introduction of computers and networks in automobiles. Extremely high levels of ripple voltage might create communication problems with networks and communication DTCs in numerous modules nowadays. An alternator that was creating alternating current voltage or ripple across the electrical system would produce flickering lights and, in certain cases, an ignition problem prior to the introduction of computers and networks in automobiles.

  • Read More by visiting this link: It is necessary for computer modules and sensors to be included into the overall system, and the charging system must provide direct current to a somewhat steady DC voltage level.
  • A rectifier is used to convert alternating current (AC) to direct current (DC) within the alternator.
  • Consequently, only direct current (DC) and a very little quantity of alternating current (AC) remain, which are normally absorbed by the battery.
  • Ripple voltage is measured on a scope using the appropriate filter or leads to examine the alternating current generated by a diode.
  • A multimeter may be used to read alternating current voltage and to check for ripple in the power supply system.
  • The ripple test, on the other hand, can be thrown off by a dead or weak battery, so ensure sure the battery is completely charged before running it.
  • Assuming that the engine has been sufficiently warmed up and is running at roughly 1,500 rpm, the DMM should be set to read AC volts and the battery should be measured when the headlights and blower are turned on to place some strain on the electrical system.
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If you are using an AC meter, be sure that the DC voltage is blocked by the device.

If the DC is blocked, it should not indicate any voltage.

Alarm systems, for example, will take an excessive amount of electricity.

The alternator needed to be changed after a ripple test revealed that it was faulty.

It produced 13.9V without a load and 13.6V when loaded by the new alternator.

As a result, the car was operating at a speed that was dangerously near to depleting the battery’s capacity.

Diagnostics of the Modern Ripple A faulty diode would cause a warning light to illuminate on the dashboard of older automobiles.

Because the electrical system is incapable of distinguishing between alternating current and direct current, unlike your scope or multimeter, CAN bus lines with voltages of three or five volts are susceptible to being interfered with if the ripple voltage exceeds specific thresholds.

Observe the sine wave of alternating current (AC voltage), which alternates between positive and negative voltages.

As soon as the signal is decoded by the module, it is shown to be gibberish!

Stray alternating current voltage can also interfere with engine position sensors and even pulse-width modulated actuators.

The alternator does not begin to generate alternating current until the engine is operating at a speed greater than 1,500 rpm.

2.2.19Three-phase alternators

The Telecommunications Engineer’s Reference Book, published in 1993 by Clive R. Nightingale, Dip. EE, CEng, FIEE

24.2.5Alternators

1993, inTelecommunications Engineer’s Reference Book, by Clive R. Nightingale (Dip. E.E. CEng FIEE).

11.3.2.2Generator Operation

Progress in Astronautics and Rocketry, edited by R.W. Powell, 1966.

Turbine-alternator assembly:

E.Meissner’s article in the Encyclopedia of Electrochemical Power Sources was published in 2009.

Reality: AC ripple, IR drop, undercharge, deep discharge

S.S. Misra’s article in the Encyclopedia of Electrochemical Power Sources was published in 2009.

Automotive

J.R. White and A.A. Pinney, in Energy for Rural and Island Communities: Proceedings of the Third International Conference Held at Inverness, Scotland, September 1983, 1984 (Energy for Rural and Island Communities: Proceedings of the Third International Conference Held at Inverness, Scotland, September 1983, 1984).

CURRENT MODELS

inElectrical Engineer’s Reference Book (Sixteenth Edition), 2003. JSDavenport,.MJHChandlerCEng, FIEE, FICE, FIHT, inElectrical Engineer’s Reference Book (Sixteenth Edition), 2003.

Control

R. Bigret’s article in the 2001 edition of the Encyclopedia of Vibration.

Contact as a Machine Slows Down

The third edition of Applied Welding Engineering (Ramesh Singh) will be published in 2020.

Alternating current

When an alternator generates alternating current electricity, the voltage reverses polarity in a very specific manner over time. When the polarity wave trace is graphed over time, it seems to be changing fast yet in a smooth transition across the crossover line, as seen in the figure (point zero). A sine wave is the form of the curve that is created as a result of this process. This reversal occurs once per cycle, which is referred to as a wave cycle. The rate at which this alternating occurs is referred to as frequency, and it is measured in Hertz (Hz).

Because of the sine wave, the current can only penetrate to the surface of the material to magnetize it, and as a result, just the surface of the metal is magnetized by alternating current.

In a similar vein, the surface opening of a weld may be observed using alternating current magnetizing.

Read the entire chapter here: URL:

Alternator Testing

  1. Here’s an easy test to determine if the diodes in your alternator are functioning properly. My only regret is that I cannot recall where I obtained it. An alternator generates three-phase alternating current, which is delivered to a rectifier system consisting of (typically) six diodes to complete the circuit. This converts alternating current to direct current with only a minimal bit of ripple. The battery functions in a similar way as a filter, ensuring that the ripple has no effect on anything. In the event that one or more of the diodes fail, that little ripple will grow significantly larger. While the engine is running, switch on everything you can think of in the truck to save time. AC, high lights, a radio, and emergency flashers are all standard equipment. Learn how to test your alternator with a decent digital multimeter in this video. Set the meter’s AC Voltage range to the lowest possible value (Yes, AC). The black lead should be connected to the negative battery post and the red lead should be connected to the positive battery post. Start the engine at a speed of around 1500 RPM. You should not read any voltages higher than 0.09 volts alternating current. If this is the case, you will need to repair or replace the alternator. I hope this is of use to someone. The most recent edit was made on September 21, 2017. wilcam47andtan4x4 like this
  2. I’m going to give it a shot in a minute. I’ve been having issues with my alternator
  3. Please let me and the rest of the community know how things turn out for you. That test solely looks for alternating current noise or leakage. An alternator that fails the test but produces the design amperage is possible
  4. I checked two different meters to see whether this was true. One was 0.00, while the other flashed 88.2 and 0
  5. Yes, you are correct. This is by no means a complete alternator examination. According to what I understand, it merely checks for a diode failure condition. I put this out there as a tool that could be used to quickly determine whether something is a go or a no go. If you see this problem, you may be sure that your alternator is defective. Even though the results of this test are satisfactory, you may still have a defective alternator
  6. Unfortunately
  7. It appeals to me as well! This is something I’ve never seen or heard before, but it makes sense. We’ve added another tool to the thread, and I’ll give it a shot first thing in the morning. My issue is that while driving with the headlights on and everything turned on, my voltage is between 12.8 and 13.2 volts. With the headlights off and everything else on, it gets to 13.9 mph. I’ve been following this nonsense for two years. I’m getting ready to order another alternator. Currently, I have a 130 installed that I purchased from bamatoy off of this site. He doesn’t have any ideas at the moment. I checked all of my grounds using a voltmeter and techniques I learned from watching videos on youtube. The battery is three months old and performs well under load
  8. It took some time to discover this, but it may be useful for people who are familiar with the process of rebuilding an alternator. This firm provides alternator repair kits, and I came found them when browsing through the Ford Ranger Forum’s product section. I haven’t looked into whether or not Taco repair kits are available. I’ve just had my car for five weeks and am already in love with it. In any case, here is a link to a firm that offers repair kits under the “Victory Lap” moniker. When I contacted to inquire about a Ranger rebuild kit, they were exceedingly kind. The most recent edit was made on September 22, 2017.

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