Hi

Total Newbie to aac and forums in general.

Can anyone help me regarding an oscilloscope for bench testing alternators.

I am currently looking at one from Brise which simply connects to the battery and gives a single waveform.

It is rather expensive however and I was wondering if there were any other types of oscilloscopes that I could simply attach to the test bench battery and use to check the alternator output.

Sorry if this has already been covered or it is a stupid request. Never used an oscilloscope before.

Thanks in advance

Jonny

 

Don't know what's special about the Brise oscilloscope.
Can you post a link to it, or some info on it?

 

Don't know what's special about the Brise oscilloscope.
Can you post a link to it, or some info on it?

Hi
Thank you for the reply.

This is the link to the website.

www.brise.co.uk/Digital-Waveform-Monitor-CVA2.html

 

It's a specialized oscilloscope, which automatically adjusts the vertical voltage sensitivity and horizontal sweep sweep as appropriate for alternator testing, but any standard oscilloscope should be able to do the same, although it will need manual adjustment of the two ranges (which is not at all difficult).
One other difference, is that it likely is more physically rugged than a standard oscilloscope.

Do you have any cheaper oscilloscopes in mind for the task?
Is this for a business or personal use?
What is your budget?

 

It's a specialized oscilloscope, which automatically adjusts the vertical voltage sensitivity and horizontal sweep sweep as appropriate for alternator testing, but any standard oscilloscope should be able to do the same, although it will need manual adjustment of the two ranges (which is not at all difficult).
One other difference, is that it likely is more physically rugged than a standard oscilloscope.

Do you have any cheaper oscilloscopes in mind for the task?
Is this for a business or personal use?
What is your budget?

Hi

Thanks for your help.

It is for business use. We have just purchased a modern computerised alternator test bench and I would like the oscilloscope just to monitor the diodes and a.c. ripple. I was going to buy the brise unit but having never used an oscilloscope before I wondered whether any oscilloscope would do the job or whether it has to be a special one.

Looking on eBay so many different types came up I thought I'd better ask the experts and came across this website.

 

Hi

Total Newbie to aac and forums in general.

Can anyone help me regarding an oscilloscope for bench testing alternators.

I am currently looking at one from Brise which simply connects to the battery and gives a single waveform.

It is rather expensive however and I was wondering if there were any other types of oscilloscopes that I could simply attach to the test bench battery and use to check the alternator output.

Sorry if this has already been covered or it is a stupid request. Never used an oscilloscope before.

Thanks in advance

Jonny

Alternators vaguely resemble constant current sources, if you accidentally spin one up with no load the voltage can actually reach dangerous levels.

An old tube scope will be more robust, probably very cheap too.

Personally I wouldn't put a shiny new digital storage scope in an engine workshop - but you have to be careful of dew getting on the high voltage stuff in the tube variety.

 

Alternators vaguely resemble constant current sources, if you accidentally spin one up with no load the voltage can actually reach dangerous levels.

An old tube scope will be more robust, probably very cheap too.

Personally I wouldn't put a shiny new digital storage scope in an engine workshop - but you have to be careful of dew getting on the high voltage stuff in the tube variety.

Hi

I looked at some old oscilloscopes on eBay but i wouldn' have a clue how to use one.

The brise model simply attaches two leads to the battery and gives the waveform. I just wondered if there was another oscilloscope that could do the same. The more idiot proof the better haha.

 

I looked at some old oscilloscopes on eBay but i wouldn' have a clue how to use one.

There are many tutorials and Youtube videos that should get you up to speed in a hour or two.
They are not that difficult to use.

The brise model simply attaches two leads to the battery and gives the waveform. I just wondered if there was another oscilloscope that could do the same.

Not likely, unless someone else makes a specialized alternator oscilloscope.

 

There are many tutorials and Youtube videos that should get you up to speed in a hour or two.
They are not that difficult to use.
Not likely, unless someone else makes a specialized alternator oscilloscope.

I will look into using an oscilloscope online. I have used specialized motor scopes on industrial electric motor windings when i was working in rewind shops but they were pretty simple to operate.

Thanks for all the help.

 

I will look into using an oscilloscope online. I have used specialized motor scopes on industrial electric motor windings when i was working in rewind shops but they were pretty simple to operate.

Thanks for all the help.

You can get CRO based engine diagnostic consoles that might include alternator tests.

They're designed and built for that environment.

Never looked into it myself though, so you'll probably have to search for brochures.

 

You can get CRO based engine diagnostic consoles that might include alternator tests.

They're designed and built for that environment.

Never looked into it myself though, so you'll probably have to search for brochures.

Thanks I'll Google those also.

 

When I started driving (back in the 1970s), it was common practice to buy an exchange alternator to replace a failed unit. For the more adventurous you could buy a replacement diode pack, carbon brushes or voltage regulator (as required).

There were a limited number of variants based on the alternator mounting arrangement and current rating of the unit.

Fast forward to today, and many vehicle alternators rely on the ECU to provide the voltage/current regulation. I have seen many posts on vehicle forums where people have replaced what they believed to be a faulty alternator, only to find that it is the drive circuit in the ECU that has failed.

In the olden days, by rotating the alternator at a sufficient rpm would give an output voltage from a stand-alone functioning unit. Now you might need to feed the alternator with whatever signals it is expecting from a dedicated vehicle ECU – making your proposed repair business trickier than you might have anticipated.

 

Having been in the alternator rebuilding business for a number of years, I can tell you that there are a number of simple scopes out on the market that will handle your needs. You can pick up used Snap on scopes (Vantage , Modis and the MT1665) come to mind. There are many other companies such as Autel and Fluke that build nice automotive scopes and small handhelds like Uscope. These are all built for HD use in all climates. PM me if you would like more information. I think you would be restricting yourself by buying the Brise unit and a good scope in an automotive electrical business is a must have.

 

When I started driving (back in the 1970s), it was common practice to buy an exchange alternator to replace a failed unit. For the more adventurous you could buy a replacement diode pack, carbon brushes or voltage regulator (as required).

There were a limited number of variants based on the alternator mounting arrangement and current rating of the unit.

Fast forward to today, and many vehicle alternators rely on the ECU to provide the voltage/current regulation. I have seen many posts on vehicle forums where people have replaced what they believed to be a faulty alternator, only to find that it is the drive circuit in the ECU that has failed.

In the olden days, by rotating the alternator at a sufficient rpm would give an output voltage from a stand-alone functioning unit. Now you might need to feed the alternator with whatever signals it is expecting from a dedicated vehicle ECU – making your proposed repair business trickier than you might have anticipated.

Hi hymie

The test bench is fully computerised and produces the ecu signals the alternator requires . Com signals and dfm pulses.

I just want a scope to show give me a waveform to show up any diodes that are degrading or any other things breaking down but pass on the test bench.
Belts and braces sort of thing.

 

Having been in the alternator rebuilding business for a number of years, I can tell you that there are a number of simple scopes out on the market that will handle your needs. You can pick up used Snap on scopes (Vantage , Modis and the MT1665) come to mind. There are many other companies such as Autel and Fluke that build nice automotive scopes and small handhelds like Uscope. These are all built for HD use in all climates. PM me if you would like more information. I think you would be restricting yourself by buying the Brise unit and a good scope in an automotive electrical business is a must have.

Hi bwilliams60

Thanks for the information. So I need an automotive oscilloscope?

If I was to purchase a different scope rather than the brise could it be used to diagnose starter motors on the test bench? I read somewhere online about a shop using a scope on starter solenoid.

I have seen the dedicated solenoid testers but they are out of my price range.

 

Hi hymie

The test bench is fully computerised and produces the ecu signals the alternator requires . Com signals and dfm pulses.

I just want a scope to show give me a waveform to show up any diodes that are degrading or any other things breaking down but pass on the test bench.
Belts and braces sort of thing.

That’s good – at least you have considered this.

Besides using a scope to observe the output voltage, I’d recommend your set-up has the capability to load the alternator – demonstrating the claimed output current.

Again back in the day, alternators might have had an output current rating less than 20A, I believe that the alternator in my Jeep has a rating of 168A (that’s over 2kW).

 

That’s good – at least you have considered this.

Besides using a scope to observe the output voltage, I’d recommend your set-up has the capability to load the alternator – demonstrating the claimed output current.

Again back in the day, alternators might have had an output current rating less than 20A, I believe that the alternator in my Jeep has a rating of 168A (that’s over 2kW).

Yes the test bench we have ordered has a variable load up to 200A . An older bench I bought proved useless as it' load bank was 60A and it couldn' test any of the new ecu controlled alternators. I ended up using its vice and making a test rig with a variable speed motor, test lamp, carbon pile load and a handheld ecu regulator tester for the modern smart alternators.

 

Yes the test bench we have ordered has a variable load up to 200A . An older bench I bought proved useless as it' load bank was 60A and it couldn' test any of the new ecu controlled alternators. I ended up using its vice and making a test rig with a variable speed motor, test lamp, carbon pile load and a handheld ecu regulator tester for the modern smart alternators.

Once you buy a scope, the best way to find out how to use it is play with it – with typical input voltages you want to observe.

Most scopes use bnc connectors for the inputs – with typical scope probes having quite small attachments (probes & croc clips), not suitable for automotive applications.

I would recommend you buy one of the items below – allowing easy connection to 4mm banana leads.

https://www.ebay.co.uk/itm/BNC-Male...900241?hash=item3affdee291:g:bg8AAOSwyWZZXFj-

https://www.ebay.co.uk/itm/BNC-Male...116628&hash=item3d667e062c:g:4ccAAOSwVttbB~Ga

You might also consider buying one of these, allowing you to see the current draw on the scope trace.

https://www.ebay.co.uk/itm/Hantek-C...432995?hash=item2aaad0bce3:g:bjIAAOSwc~5bEkV~

 

Hey Bigjon. I would strongly recommend something like a Vantage scope and there is a whole Youtube section on how to use it with Scanner Danner. It is a little rough around the edges but you will see that the scope itself is very easy to use and will do everything you need it to do. When I was rebuilding, our equipment was pretty thorough as far as testing components before they were put together and generally the finished product reflected the care we took in selecting the parts that went into it. I never scoped any of our alternators and never had problems with ripple voltage (only using and AC voltmeter) but I think what you are doing is great. It is good to see someone trying to keep the business going as offshore and Big Box have made it difficult for people to survive in the industry. Buy your fast moving stuff and build the specialty stuff. That will keep you in business.
As for the scope, Vantage is easy to hook up, easy to use and will take a shop environment very easily. A benchtop oscilloscope looks nice but not practical for your purpose.
To answer your question about starters, absolutely. Motors of any type are easily diagnosed and you can store your waveforms for future reference with some scopes which is a great way to create a reference library.

 

Hi
Thank you for the reply.

This is the link to the website.

www.brise.co.uk/Digital-Waveform-Monitor-CVA2.html

Having taken a look at your link – the Brise unit looks well over priced for what it does.

You could buy a far superior scope for much less money – which might serve you better.

With a 2 channel scope you could observe the voltage & current traces simultaneously, giving a much better indication of alternator issues.