Vehicle tracking devices failure.

[premkumar9]

Hi,
We supply vehicle tracking devices. There are some field failures and we suspect the voltage spikes as a reason for this. Is there any way to check whether the wiring of the vehicle is proper and will not cause such damaging spikes?

 

[large_ghostman]

Would it not be easier to make sure the boards can handle the spikes? Why would you want to check the vehicle? Am I right in assuming you want to check the vehicles so you can say this is a problem with the vehicle not the product?

I dont understand what use it is to check the wiring, spikes are likely to be inherent rather than a wiring problem as such. I would assume it wiser to design a product that can cope with an uncertain power input.

 

[premkumar9]

We use tracking devices from a reputed source which meet international standards. But there may be some limits for the spikes thy can handle. How can I know whether this is exceeding in a particular vehicle?

 

[AnalogKid]

By finding out from the manufacturer what spikes it can and cannot handle. Without that data, knowing the spikes in any particular vehicle doesn't tel you what you want to know. For example, the quality of the power systems, such as spikes, surges, dropouts, etc., in military vehicles, aircraft, and ships is defined in MIL specifications. A designer knows exactly what a product has to be able to survive. In you case there probably isn't a single specification, but the manufacturer had to have some performance targets to work with.

ak

 

[jpanhalt]

Tracking down failures that occur occasionally but without a pattern is difficult because you cannot predict which of many vehicles needs to be monitored. Does the same vehicle or user have more than one failure? Let's say you want to install a monitor for the electrical system and wait for a failure. Assuming you have 1000 installations and <10 failures a year (i.e., ≤1%), that would be a very expensive approach. It has been a long time since I calculated what the minimum number of vehicles monitored would be, but my off the cuff guess is that you would have to install the monitor in more than 300 vehicles to approximately a 95% chance of detecting a failure over the course of a year. If you need a result sooner, your best bet would be to install a monitor in every vehicle. That could be a very expensive proposition for a one-time experiment.

Do you have any evidence that the failures are related to electrical noise in the vehicles and are not just random occurrences? Can you put an oscilloscope on a couple of the failed vehicles and the same number of non-failed vehicles and have someone monitor or record the results for a day or two of normal driving? Result may not be statistically valid, but you may find that electrical noise in vehicles of similar type is either the same or vastly different. If the same, that is consistent with random occurrences. If vastly different, then design a follow-up study to pinpoint the cause.

John

 

[audioguru]

I think the standard for car electronics is that it must withstand a "load dump" voltage spike of +60V and -50V.

 

[large_ghostman]

Maybe try adding a small board with zener and resistor, maybe add caps to smooth and if really bad add rectifier. Why not test one vehicle from the ones that burned the system, it will give you an idea how sensitive the boards are. I am inclined to think its a poorly designed board rather than a problem with the vehicles, if you look at it logically then if it was a vehicle problem it would most likely just be a couple and maybe just one model or manufacturer.

Maybe they all use the same alternator or voltage regulator, but whatever way you look at it the boards if designed for vehicle use should handle it no problem. I have a feeling the boards are designed for a smooth 12V max voltage from a bench supply, there cant be many cars and such on the road with **** electrics or the EMCU would also be destroyed, you have to remember that so many vehicles today are jammed solid with electronics, if it was a vehicle problem how come the other systems still work? This is the kind of thing I would be asking rather than whats up with the vehicle.

Do some simple tests on the board like putting 13.7V into it and seeing if it smokes or gets hot, most things run off 5V or less so its likely a problem with the way your board regulates voltage rather than a problem with input voltage

 

[Diver300]

You could see what Jaguar Land Rover demand for stuff fitted to their vehicles:-

https://www.jaguarlandrover.com/emc/docs/requirements.htm

The load-dump requirement isn't particularly harsh as the vehicles have central load-dump protection.

What is the specification for the tracking devices? Would that meet what Jaguar Land Rover test to?

You should analyse a failed device to see if the failed component could have been affected by spikes.

 

[cowboybob]

Hi,
We supply vehicle tracking devices. There are some field failures and we suspect the voltage spikes as a reason for this. Is there any way to check whether the wiring of the vehicle is proper and will not cause such damaging spikes?...

and:

... so many vehicles today are jammed solid with electronics, if it was a vehicle problem how come the other systems still work?...

This is just me musing, but:

I'd also be curious to know if the "field failures" are actually intentional disabling, by whatever means, by the driver(s). When you think about it, who really likes being tracked?...

 

[large_ghostman]

and:

This is just me musing, but:

I'd also be curious to know if the "field failures" are actually intentional disabling, by whatever means, by the driver(s). When you think about it, who really likes being tracked?...

See thats the engineer in you, you forget average person dosnt know what the battery looks like let alone have the goolies to disable something. I doubt its intentional I would go with several meaning that more than 10% fail rate. If its high enough to be more than one maybe two then I suspect the device unless they have sold millions, if they have sold millions then they can afford engineers to do proper testing and wouldnt ask here for our superior opinion

 

[cowboybob]

... See thats the engineer in you, you forget average person dosnt know what the battery looks like let alone have the goolies to disable something. ...

True enough, LG, true enough .

But, I also never underestimate the ingenuity of the truly persistent and devious... .

 

[large_ghostman]

True enough, LG, true enough .

But, I also never underestimate the ingenuity of the truly persistent and devious... .

My dad called them the coffee spillers lol, oopps spilt my coffee on XYZ lol

OMG I have changed

 

[Diver300]

I have heard of attempts to disable tracking devices by disconnecting the battery with the engine running to induce a load dump. That supposes that the load-dump protection on the tracking device is quite poor, so I don't know how successful that has been.

 

[crutschow]

It would seem the proper solution is to add additional spike/overload protection circuitry at the input to the tracking device.
Finding out which vehicles might be causing the problem is not really a solution to the problem.

 

[Mikebits]

I found this really good write up on electrical hazards in automotive. It list the causes and gives protection measures. It also list some of the standards that automotive developers must follow for electrical circuits. a list of some of the standards is pasted below. This is well worth the read.

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0ahUKEwjn8KmS2vXKAhUO8GMKHbPaDMIQFggcMAA&url=https://www.st.com/web/en/resource/technical/document/application_note/CD00181783.pdf&usg=AFQjCNHrDykDd7lz3iDBNjsiwzN9Ktiuwg&sig2=xal95GLXpgs96EKELhOIWg&bvm=bv.114195076,d.cGc&cad=rja

■ ISO 10605 (C = 150 pF, R = 330
– 30 kV (air discharge)
– 30 kV (contact discharge)
■ ISO 10605 (C = 330 pF, R = 330
– 30 kV (air discharge)
– 30 kV (contact discharge)
■ ISO 7637-2
– Pulse 3a: VS = -150 V
– Pulse 3b: VS = 100 V
■ IEC 61000-4-5: IPP = 3 A (8/20 μs)
■ HBM MIL STD 833, class 3 (> 4 kV)

Transils seem to be common for protection.

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0ahUKEwjGzIaJ2_XKAhVBWWMKHb4MBYkQFggoMAE&url=https://www.st.com/web/en/resource/technical/document/datasheet/CD00131990.pdf&usg=AFQjCNHTHLWUIR287mO0NgRHmQsa9BdIrw&sig2=FWrbBAlwI3SBjairB8fq9A&cad=rja

 

[kubeek]

We use tracking devices from a reputed source which meet international standards...

Continuing on what Mikebits said, which standards exactly, and to what degree or what parts of those?
There are loads of standards out there that would make such a device completely compliant when powered from a 12V wall wart, but absolutely not at all when connected to a car power distribution system.

Read the standards, understand them, and if such a device is supplied to you and you have reason to believe the certification is fake test if by yourself if you can and then have it retested by some authority. However if you are producing such a device, search even more thorughly on what is required for it to withstand and make sure it complies, otherwise you might end up on the other side of the investigation. I am almost sure the cars it is installed in are compliant, unless they had some major changes compared to the factory state.

 

[audioguru]

I used a national semiconductor low dropout 5V regulator in my FM transmitter because I want it to continue working when the 9V battery drops to 5.6V. The regulator has +50V load dump protection in case it is used in a car.

 

[large_ghostman]

I thought you supplied them? or are you a re seller? Why do people always turn things into a guessing game!! Why not just say you make a rubbish device that breaks when connected and we want to improve it? Would make life easier than mystery specs and loads of unanswered questions!!

 

[jpanhalt]

I thought you supplied them? or are you a re seller? Why do people always turn things into a guessing game!! Why not just say you make a rubbish device that breaks when connected and we want to improve it? Would make life easier than mystery specs and loads of unanswered questions!!

To whom is that directed?
John

 

[large_ghostman]

To whom is that directed?
John

The OP, but feel free to answer if you like.