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advice on capturing spikes with a Rigol scope

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Simon:
The company i work for has developed an airconditioning system for another company who build military vehicles. We have some issues along with a dispute over blame as it seems that the vehicles system has some spike/back EMF spike going around and damaging some of the more sensitive things (like a thermostat that has no inbuilt protection). Having established the existance of the spikes the blaming game has begun and so I have been tasked to recreate the setup of just our air conditioning equipment (by rigging up the same harnessing that the vehicle uses to power and control the various parts) and put it to test to see if our equipment is the cause of any power spikes when things like fans/blowers and other high power inductive devices are switch on and off. Clearly this means non repetitive signals so i need to "capture" them with my digital scope. what is the best way of doing this ? as far as i know the Rigol scope can be set up to capture anything that occurs over a certain voltage. alternatively I could replace the manually operated switches with relays but that would only generate low frequency at which point i might as well sit there and press pause when a spike shows.

I'm also having trouble saving waveforms on my scope. the instructions are a bit vague and i'm getting rather lost, I take it that bitmaps are the best format to save in

marianoapp:
set the trigger to single shot mode and the scope will stop as soon as the signal meets the trigger condition.

anyway be careful because those back EMF spikes can reach very high voltages and you don't want to damage your scope..

saturation:
I don't have a Rigol, but I know this is a job for a triggered event recorder. 
The Fluke 289 can do this, and its portable for on the road use.



The lowly Velleman handheld HPS10 can do it too, it can monitor up to 36 hours. 

On the Fluke 85/87 series, to capture if such an event occurs, I use the min-max setting.  It won't tell you when it happened, or what caused it, but if you're measuring 12V and there's a spike of 50V DC, then something is clearly wrong, and specs claims it can catch transients within 250 uS duration.

http://us.fluke.com/fluke/caen/Digital-Multimeters/Fluke-80-Series-V.htm?PID=56135

What matters between them all is the speed of capture, which is ~ to its frequency response.

Simon:

--- Quote from: marianoapp on April 22, 2010, 07:54:13 pm ---set the trigger to single shot mode and the scope will stop as soon as the signal meets the trigger condition.

anyway be careful because those back EMF spikes can reach very high voltages and you don't want to damage your scope..

--- End quote ---

hm good point, will 400 V cope ? I could try asking for some X100 probes ? make it 4000 V

Simon:

--- Quote from: saturation on April 22, 2010, 08:31:09 pm ---I don't have a Rigol, but I know this is a job for a triggered event recorder. 
The Fluke 289 can do this, and its portable for on the road use.



The lowly Velleman handheld HPS10 can do it too, it can monitor up to 36 hours. 

On the Fluke 85/87 series, to capture if such an event occurs, I use the min-max setting.  It won't tell you when it happened, or what caused it, but if you're measuring 12V and there's a spike of 50V DC, then something is clearly wrong, and specs claims it can catch transients within 250 uS duration.

http://us.fluke.com/fluke/caen/Digital-Multimeters/Fluke-80-Series-V.htm?PID=56135

What matters between them all is the speed of capture, which is ~ to its frequency response.


--- End quote ---

Well it is down to the equipment i have already

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