Anyone bought one of these pocket oscilloscopes?

[daklone]

Has anyone got one of these cheap little digital scopes?



There's loads of different suppliers for them, but they're all the same bit of kit I think.

Thought I might give it a try for casual fault-finding, and wondered if anyone had one and what they thought of it?

[VW]

I have an oscilloscope and ive never had reason to think it could ever be of use on a car. That may be my lack of experience, or my simple old cars?
What do you want to do with it?

[dodgerover]

SOC - scary old cortina did a few excellent posts years ago about fault finding with an oscilloscope.

[daklone]

They are useful if your car is modern enough to have an ECU, VW. Some signals are not simply on or off so a multi-meter isn't good enough to see what's going on.

[VW]

That makes sense. Only cars ive had with an ecu i just get my friend to scan.

[truckdoctor]

Sept 27, 2019 18:01:09 GMT VW said:

That makes sense. Only cars ive had with an ecu i just get my friend to scan.

I used a mains powered one in the 90's for engine management defects and can say they are worth there weight in gold if you know how to use them. If you can stretch to 2 channel with data logging then all the better. They
are great for looking at dynamic circuits,(waveforms).

[bmcnut]

I have nothing useful to add, but if youve never heared of oscilliscope music, I still have nothing useful to add.

[VW]

Sept 27, 2019 20:19:47 GMT truckdoctor said:

Sept 27, 2019 18:01:09 GMT VW said:

That makes sense. Only cars ive had with an ecu i just get my friend to scan.

I used a mains powered one in the 90's for engine management defects and can say they are worth there weight in gold if you know how to use them. If you can stretch to 2 channel with data logging then all the better. They
are great for looking at dynamic circuits,(waveforms).

Ive only ever used it when building hifi amplifiers, no idea when it comes to engine management etc 😂

[Waxoyling Lyrical]

I bought one a couple of years ago, mostly because I was so impressed it was just the size of a mobile phone, compared to the huge desktop contraptions they used to be!

I rarely use it on cars, but as stated above, it lets you see what's going on in terms of oscillation waveforms (sine waves, square waves, etc.) which a multimeter won't generally display (aside from perhaps, a flickering analogue meter needle or constantly changing digital display reading which won't tell you much).

You can also use the scope to measure voltage levels, so for instance, you could see how the battery voltage drops if you switch on headlamps, etc. Potentially also useful to check the output of the alternator...

[gryphon]

Don't need a scope on a car often, but when you do they're invaluable! A multimeter won't pick up voltage spikes, or brief drops that can cause something to reset... Or even just testing the output of a crank/cam sensor.

I can't speak for the little hand held ones, but I have a cheap Hantek USB one for car work. It lags at high sampling rates, which I imagine most cheap ones will, but you do get everything on a nice big laptop screen and it is more than good enough for fault finding and debugging. After all, speed of signals from an engine at 7k RPM is peanuts compared to most electronics.

If you get the little one I'd be interested to know how you find it, pocket size does appeal.

[daklone]

What's the Hantek like?

The problem with these little ones is low analogue bandwidth and lots of averaging it seems. I've watched some YouTube videos showing them with as little as 80kHz bandwidth and obviously heavy averaging going on

[gryphon]

It covers the basics.

Honestly I haven't tested the bandwidth... I have a sig gen but it's buried in the attic! Haven't used it since uni.

Fastest thing I have tried to use it with was a 32kHz PWM signal which on paper a 20MHz scope shouldn't think twice about but the display went very laggy - it felt almost like there was a bottleneck in the data it was passing to the computer at a high sample rate (Can't remember what that sample rate was, but it was nowhere near the advertised capability). It gave an interpretable waveform, but there was a lot of ringing on that line so I have no idea how much of what I was seeing was down to the scope, and how much was the signal.

We have proper scopes at work that I can generally borrow if I need a good one, so I've relegated the hantek to slower/more basic uses such as debugging car electronics, which it's perfectly adequate for (not tried any network work though). Cheap, packs away small and I probably use it once every 6 months or so - If I kill it I'll probably buy another, or try a different cheap one.

One thing to note is that there are a few alternate PC software options for it that might be worth trying.

[daklone]

Hmm, I'm thinking I'd be better off keeping an eye on ebay and gumtree and trying to pick up a bargain 'proper' scope.

I like the idea of a little portable one, but it would always be a niggle in the back of my mind about whether it was really up to the task

[nomad]

I've looked at (not bought) "USB oscilloscopes" a few times, maybe something to think about ?
My thinking as a total novice is that most laptops & tablets have a lot more processing power than 'scopes a few years old   

[Clamity]

I haven't bought one yet but last time I was looking at these Hantek were the best value for money out of Chinese made stuff. There's about 4 different versions, 72MHz or 42MHz and with or without a signal generator function. I think any would be fine for car use.