I had my DSO-220 scope hooked up to a 12v signal(testing a boost controller) for a while and all was well when all of the sudden Windows dropped the device(you know that sound when you unplug something). To make a long story short it fried itself($220) and my USB-to-Serial adapter. It's a miracle the ports on my laptop are still good.
After I took it apart there was the familiar but faint fried smell, but I couldn't find anything visible wrong with it. During inspection I found all sorts of diodes that were added after the board was designed/built.
I had it set to DC but was using + ground, that shouldn't have caused the melt down should it? Says 36v max.
-sean
BEWARE Cheap USB scopes!
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BEWARE Cheap USB scopes!
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Re: BEWARE Cheap USB scopes!
Flyback from a solenoid can go well above 36V which is what I would suspect here.
Jean
Jean
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Re: BEWARE Cheap USB scopes!
True, but I had a 2 amp diode to soak flyback, unless that wasn't enough.
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Re: BEWARE Cheap USB scopes!
You would still think they would have protection so that power isn't back fed to the USB port.
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Re: BEWARE Cheap USB scopes!
Gutted :-(
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Re: BEWARE Cheap USB scopes!
I'm kinda leaning towards this http://www.saelig.com/miva/merchant.mvc ... egory_Code. I know I know didn't I learn the first time, but it looks significantly better than my last one
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Re: BEWARE Cheap USB scopes!
I would think that 2A should be enough but maybe it's just not fast enough. But I agree with you that in any case power shouldn't be fed back to the USB port. That's simply stupidly bad design.
And thank you for the warning because I also have a cheap USB scope.
Jean
And thank you for the warning because I also have a cheap USB scope.
Jean
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Re: BEWARE Cheap USB scopes!
There's 99 ohms between the probe ground and the USB ground pin.
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