pc oscilloscope

[a.wayne]

Hello Guys ,

Looking for a PC based scope , seeing the info here is 2 yrs old maybe time for an update , any recommendations ?

Regards,

 

[johngalt47]

No recommendations but I'm interested in protecting my sound card from high voltage when using the scope probe.

 

[FastEddy]

'Scope probe protection. Seek dual, series, reversed polarity parallel, pairs of Sckottki Diodes.

. |---|>--|>---|+
-|---<|--<|---|

... across the (probe) input work very well for this = low capacitance, low impedance, fast response to any signal above ~ 3 v. AC or DC. (Reference: see input circuit diagram of some common CMOS switches ... originally used to eliminate possible input static discharge into a chip or chip set. Common on early computer motherboard and bus backplane I/O connections.)

 

[bikinpunk]

Expensive, but from what I'm told by a friend, it's good:
USB Instruments “Stingray” Oscilloscope Review

TrueRTA also has an oscope feature built in that's nice. You'll have to make sure you build a voltage divider so you don't blow the inputs of your soundcard. That's the cheaper option.

 

[ganzziani]

I have put together an oscilloscope comparison table where you can filter and sort devices to find the one best for your needs: Digital oscilloscopes for hobbyists | Resources

 

[milen007]

'Scope probe protection. Seek dual, series, reversed polarity parallel, pairs of Sckottki Diodes.

. |---|>--|>---|+
-|---<|--<|---|

... across the (probe) input work very well for this = low capacitance, low impedance, fast response to any signal above ~ 3 v. AC or DC. (Reference: see input circuit diagram of some common CMOS switches ... originally used to eliminate possible input static discharge into a chip or chip set. Common on early computer motherboard and bus backplane I/O connections.)

hi FastEddy

is this the schematic of what do you mean?
Interface Circuit for PC Soundcard Oscilloscope

any type of diode will do?

thanks
erwin

 

[FastEddy]

... is this the schematic of what do you mean?
Interface Circuit for PC Soundcard Oscilloscope ...

YES! and it is a better graphic than mine as well.

The double diodes "clip off" every part of the signal that exceeds +/- 1.2 volts, AC or DC.

 

[wakibaki]

I've used a Picoscope 2104 which is 10MHz and costs £125. I thought it was pretty good because of the portability. The probe is part of the unit, it just went in the carry bag with the laptop and my other tools. Good for diagnosing low speed digital comms, slow micros like PICs.

The disadvantages... it's only single trace, it's good for only 20V, I destroyed mine in a moment of inattention and Picoscope were unable to repair it, I had to replace it. The fact that I replaced it says something though.

w

 

[CopperTop]

it's good for only 20V, I destroyed mine in a moment of inattention and Picoscope were unable to repair it, I had to replace it.

What sort of probe were you using? A x10 would have inserted a 9M input impedance in series with the input, which would be a good thing, no doubt.

But even at x1 I would have imagined that it would be possible to design an input stage protected to several hundred volts, especially on a slow-ish scope. It seems like a basic flaw in a piece of test equipment that's bound to get prodded around in mains powered equipment.

 

[nigelwright7557]

I like stand alone oscilloscopes.

I wouldnt risk connecting anything to my pc.

I sometimes look at high voltages on my scope but the thought of high voltages getting into my pc horrify me.

 

[CopperTop]

I like stand alone oscilloscopes.

I wouldnt risk connecting anything to my pc.

I sometimes look at high voltages on my scope but the thought of high voltages getting into my pc horrify me.

I would hope that it would be completely isolated: DC-to-DC converter if powered by the USB, and opto-isolation for the data link.

 

[cyclecamper]

I'm pleased I got some real money on eBay for my old Heathkit junk I built many years ago, truly obsolete long ago. Now I sure would like to replace it with something better to connect to a PC. I want cursor measurements on-screen, memory, high-frequency resolution, dual-trace (at least) etc.