Every once in a blue moon I need something resembling an oscilloscope, but usually with 5 or 6 channels, portable, and with pretty minimal resolution and bandwidth requirements. A USB DAQ looks like it would fill the bill. It would plug into an old laptop (for now), so it has to work with USB 1.1. Also, ideally, it would have an open interface, so if need be I could program it.
In other words, something like this:
http://labjack.com/u3/specs
but with a wider voltage input range. The latest problem is diagnosing an automatic transmission issue, where I need to simultaneously measure the PWM going to a couple of solenoids, and the DC signals coming back from 4 sensors. So it must measure up to at least 20V and also accept voltages well beyond that without blowing up the inputs. 10 bit resolution would probably be enough, but 12 would be better. A sample rate of 40 kHz should do. (I think. Anybody know what the base frequency is for the PWM waves fed to AT solenoids?) I don't expect to be able to use this for diagnosing motherboard waveforms, or anything else fast, just audio frequencies and down.
It should also be cheap - this is for hobby use, so I can't justify a lot of $$$.
Suggestions?
In a couple of previous cases I was able to get by with making "recordings" using audacity from the audio input through a diode clamped adapter. That works OK for AC, but not at all for DC, and of course it was limited to two inputs.
I did look through the oscilloscope thread here: https://www.badcaps.net/forum/showthread.php?t=6062
but most (all?) of those needed to be plugged into 120/240 VAC.
In other words, something like this:
http://labjack.com/u3/specs
but with a wider voltage input range. The latest problem is diagnosing an automatic transmission issue, where I need to simultaneously measure the PWM going to a couple of solenoids, and the DC signals coming back from 4 sensors. So it must measure up to at least 20V and also accept voltages well beyond that without blowing up the inputs. 10 bit resolution would probably be enough, but 12 would be better. A sample rate of 40 kHz should do. (I think. Anybody know what the base frequency is for the PWM waves fed to AT solenoids?) I don't expect to be able to use this for diagnosing motherboard waveforms, or anything else fast, just audio frequencies and down.
It should also be cheap - this is for hobby use, so I can't justify a lot of $$$.
Suggestions?
In a couple of previous cases I was able to get by with making "recordings" using audacity from the audio input through a diode clamped adapter. That works OK for AC, but not at all for DC, and of course it was limited to two inputs.
I did look through the oscilloscope thread here: https://www.badcaps.net/forum/showthread.php?t=6062
but most (all?) of those needed to be plugged into 120/240 VAC.
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