Hi electronicsman,
I couldn't understand, what do u mean by motor applications ?
Whether it is power analysis or PWM control or it can be anything.
But any how, there is a lot of good news, no oscilloscope is specific for a motor aplication, unless it involves a electro-mechanical application like tachometer.
Also you have mentioned a low cost one.
So I here by will give you some guidelines to choose a best oscilloscope for your application.
Three main parameters to choose an oscilloscope (DSO)
* Bandwidth
* Sampling Frequency
* Memory Depth
* Waveform Refresh Rate (New feature)
Bandwidth :
It is the maximum frequency that the oscilloscope can capture.
For example a 100MHz oscilloscope cannot capture more than 100MHz frequency, that is it starts attenuating from there after
But the real worst case is, it is suggested to buy two to three times more the bandwidth you actually require, since all oscilloscopes are not true-bandwidth. It can capture the defined bandwidth only for the synchronous waves
Sampling Frequency :
It tells you, how fast the analog signal is sampled into digital. It determines the accuracy over the captured wave while you do all wave zooming. It also determines how reliable are the abnormalities are captured
Memory Depth :
Memory depth will be of prime importance in deep capturing of waves and analysis. memory depth is nothing but the record depth. So higher the memory depth, you can record more waves in time being.
Waveform Refreshment Rate determines how fast the scope recovers from the dead time, that is a lesser dead time meaning a higher refreshment rate.
An optimum oscilloscope sufficient for all usual applications would be
Bandwidth : 100MHz
Sampling rate : 1Gsam/s
Memory Depth : 500Kpts
Now Keysight (Agilent) and Tek are in heavy marketing competition, offering scopes with optimum cost.
There are lot of other manufacturers too
If you are too cautious about cost, you can afford low cost chinese make like Hantek