The USB oscilloscope based on our
DAQ board.
Beside ordinary oscilloscope functions it is also equipped with data logging, spectral analyzer and voltage meter features.
In the following we enlist weaknesses and advantages of the USB oscilloscope with respect to a traditional one (TDS 1012B, for example).
Disadvantages:
 | Low bandwidth: 1.5 MHz |
| Needs a laptopt or a PC with USB 2.0 for operation |
Advantages:
| Very good dynamic range: 16 bits. |
| Very low noise level: 1 LSB (RMS). |
| Much better display: a PC or laptop monitor. |
| Unlimited zooming of any signal segment or of its power spectrum. |
| Number of channels is just a number of devices connected to USB ports: 4 max. |
| Powerful noise reduction facilities: see "PERFORMANCE". |
| Its value and functionality increases in time at no cost: free software upgrades for all customers. |
| Additional functions: data logger, voltage meter (up to 8 digits) and data analyzer. |
| One can add a custom functions: open-source software in C++. |
Average over samples
One of the nice features of the oscilloscope is the averaging over samples function. It helps reducing noise of a signal.
In ordinary, even good brand, oscilloscopes one can fight noise by using averaging over scans. Unfortunately, for such an averaging to be really noise indpendent the precise trigger time point is necessary which is impossible to get for noisy signals. Although, the averaging over scans decreases noise, it removes small regular signal parts as well.
Averaging over samples is better in that respect. See the example bellow.
Above, there is a signal with some noise. If it is averaged just over 10 samples a picture like the one bellow shows. The noise is reduced and a train of little bumps over the signal is revealed.
Such details will not be visible on a regular oscilloscope.
FFT
One can use the oscilloscope for a Fourier analysis of a signal. With just one button one can switch between time ...
... and frequency domains.
You can get a glimps of the oscilloscope quality by inspecting the power spectrum of the sawtooth signal from the previous screenshot in logarithmic scale.
There are over 30 harmonics clearly visible in the plot!
The device is well suited for educational purposes. Using it one can learn about Fourier transforms, noise reduction techniques, sampling speed to resolution conversion and spectral filters on real world signals.
