Oscilloscope property Connect to ground
Hi,
what is oscilloscope property Connect to ground? It seems to me that it does nothing. The oscilloscope behaves identically whether it is checked or unchecked and it still has five inputs. The only difference is when it is checked then the input impedance is used in simulation. Is it intended behaviour?
Tested trunk revision 2230.
Hi.
The only difference is when it is checked then the input impedance is used in simulation.
Yes, that is exactly what it does: adding a impedance to ground.
If it unchecked then it just reads the voltage at that point which was the behavior before.
The input impedance behaves strange. When I set the input impedance to 100 Ohm and connect a power supply with 100 Ohm resistor in series to the oscilloscope input and the fifth pin to ground then It works correctly. There is one half of power supply voltage. When I switch the circuit off and on again then it behaves like with infinite input impedance. Moreover when I disconnect the ground from the fifth pin and connect the ground to the second channel the input impedance is also infinity. I expected that there will be positive one third of power supply voltage at channel one and negative one third of power supply voltage at channel two.
How does this settings works for logic analyzer? The oscilloscope has four channels and five pins, but the logic analyzer has eight channels, but only eight pins.
Also when the Connect to ground is unchecked the option Input impendance might be hidden.
Generaly the oscilloscope input impedance in the SimulIDE is not impedance, but resistance. Real oscilloscopes have input impedance which usually consists of 10 MOhm resistance and several pico farads capacitance.
The default value 10 MOhm should be set as 10 MOhm and not 1e+7 Ohm. It looks ugly.
Thank you.
All the issues solved at Rev 2236.
Moreover when I disconnect the ground from the fifth pin and connect the ground to the second channel the input impedance is also infinity. I expected that there will be positive one third of power supply voltage at channel one and negative one third of power supply voltage at channel two.
How does this settings works for logic analyzer? The oscilloscope has four channels and five pins, but the logic analyzer has eight channels, but only eight pins.
Channels are not connected to fifth pin.
This pin works as a reference voltage, that's all.
For Logic Analyzer reference is always 0V.
Generaly the oscilloscope input impedance in the SimulIDE is not impedance, but resistance.
Well.. in this case impedance = resistance because reactance = 0.