Products > Test Equipment
Hantek DSO2xxx schematics
morgan_flint:
Hello, pcprogrammer! Great job!!
If you think it's worth it, and after you consider the work is finished, maybe it would be a good idea to create a single .pdf with all the schematics where the labels, components, etc. would be in searchable text form. I'm not familiar with the program but maybe just printing to pdf from EasyEda would do the trick.
The main advantage would be that it would be possible to search for the different circuit labels so it would be fast and easy to follow the signal path between the different sheets.
Thank you very much for your work!!
morgan_flint:
--- Quote from: pcprogrammer on June 30, 2022, 05:31:22 am ---...I found some weird stuff done in the scope with the power supply TR line. Know it is a 50Hz signal (might be 60Hz in countries with this mains frequency) from the Hantek threads. It is routed to a 74 Schmitt trigger buffer and then routed to the FPGA on pin 128. Nothing weird there, but the output of the buffer is also used to control pull ups on the clock and load line for the led 74HC595 shift register. (U4 in the LED schematic)
Why I don't know, but it means they can only clock this shift register when the TR signal is high :-//
--- End quote ---
Could this be some kind of 50-60 Hz PWM for the LEDs in the display board?
Talking about battery power conversions, I remember somebody posted on one of the other threads that, in the absence of the 50-60 Hz signal from the power supply, the scope wasn't working correctly. Maybe it's related to this strange use of the signal. But I also remember that I experimented with disconnecting the TR from the power supply to the main board and didn't notice any misfunctioning...
P.S: Here is the post where crysti reported the problem and here is the post where I said I did that experiment. The previous post includes a simplified power supply schematic
pcprogrammer:
Hi morgan_flint,
you are welcome. and yes I can make a single PDF per board. I'm gathering datasheets in a github repository and will add the EasyEda files there too.
https://github.com/pecostm32/Hantek_DSO2000
But I have to finish the analog schematics first, which may take some time due to laying a terrace with "lauze" which are thin stones. A hell of a job that takes a lot of energy. Unfortunately the guy we found to do the job for cheap got a MRSA infection in his right hand and is no longer able to do the job, so have to do it myself. :palm:
Due to an overlap in component numbering I have to keep the two boards in separate projects, but I guess that is not such a big of a deal when one needs to work on the scope.
As soon as it is done I will post it here.
Regards,
Peter
pcprogrammer:
--- Quote from: morgan_flint on July 07, 2022, 09:47:37 am ---
--- Quote from: pcprogrammer on June 30, 2022, 05:31:22 am ---...I found some weird stuff done in the scope with the power supply TR line. Know it is a 50Hz signal (might be 60Hz in countries with this mains frequency) from the Hantek threads. It is routed to a 74 Schmitt trigger buffer and then routed to the FPGA on pin 128. Nothing weird there, but the output of the buffer is also used to control pull ups on the clock and load line for the led 74HC595 shift register. (U4 in the LED schematic)
Why I don't know, but it means they can only clock this shift register when the TR signal is high :-//
--- End quote ---
Could this be some kind of 50-60 Hz PWM for the LEDs in the display board?
Talking about battery power conversions, I remember somebody posted on one of the other threads that, in the absence of the 50-60 Hz signal from the power supply, the scope wasn't working correctly. Maybe it's related to this strange use of the signal. But I also remember that I experimented with disconnecting the TR from the power supply to the main board and didn't notice any misfunctioning...
P.S: Here is the post where crysti reported the problem and here is the post where I said I did that experiment. The previous post includes a simplified power supply schematic
--- End quote ---
I don't think it is a PWM for the LED's. It only affects the clock and load signal for the LED shift register. No idea what is done with the signal in the FPGA, but it might well be that if the signal is tied to VCC it just works. When tied to ground the LED's may or may not function. Depends on the output strength of the FPGA. Pull-ups versus pull-downs.
I ordered a longer flat cable for between the main board and the user interface board to be able to do measurements on the scope. Once it gets here I plan to look into these things.
pcprogrammer:
Did channel 2 and hope the redrawing makes it more readable.
I'm not to familiar with the user interface and have a question about two of the control signals.
The first control signal switches the input relay and I named it CHANNEL2_FILTER, but I'm not sure to what menu item this belongs to. Then there is also a control signal I named CHANNEL2_X, which enables a capacitor to ground right after U28, so also looks like a filter. But again the question which menu item this belongs to.
Still need to cleanup channel 1 and the control signals sheet and number the sheets before it is done.
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version