Products > Test Equipment
Hantek HDG2002B AWG: 5Mhz or 100MHz? Let's see!
robert_:
Still fails even after full cal on both channels. Did also fail right out of the box. Probably doesnt mean much, as everything works so far.
As for the newer firmware, it seems to be somewhat more stable, expect for the one time it rebooted at my first cal attempt, i didnt witness any crash yet.
Oh, and now for some bad news: The whole thing is seriously dangerous.
The power supply is constructed with totally inadequate isolation between primary and secondary, and the secondary side is NOT grounded. So in case the isolation fails, the outputs will be live.
Why? Have a look at the transformer, trough the slits at the top of the bobbin. Primary and secondary windiwngs are made with normal magnet wire (approved TIW looks different), with no margins on both sides of the bobbin and only one layer of thin tape in between. As the secondary is not grounded, it would have to fulfill reinforced isolation, ie 3kV proof voltage, and (depending on material group, PD and installation category) at least around 5mm of creepage distance, and 3 layers of tape. What it has is pretty much ZERO creepage. From my experience, crap like this break down with <2kV, often less than 1kV when hot. Spikes of that magnitude are not uncommon, especially on 230V mains.
Also, the isolation is crossed by a 4.7nF "Y1" capacitor that looks too small for its ratings. Looks more like a Y2 from the ceramic thickness.
Apart from that questionable part, this capacitor results in the non-grounded outputs having significant voltage (and quite some peak current when shorted) to ground, which can kill whatever circuit it is connected to (and you can even feel it).
At least, the secondary common needs to be solidly grounded to improve safety for now, but Hantek really has something to explain as they stuck a CE mark on a non-compliant device.
fremen67:
--- Quote from: robert_ on June 26, 2015, 10:07:27 pm ---As for the newer firmware, it seems to be somewhat more stable, expect for the one time it rebooted at my first cal attempt, i didnt witness any crash yet.
--- End quote ---
Could you give more details one your firmware version? Did your device came with a new version or did you upgrade it yourself?
--- Quote from: robert_ on June 26, 2015, 10:07:27 pm ---Oh, and now for some bad news: The whole thing is seriously dangerous.
The power supply is constructed with totally inadequate isolation between primary and secondary, and the secondary side is NOT grounded. So in case the isolation fails, the outputs will be live.
Why? Have a look at the transformer, trough the slits at the top of the bobbin. Primary and secondary windiwngs are made with normal magnet wire (approved TIW looks different), with no margins on both sides of the bobbin and only one layer of thin tape in between. As the secondary is not grounded, it would have to fulfill reinforced isolation, ie 3kV proof voltage, and (depending on material group, PD and installation category) at least around 5mm of creepage distance, and 3 layers of tape. What it has is pretty much ZERO creepage. From my experience, crap like this break down with <2kV, often less than 1kV when hot. Spikes of that magnitude are not uncommon, especially on 230V mains.
Also, the isolation is crossed by a 4.7nF "Y1" capacitor that looks too small for its ratings. Looks more like a Y2 from the ceramic thickness.
Apart from that questionable part, this capacitor results in the non-grounded outputs having significant voltage (and quite some peak current when shorted) to ground, which can kill whatever circuit it is connected to (and you can even feel it).
At least, the secondary common needs to be solidly grounded to improve safety for now, but Hantek really has something to explain as they stuck a CE mark on a non-compliant device.
--- End quote ---
Any modification to suggest?
robert_:
My HDG came with the SW 1.00.3 installed.
Well, as the PSU is crap, the only way to sort of inprove the situation is to solidly connect the secondary common (BNC shield etc) to the earth conductor. With hopefully intact grounding in the IEC cable and bulding installation, the risk of dangerous failiure is greatly reduced. Now it would blow the fuse when the transformer breaks down, and ther will also be no more common mode voltage on the outputs.
However, the transformer is still not adequately insulated (to comply with IEC60950 or 60010, both of which have pretty identical requirements), as it still would require basic isolation which needs a creepage distance well above zero.
Im going to build my own PSU though, since i want to keep the outputs floating to avoid ground loops. This however requires the digital isolators to be fitted, because otherwise the output will be grounded (not really safely, just noisy) as soon as the USB cable is connected.
Looks like the board was intended to have 2 ADUM2400/3400 series isolators fitted. Pinout matches, and it also seems to be the x400 variant with 4 channels in the same direction.
Also the processor/USB side has spaces for 2 1117 linear regulators to produce 3.3 and 1.8V which are not fitted, as these voltages are supplied by the analog/FPGA side by the 0R resistors. Removing the resistors and installing 2 regulators should resolve that, the 4pin connector for supplying 5V on the processor side is already fitted. 1.8V seems to need the LT1117-ADJ because the feedback divider is already there, 3.3V has no divider and ADJ pin grounded so should get the LT1117-3.3.
fremen67:
--- Quote from: robert_ on June 27, 2015, 05:16:26 pm ---My HDG came with the SW 1.00.3 installed.
--- End quote ---
Would you be able to dump your HDG and post somewhere the files so that I could create a update file? You will find an "upgrade" package in my onedrive that will allow you to backup your nand https://onedrive.live.com/redir?resid=C666E0DC0AF0C9E2!114&authkey=!AMtRrjm2d33uI8Q&ithint=folder%2c (in the backup folder).
--- Quote from: robert_ on June 27, 2015, 05:16:26 pm ---Well, as the PSU is crap, the only way to sort of inprove the situation is to solidly connect the secondary common (BNC shield etc) to the earth conductor. With hopefully intact grounding in the IEC cable and bulding installation, the risk of dangerous failiure is greatly reduced. Now it would blow the fuse when the transformer breaks down, and ther will also be no more common mode voltage on the outputs.
However, the transformer is still not adequately insulated (to comply with IEC60950 or 60010, both of which have pretty identical requirements), as it still would require basic isolation which needs a creepage distance well above zero.
Im going to build my own PSU though, since i want to keep the outputs floating to avoid ground loops. This however requires the digital isolators to be fitted, because otherwise the output will be grounded (not really safely, just noisy) as soon as the USB cable is connected.
Looks like the board was intended to have 2 ADUM2400/3400 series isolators fitted. Pinout matches, and it also seems to be the x400 variant with 4 channels in the same direction.
Also the processor/USB side has spaces for 2 1117 linear regulators to produce 3.3 and 1.8V which are not fitted, as these voltages are supplied by the analog/FPGA side by the 0R resistors. Removing the resistors and installing 2 regulators should resolve that, the 4pin connector for supplying 5V on the processor side is already fitted. 1.8V seems to need the LT1117-ADJ because the feedback divider is already there, 3.3V has no divider and ADJ pin grounded so should get the LT1117-3.3.
--- End quote ---
This is interresting, any pictures for details?
rodlaird:
Sorrt dumb question for Fremen67...
I downloaded your zip file with the various backup and upgrade scripts - loaded afg_HDG2002B_to_HDG2102C.upk on a FAT32 formatted USB and....
...nothing. |O
I get an error -129 when I try to perform the update (or -4 if I retry).
newb error on my part obviously... But advice appreciated...
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