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Just training of DDRx memory interface can take several seconds all by itself depending on the interface and DDR revision. The only realistic way of achieving boot times anywhere close to requested is a suspend-to-RAM, but that requires uninterrupted power supply to preserve it's contents.
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Quote
inserting anything but a drill bit into a drill chuck.
And whats wrong with that?
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Test Equipment / Re: SDS800X HD Bugs/Wanted Features
« Last post by electronics hobbyist on Today at 01:54:32 am »
Save button does nothing in the Bode plot, it should make the usual screenshot.
Which file format and to Internal or USB ?

Save image based on Bode Plot print settings.
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Test Equipment / Re: Hacking the Rigol DHO800/900 Scope
« Last post by AceyTech on Today at 01:52:13 am »
Edit: a 35*35 mm² heatsink (with less than 35 mm height, I assume?) will be far from 1 K/W -- more like 10 K/W. You would need a much more hefty heatsink to passively cool the DHO.

On closer examination;  While that SBC itself is fanless, their temp spec says "@0.7m/s Air Flow".,   BTW it looks  significantly shorter than 35mm height.  They also don't have a FPGA running balls out, contributing to the heat load.

Incidentally, this is a very warm product, naturally.  Uncomfortably so, IMHO.  When I unplug a USB connector it's HOT., BNC's are as well.  I forgot to measure the temperature on the connectors during my fan testing, but the last mod I did cooled the I/O's considerably.

BTW: @shapirus
I watched that video you mentioned, and have some issues with his methodology.  I'm not saying it was flawed per se', but I just can't put much confidence in some of his findings in general.  Ex: when Rigol did their HALT testing, I doubt they turned it up on end, dumping heat into the power supply section.
  -From what I've observed, these scopes don't really need much of an excuse to reboot.  Sometimes, I'll look over at my DHO because it's clicking and flashing in the middle of a reboot cycle.  For no reason!
(Before anyone asks: ^that's before I opened it)
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At the input is an RC differentiator (R2-C3) that I found out is required, since the NE556 one-shot will not terminate while the input is left low.
But your circuit shows that the input (to the 556) is pulled low (to zero volts) by R2.
Where is the zero-volt reference on the your scope trace? To me, it looks like the input to the chip is being driven negative by a volt or more, it then settles-out at about -0.6v (one silicon junction voltage drop below zero volts). I would suggest that the 1.5mS is the time it takes for the chip to recover from having its inputs forced below the zero (ground) reference.

The minimum you need to do is change R2 to pull-up to Vcc such that the chip is not permanently triggered. You might then consider some means of preventing the input from exceeding Vcc (which might also have a negative impact on the chip).
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So you would have a certificate on the server, preferably not self-signed.

Can you explain what the advantage of having it not self-signed is?
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Even if LM337 or the transistors were wired wrong, there is a 2.5 kΩ resistor in the path. With 35 V directly across it, the current is limited to 14 mA. Power on this 120 Ω resistor is below 25 mW. Something is not adding up in that description.

As for wiring: make sure LM337 is connected right. The component is very similar to LM317, but their pinout is different. TO-220 package for LM337 has input and output pins swapped compared to LM317.
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General Technical Chat / Re: Youtube "how to" videos are mostly useless
« Last post by xrunner on Today at 01:22:42 am »
Perhaps I've been lucky lately, but I've found quite a few very good videos on a variety of subjects.

Installing a Micro Air Easy start
How car painters blend paints on a body repair
Pakistani mechanics and how they repir big equipment
Crimping wire connectors (various kinds)

And my new favorite - LaurieWired - which deals with how malware and such things are reversed engineered.  :-+
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Are you sure R1 and C1 are the values you think they are? Did you try another set? Maybe you have a bad connection on a breadboard?
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Test Equipment / Re: HAMEG HM1000 - Vertical position knobs
« Last post by EvgenyG on Today at 01:15:55 am »
You can order new ones from https://www.sky-messtechnik.de/
I've replaced all encoders in my Hameg scope and it works better than new now!
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