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General Technical Chat / Re: Relay trigger when voltage above 13v
« Last post by NiHaoMike on Today at 12:03:30 pm »Use a supply voltage monitoring chip, it will already have many features you want such as hysteresis and deglitching.
Recent Posts
2
Embedded Computing / Re: WINCE question
« Last post by Bicurico on Today at 12:02:55 pm »I don't see any issue. This is the embedded forum and we are talking about WinCE, which is for embedded devices.
The fact that the binaries run on a PC with Windows is within topic, I would say
The fact that the binaries run on a PC with Windows is within topic, I would say
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EEVblog Specific / Re: EEVblog 1612 - Siglent SDS1000X HD 12 bit Oscilloscope Teardown
« Last post by 2N3055 on Today at 12:01:27 pm »Perhaps they forgot to mount the capacitors in your unit.Hi Dave, my 1204X-HD has microphonic inputs.
Wow. Why the difference?
Let them know and they'll happily ship you a couple that you can solder in place...
It is because Dave used 50Ω termination....
It is amazing how easier is to just speak smack instead of looking into facts...
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Power/Renewable Energy/EV's / Re: DIY Battery Bank from Recycled 18650
« Last post by mtwieg on Today at 12:01:14 pm »What are those things in a glass package? Fuses?I assume they're fuses. I'd like to ask them why they're only used on specific cells...
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Projects, Designs, and Technical Stuff / Re: Homebrew Lock-In Amplifier
« Last post by Picuino on Today at 12:00:46 pm »I don't really have much time right now. I am preparing the project for this summer when I will have enough time to assemble and test it.
I want to make a real LIA, which is fast enough to decode sounds in real time (10kHz minimum) from a higher frequency signal.
I don't care if it has a lot of quality, just enough for basic experiments to work. That's why I'm considering making the LIA with cheaper, simpler powered components (amplifiers). The problem is that I can't replace the AD630 with a simpler power supply. Sometimes I consider doing a digital LIA directly, but then I would not have any standard to compare.
I want to make a real LIA, which is fast enough to decode sounds in real time (10kHz minimum) from a higher frequency signal.
I don't care if it has a lot of quality, just enough for basic experiments to work. That's why I'm considering making the LIA with cheaper, simpler powered components (amplifiers). The problem is that I can't replace the AD630 with a simpler power supply. Sometimes I consider doing a digital LIA directly, but then I would not have any standard to compare.
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Beginners / Re: Automatic golf ball dispenser
« Last post by BTO on Today at 11:59:52 am »Ok guys, the final prototype.Also.. if you want us to have a look at your code, .... Post it
https://youtube.com/shorts/KOmL9WKCEq0?si=T7d2N874ycgET7hB
It would have been nice in their forum if someone could have suggested ways to achieve this.
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Beginners / Re: What size Teflon sleeve tubing are you using for 1/4 - 1/2 Watt Resistors
« Last post by RoGeorge on Today at 11:59:27 am »You mean, like the green isolation in this pic?
Only rarely did that, and usually not with teflon tube, but with isolation leftovers after stripping casual wires.
Only rarely did that, and usually not with teflon tube, but with isolation leftovers after stripping casual wires.
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Beginners / Re: Automatic golf ball dispenser
« Last post by BTO on Today at 11:58:51 am »Ok guys, the final prototype.
https://youtube.com/shorts/KOmL9WKCEq0?si=T7d2N874ycgET7hB
It would have been nice in their forum if someone could have suggested ways to achieve this.
How do you mean ? I mean, You're a newbie so i'll humour this .
But granted that a lot of people didn't respond but those that did did try to help , so.. what did you mean exactly ?
If however you meant that someone should have told you how to do it completely... NO, that's not the way it works.
Mate we derive pleasure from electronics, a large part of that is learning how to do stuff ourselves , therefore i we just said
do this and that and that and this and solder this to that and use this code. You would literally have nothing to do .
We would feel that we deprived you of the pleasure of learning, which is also... the entire point of why i pushed you into the arduino and
ESP32 direction.
so. You are expected to pull your part of the weight as well, (and you did )
Now, you do have an option to ask us to do it all for you, but that would require payment , and that would give you the right to not
care how it's done and to have us just build it for you.
However most people here want to do it for free and to learn, I made the assumption that that's what you were after
so, I'm confused, did you mean that you wanted to be told how to do it all upfront or did you mean you didn't get any support ?
or.. Did you mean that you wanted me to explain how that commentary DF Robot thing works I didn't really understand your comment properly.
so i guess the question is...
WHAT HAVE YOU LEARNED SO FAR
AND WHAT DO YOU WANT EXPLAINED
9
Test Equipment / Re: Standardised Way To Test Oscilloscope Screen Update Rate
« Last post by nctnico on Today at 11:58:48 am »The more I think of it, the less I'm convinced this is actually easy to measure. In the end the rendering engine of an oscilloscope needs to pack multiple acquisitions into a rendered image which is not necessarily equal, but likely synchronised to the screen refresh rate to avoid tearing effects. If you look at the trigger output signalof an oscilloscope, you often see a whole bunch of triggers, dead time and another burst of triggers. The dead time is likely the time needed to create the rendering from (pre-processed) acquired data.No need for a high speed camera though - you have full control of the source signal, so you can create test signals and use a simple single-point optical sensor on a specific area of the screen.High speed camera and frame anlaysis is one way obviously.
If "screen update" means "pixels changed" (assuming a continuously changing input), then I think that's the only way
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Projects, Designs, and Technical Stuff / Re: Control of 2 CAN Open DS402 motors on a single shaft
« Last post by max_torque on Today at 11:58:29 am »Couple of critical questions:
1) is the "perfect" situation that both motors equally share the load at all times and respond identically?
2) How Dynamic is the system. Ie if you applied full torque or full load, what is the maximum rate of change of rotational speed
The answers will dominate what the best control architecture is!
If we assume the answer to 1) is YES (50:50 share is ideal) and the answer to 2) is say 1 second to reach max speed from zero speed
then it's clearly going to be best and easiest to do external speed control, ie to calculate a total torque value, then just split this 50:50 and send out that half torque command to each motor, and you'll need to be able to do this at between 10 and 20 times a second in order to maintain sufficient control bandwidth
There are other options which could be possible but which very much depend on the system dynamics, for example putting both in local speed control mode, but calibrating the PIDs differently to avoid detructive interference (you can have one motor doing all the P and one doing all the I for example)
The other question is what is fundamental oscialtion frequency of the system, ie you say the drives are "elastic", what is the natural frequency of this and will you control system operate above or below it (it really can't operate IN this zone!) Now if the load is varriable, then that no-go control bandwidth zone can be quite wide, so care will be required. For most mechanical systems, it's generally preffered to be above the natural frequency as normally things get "less stiff with time / condition / load" etc
The final question is
"How critical is the speed control accuracy and convergence" Ie, At what point does it actually matter that the speed is "wrong"? If you're making a machine to stir custard, then clearly, you've probably got a lot of tollerance to varriable speed, but a system to drive an elevator full of people, less tollerance. As you know the application, you can make some qualified estimation of the errorband/deadband that your system can tollerate, and this will drive the mechanical and software/controls architecture as appropriate...
1) is the "perfect" situation that both motors equally share the load at all times and respond identically?
2) How Dynamic is the system. Ie if you applied full torque or full load, what is the maximum rate of change of rotational speed
The answers will dominate what the best control architecture is!
If we assume the answer to 1) is YES (50:50 share is ideal) and the answer to 2) is say 1 second to reach max speed from zero speed
then it's clearly going to be best and easiest to do external speed control, ie to calculate a total torque value, then just split this 50:50 and send out that half torque command to each motor, and you'll need to be able to do this at between 10 and 20 times a second in order to maintain sufficient control bandwidth
There are other options which could be possible but which very much depend on the system dynamics, for example putting both in local speed control mode, but calibrating the PIDs differently to avoid detructive interference (you can have one motor doing all the P and one doing all the I for example)
The other question is what is fundamental oscialtion frequency of the system, ie you say the drives are "elastic", what is the natural frequency of this and will you control system operate above or below it (it really can't operate IN this zone!) Now if the load is varriable, then that no-go control bandwidth zone can be quite wide, so care will be required. For most mechanical systems, it's generally preffered to be above the natural frequency as normally things get "less stiff with time / condition / load" etc
The final question is
"How critical is the speed control accuracy and convergence" Ie, At what point does it actually matter that the speed is "wrong"? If you're making a machine to stir custard, then clearly, you've probably got a lot of tollerance to varriable speed, but a system to drive an elevator full of people, less tollerance. As you know the application, you can make some qualified estimation of the errorband/deadband that your system can tollerate, and this will drive the mechanical and software/controls architecture as appropriate...