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  1. Closed: Re: Radiated susceptibility problem-PWM dimming

    Sorry, I forgot to reply that!

    Source: 400Hz desired signal coming from the dimmer unit: this is a PWM signal given to the lamp.

    Plus: noise: perhaps RF random with a 50Hz powerline modulation....
  2. Closed: Re: Radiated susceptibility problem-PWM dimming

    That is understandable because the capacitor is removing the HF but not bothering the LF. You have (my guess) HF noise modulated by line frequency. That is why I was curious to know the flicker...
  3. Closed: Re: Radiated susceptibility problem-PWM dimming

    Then what? The stray pickup by the long PWM cable? That can perhaps explain 50/60Hz flicker but...

    High impedance at the receiving end? The PWM cable is feeding a high impedance source? Put a 10K...
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    Closed: Re: Best way to shield already fitted cable

    I suspect that somehow some noise is feeding back the PWM generating unit. Bulk of the electronics is there.

    I guess you can measure the flicker freq just by using a photodiode connected to a freq...
  5. Closed: Re: Radiated susceptibility problem-PWM dimming

    I guess that is the likely culprit.
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    Closed: Re: Best way to shield already fitted cable

    So the long cables are carrying the PWM signal to the lamp that is fitted at a distance? I understand now.

    Do you have some idea about the PWM frequency? RF at 80 MHz and/or 300 MHz are not...
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    Closed: Re: How to detect this impulse?

    Are you using a coaxial cable? What is the nominal impedance? Are the impedances (freq bandwidths) nicely matched?

    Perhaps I am not getting the problem right.
  8. Closed: Re: Radiated susceptibility problem-PWM dimming

    I wish I knew! But I can guess.

    The flicker is visible hence the noise is low frequency. I guess it is coming from the opto coupler. Or from the op-amp. Which one? I do not know.

    The flicker is...
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    Closed: Re: Best way to shield already fitted cable

    It is better to tame the noise at the source: please do some digging and try to identify the source of the noise and try to shield it at the source.

    Once you identify the source, you may try to...
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    Closed: Re: How to detect this impulse?

    Your waveform appears to be similar to sawtooth. The fundamental is therefore at 100MHz. But if there is only one pulse, the fourier transformation is a sinc function. For that the fundamental is at...
  11. Closed: Re: Opinions about plagiarized paper on an academic website

    Doing nothing is not an option.

    You need to make sure that the author has not given credit for the extensive "copy-paste"; what is fair is rather subjective.

    First you must contact the...
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    Closed: Re: X-rays on projection CRT

    Cancer can show up only if the cells are rapidly dividing. Most common cancers are of ovaries, prostate, testis, female breast- regions of high cellular activity.

    Skin cancers are less common but...
  13. Closed: Re: Doing electronics on an office carpet (non ESD)

    I beg to differ.

    Hopefully the office is climate controlled. Maintaining the humidity level at a decent level is part of the system. You should run a proper humidifier ALL the time and maintain...
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    Closed: Re: X-rays on projection CRT

    Sad but true.

    It all depends on many factors. In fact too many.

    X-rays are weakly absorbed by the human body. The part that is not absorbed has no effect.

    Most important mode of absorption...
  15. Closed: Re: Doing electronics on an office carpet (non ESD)

    Carpets look glamorous- but electronics business is glamorous too!

    But carpets are really mess. If a component falls on the carpet, it is gone for ever.

    I would have preferred simple PVC...
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    Closed: Re: Most efficient method of smoke extraction

    To remove the smoke, you must remove the air which is the vehicle for the smoke. So it makes sense if you can remove it at the source, before it gets mixed with a large volume of air.

    A suction...
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    Closed: Re: What does 1

    Is TWINT a system variable? Often the system variables are written in ALL CAPS!!

    Take a look at https://www.engineersgarage.com/tutorials/avr-atmega32-twi-registers/

    Perhaps you can understand...
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    Closed: Re: What does 1

    You are right; it does nothing because the contents are not assigned a location. I think the result will be left into the accumulator and discarded.

    You need an assignment statement: x=1<<2; (or...
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    Closed: Re: X-rays on projection CRT

    It is a wise warning and better be safe.

    It does produce a small amount of soft x-rays (you can see that the accelerating voltage is around 25kV and the tube is made of thick glass).

    Although...
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    Closed: Re: question regarding this C operations

    You have added (INCLUDE files) a processor specific header file. Take a look at the inside (do not change anything) and look for a variable TIMER0.

    These system variables are very special: they...
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    Closed: Re: Will a filter block this waveform?

    Well, let me try to understand the other way: it can be more fun sometimes.

    Your base frequency is 40 MHz; let me assume that this is correct but the waveform is not sinusoidal. Then you will have...
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    Closed: Re: Will a filter block this waveform?

    This is DC plus 40 MHz; DC will be fully blocked.

    Your filter has a lower cutoff of 100 MHz; it will block 50 MHz about 3 db. 40 MHz little more.

    You decide whether that is acceptable or not....
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    Closed: Re: question regarding this C operations

    You need to work out in longhand; the time shall be well invested.

    TIMER0 is a register within the processor that has been defined in some header files. The content of this register is described...
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    Closed: Re: question regarding this C operations

    Yes, it can be confusing.

    Simplify!

    Let a -> b |= c;

    The operator |= is similar to += or -= or *= or /=.

    You can write it in longhand:
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    Closed: Re: Bash scripting syntax and TCL

    It is not surprising because the frontends are similar for a reason. The backends are very similar because they use the same system calls.

    Scripting languages are simpler to process compared to...
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