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  1. Replies
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    Closed: Re: ESD protection for Aruduino Input Pins.

    I agree with Klaus, especially over sharing a common ground and in an automobile application where there can be significant voltage drops between different 'ground' points in the vehicle.

    A better...
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    Closed: Re: [moved] Speaker wattage not known

    You just blew my mental picture of you right out of the water Audioguru: multicolored dreadlocks, punk rocker, leather jacket full of metal studs and in a trance from listening to too much grunge...
  3. Closed: Re: Where to get schematics about SCRs full-wave triggering circuits ?

    A capacitor is a capacitor, electrolytic is just one type of construction. The charge is held across the capacitor, regardless of polarity so it isn't true to say it is only held at the positive...
  4. Closed: Re: Where to get schematics about SCRs full-wave triggering circuits ?

    Following on from post #91:
    158619
    I actually used 22 Ohms in series with the Diac but that is irrelevant for this argument.
    You will notice the same sawtooth waveform, it rises as the capacitor...
  5. Closed: Re: Where to get schematics about SCRs full-wave triggering circuits ?

    I think we are going nowhere fast.
    I can't confirm what your simulator tells you because I don't use Windows and as far as I know Proteus doesn't run in Linux. However, it seems to behave strangely...
  6. Closed: Re: Is it possible to repair this touch Screen FCP Cable?

    VERY hard to repair properly, especially as there is a screw hole next to the damage. It looks as though someone didn't fit the cable properly and the screw went through the cable.

    If I had to...
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    Closed: Re: LT3083 lab PSU question

    Try these tests:

    1. using a high current range, briefly use the meter to short out the +5V to ground. The 7805 should go into current limit at around 1.5A. This will prove whether the input...
  8. Closed: Re: What languages or compiler they use this code

    I'm not sure what is wrong and I'm afraid I can't really afford the time to debug it for you at the moment. The statements are perfectly valid in XC8 though so I would guess it is a configuration...
  9. Closed: Re: Where to get schematics about SCRs full-wave triggering circuits ?

    Racing Klaus.....

    This is a DB3 Diac, 100K resistor and 100nF capacitor:
    158594

    and this is what I see on the scope:
    158595

    Brian.
  10. Closed: Re: Where to get schematics about SCRs full-wave triggering circuits ?

    With 100V and 10K in series it is possible the current through the Diac is sufficient that it doesn't turn off. That's why I wanted you to try 100K as well so you could see how it works. Instead you...
  11. Closed: Re: What languages or compiler they use this code

    The current version of MPLABX is 5.30, I strongly suggest you update as the older versions had lots of bugs (some still present!). That is the IDE though, the program that does the compiling would...
  12. Closed: Re: Where to get schematics about SCRs full-wave triggering circuits ?

    NO! Diacs do not 'clip' the voltage, that's what Zener diodes might do. There is a special characteristic of Diacs that once they start to conduct, the voltage across them drops suddenly and they...
  13. Closed: Re: Where to get schematics about SCRs full-wave triggering circuits ?

    I fear we are going backwards....

    A 100nF capacitor has a reactance (Xc) of 26.5K Ohms. So in your bottom circuit the voltage across the Diac will only reach about 68V peak-to peak even if the...
  14. Closed: Re: How to relieve analog part for digital input?

    Both ways will work but one side of P1/P2 is connected to ground or supply so you not have real isolation.
    In general, it is safer to ground one side of an external connection than have both sides...
  15. Closed: Re: Where to get schematics about SCRs full-wave triggering circuits ?

    One shot and try a slower timebase speed.

    What you should see, if the simulation is working, is a repeating sawtooth waveform. The capacitor charges through the resistor until enough voltage is...
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    Closed: Re: Cw decoder by ik3oil

    I can't see anything obviously wrong but you should keep the wiring as short as possible. The PCB design around the crystal is horrible!

    I think there should be loading capacitors at both ends of...
  17. Closed: Re: Where to get schematics about SCRs full-wave triggering circuits ?

    You are not reading what Klaus explained - it is current that triggers the SCR but it does come from the discharging capacitor.

    Your schematic is correct but the scope settings are not. Switch...
  18. Closed: Re: Where to get schematics about SCRs full-wave triggering circuits ?

    Back to basics eagle1109 - if you charge up a capacitor, it doesn't matter what value or what the voltage is, then short it out, how much current flows out of it?

    Try this simulation: use...
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    Closed: Re: water flow detection in a pipe

    I agree with Klaus, at least tell us if this is a 'one off' to build at home or a mass produced item, it makes a big difference to the solution.

    In general, you could consider acoustic devices,...
  20. Closed: Re: how to select capacitor for ruhmkorff coil?

    If you haven't got an oscilloscope or frequency counter, try using a mobile phone app that measures audio frequencies (there are many!) and let it hear the output of a nearby AM radio. The 'buzz'...
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    [AVR]Closed: Re: Temprature sensors. LM35 vs MCP9700

    Assuming the ADC is 10-bits, with 1.097 vREF the ADC would read 373 with 400mV input.

    Where does the 500 come from in your calculation?

    For reference, I use MCP9701 devices extensively, they...
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    Closed: Re: Cw decoder by ik3oil

    Can you show a picture of the screen please. I am trying to see if the dots are being sent to the LCD by the software or if the dots are caused by a hardware problem.

    Brian.
  23. Closed: Re: Resistance of component bag made of "reddish" ESD plastic?

    Video #7 is quite honestly nonsense. Did anyone notice the comparison between pink plastic and metal flashed bags wasn't done properly? Pink plastic is (I think it's an amide additive) designed to...
  24. Closed: Re: how to select capacitor for ruhmkorff coil?

    Yes, with 50+ years of experience, much of that designing test equipment!

    Brian.
  25. Closed: Re: how to select capacitor for ruhmkorff coil?

    I would argue the opposite. It helps to preserve the contacts although there is some additional loss as the capacitor is shorted out and discharges into the contacts. The coil is essentially a high...
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