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Type: Posts; User: KlausST

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  1. Replies
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    Closed: Re: Hfe of NPN at extremely low base current

    Hi,

    Before we talked about V_ce of the first bjt (to safely switch OFF the second bjt), now you talk about the V_ce of the second bjt.

    We have no information about the second bjt's collector...
  2. Closed: Re: Circuit to pulse from 1v to 1.1v repeatedly.

    Hi,

    Why no Mosfet?

    Klaus
  3. Replies
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    158

    Closed: Re: Reliable GPS and Compass sensors

    Hi,

    Another post asking for a "best" device....

    Ask 10 designers for the "best" part and get 10 different answers.

    Klaus
  4. Replies
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    Closed: Re: Linear led current regulator

    Hi,


    ...and where are your requirements?
    Voltage, LED current range, input signal type and range, precision, settling time...

    Klaus
  5. Replies
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    Closed: Re: Hfe of NPN at extremely low base current

    Hi,

    Without additional information I see no reason why not to decrease R215 .. maybe increase C214 to get the desired timing.
    It should improve performance.

    You could also replace one or two...
  6. Closed: Re: What is the difference between IRF510 and IRF510N?

    Hi,

    You buy a "unbranded" electronic device, made in china, from an unreliable source, without datasheet.
    So what do you expect from us?
    All we can do is give "equal unreliable" informations. ...
  7. Replies
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    Closed: Re: Multiple relay with controllers

    Hi,


    No, just to minimize the count of modifications to the given schematic...

    There are so many ways and so many reliable and proven circuits available ... the OP could use.

    Klaus
  8. Replies
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    Closed: Re: Hand soldering a 6x6mm QFN (28pin)

    Hi,

    Don't stress.
    This is not a "very" diffucult to solder device.

    I even don't see the need for extra flux, since a good solder (wire as well as paste) schould already contain it.
    I've hand...
  9. Replies
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    Closed: Re: Multiple relay with controllers

    Hi,

    ...or use a HCT595...

    Klaus
  10. Replies
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    947

    Closed: Re: Multiple relay with controllers

    Hi,


    It does not work ... how can it be correct?

    Klaus
  11. Closed: Re: SVPWM crooked 3-phase inverter output. What is wrong with the circuit ?[PROTEUS]

    Hi,

    Without the information what the scope pictures show, they are about useless.
    Where dud you connect "input" and "output"?

    If possible show all scope pictures with the same timing...
  12. Replies
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    Closed: Re: Multiple relay with controllers

    Hi,

    A standard procedure for debugging circuits:

    * Measure the HIGH and LOW voltage levels at the HC595 inputs...
    * cross check with datasheet whether they comply with the specifications.
    ...
  13. Closed: Re: 74HC4060 Oscillator/Counter Frequeny Problem

    Hi,

    Show a photo of your circuit, where we can see all your connections.

    There are many manufacturers that produce HC4060. Please tell us the exact part name and manufacturer.
    It would be very...
  14. Replies
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    Closed: Re: ELECTRICAL AND ELECTRONICS Instrumentation

    Hi,


    RMS+RMS = RMS is only true for signals of same waveform, same frequency and sane phase.

    Now you ask: "Why all the extra squaring/square-rooting?"
    (I'm really not sure if you mean this...
  15. Replies
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    223

    Closed: Re: Hfe of NPN at extremely low base current

    Hi,

    To the circuit.
    I think it should work.

    Some ideas that come into my mind:
    * the current through the zener is much lower than specified --> Expect a much lower zener voltage.
    * maybe a...
  16. Replies
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    Closed: Re: Hfe of NPN at extremely low base current

    Hi,

    50uA base current isn't extremely low.

    And the datasheet tells a lot of low curents:
    Look at
    "ON CHARACTERISTICS" -> "DC current gain"
    Here they use 10uA of I_C (collector current) .......
  17. Closed: Re: Two-tone simulation of power amplifier design

    Hi,

    Spacing?
    I don't know what you want to achieve, but in case you want some IMD simulation, both frequencies need to be at the same time.

    Klaus
  18. Closed: Re: Identify capacitor with marking code L62 104

    Hi,

    OK, why not think the other way round?
    You say the capacitor is defective ... then maybe it wa not the best suited capacitor for this application.

    --> find out the Mosfet_driver_partname,...
  19. Replies
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    Closed: Re: Hand soldering a 6x6mm QFN (28pin)

    Hi,

    It seems on your PCB the center pad is not connected to GND..

    I don't think using loads of solder paste is a good idea.
    Maybe use the syringe to apply the oaste and a blade (scalpel) under...
  20. Replies
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    190

    Closed: Re: PGA Vs VGA and Their Sensing Approach

    Hi,

    Please be more specific, give examples.

    Klaus
  21. Replies
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    Closed: Re: PGA Vs VGA and Their Sensing Approach

    Hi,

    Documents may use the abbreviations in different ways....

    Did you read the datasheet(s)?
    * If NO, then do this first.
    * If YES, then please give us the (link to the) datasheets and tell...
  22. Closed: Re: Identify capacitor with marking code L62 104

    Hi,

    Of course. 100n.

    10 x 10^4 = 100,000 pF.

    Maybe it's a bit late today for me.

    Klaus
  23. Replies
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    Closed: Re: NodeMCU ESP-32S pitch

    Hi,

    There are datasheets... telling you the measures.

    Klaus
  24. Closed: Re: Identify capacitor with marking code L62 104

    Hi,

    I agree with: "104 means 10,000 pF" = 10 x 10^4 pF (can be found million times in the internet)

    But it's 10nF then...

    Klaus
  25. Replies
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    Closed: Re: Stable PWM during Voltage Loss

    Hi,

    I'm confused, too.
    I also don't understand, why an FPGA comes into play...and boot time of it, and where the 5A are...

    From post #1:

    ...for this a 100uF capacitor should be well...
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