Search:

Type: Posts; User: KlausST

Page 1 of 20 1 2 3 4

Search: Search took 0.08 seconds.

  1. Closed: Re: Battery cutoff voltage vs 0% battery voltage

    Hi,


    What advice do you expect?

    Cutoff voltage depends on battery, not on application.
    For sure you may measure the battery voltage...but it gives not much information about health and charge...
  2. Replies
    12
    Views
    219

    Closed: Re: Wiring of DC fans in Series

    Hi

    Try this:
    * NPN, PNP, 2x R = 4k7

    Wire it this way:
    * 30V --> NPN_C
    * NPN_E to PNP_E = 15V output
    * PNP_C to GND
    * resistors in series, one end to 30V, the other end to GND.
  3. Closed: Re: Holding button for 2s to trigger 555 timer

    Hi,

    On button press: the capacitor gets slowly discharged by a high ohmic resistor
    On button released: the capacitor fastly gets discharged via a diode

    Klaus
  4. Replies
    32
    Views
    1,348

    Closed: Re: 12 Bit ADC with interfacing SPI in STM32

    Hi,

    read my previous posts

    that's the wrong way round

    Klaus
  5. Replies
    2
    Views
    81

    Closed: Re: At45db041b vs at45d041

    Hi,

    If I need to know that, I'd compare the datasheets.

    I'd focus on voltage levels, timing...

    Klaus
  6. Replies
    1
    Views
    72

    Closed: Re: L293d - Input Voltage (motor operation)

    Hi,


    You should not guess, better read the datasheet.
    It clearly says every input voltage above 2.3V is valid HIGH level.

    Better than long textual description is a picture.
    --> please show...
  7. Replies
    12
    Views
    219

    Closed: Re: Wiring of DC fans in Series

    Hi,

    A power voltage divider could be made with two equal resistors, an NPN and a PNP...
    Not very precise, but good enough for fans

    Klaus
  8. Replies
    32
    Views
    1,348

    Closed: Re: 12 Bit ADC with interfacing SPI in STM32

    Hi,

    Your scope picture (especially the upper one of post#29) is awful. Don't you recognize that the sampling rate is much too low for your signals. The SCK looks far away from being a square wave....
  9. Closed: Re: Generation of 4 Phase Shifted clock Signals

    Hi,

    From your first post I thought about sinusoidal waveform with positive and negative voltage swing.

    Now it seems to be a squarewave...
    with unknown voltage swing.
    Unknown risetime and...
  10. Replies
    9
    Views
    264

    Closed: Re: USB to RS232 exactly similar to COM1

    Hi,

    draw a sketch.

    Klaus
  11. Closed: Re: Battery cutoff voltage vs 0% battery voltage

    Hi,

    it (solely) depends on the battery.
    Read the battery datasheet or contact the manufacturer.

    Also visit www.batteryuniversity.com

    Klaus
  12. Replies
    5
    Views
    191

    Closed: Re: Using AD831 in parallel

    Hi,


    I doubt the PCB is getting hot. Usually the electronic parts getting hot. .. and only some of them.

    To detect which one is getting hot:
    * power off and let all get down to room...
  13. Replies
    9
    Views
    264

    Closed: Re: USB to RS232 exactly similar to COM1

    Hi,


    No.
    It just says it works with your computer, but it does not say anything about compliance.
    *****
    True: RS232 idle state = high = 1 = negative voltage (lower than -5V)
    *****
    ...It...
  14. Replies
    5
    Views
    191

    Closed: Re: Using AD831 in parallel

    Hi,

    First you need to determine:
    * How much current can your supply deliver
    * How much current do you expect your circuit to draw
    * Measure how much your circuit really draws

    We don't know...
  15. Replies
    3
    Views
    154

    Closed: Re: Maintaining supply voltage on load

    Hi,

    There is no GND plane? Is it?
    (Maybe you used copper pour --> this is not compareable to a GND plane)

    If not: good luck.
    Especially with your switching power application.
    Did you test:...
  16. Replies
    5
    Views
    191

    Closed: Re: Using AD831 in parallel

    Hi,

    * bad DVM
    * bad -5V power supply
    * too high current

    Klaus
  17. Replies
    32
    Views
    1,348

    Closed: Re: 12 Bit ADC with interfacing SPI in STM32

    Hi,

    1k seems to be OK.

    But in detail it depends in:
    * expected speed
    * drive strength of the output pin
    * signal trace length, connected devices (= capacitance)

    The good thing is:
  18. Replies
    6
    Views
    184

    Closed: Re: average value of as square wave

    Hi,

    What "design procedure" ? ...for two parts: R, C.

    R C low pass filters are explained million times in the internet, since it's probably the most used circuit.

    Klaus
  19. Replies
    6
    Views
    184

    Closed: Re: average value of as square wave

    Hi,

    A low pass filter?

    Klaus
  20. Closed: Re: How to calculate transformer winding losses

    Hi,

    To be honest: I donīt know the answer.

    * maybe the copper loss is tested with DC. Then there are additional losses caused by AC: Proximity effect and skin effect.

    ***
    About leakage...
  21. Replies
    9
    Views
    264

    Closed: Re: USB to RS232 exactly similar to COM1

    Hi,

    Read RS232 specifications.
    There is no need for 11V. If Im not mistaken, then even 3V / -3V levels comply with RS232.

    If your connected hardware does not work with levels below 11V, then...
  22. Replies
    6
    Views
    188

    Closed: Re: power supply residual voltage

    Hi,


    I donīt think this is possible.
    Most probably the power has a a capacitor at the ouput.
    It needs a lot of power to charge this capacitor to +/-12v within 10us.

    And negative voltages...
  23. Replies
    2
    Views
    91

    Closed: Re: ADC input with low pass RC filter

    Hi,

    We donīt know about your circuit.
    We donīt know what kind of ADC you try to build.
    We donīt know what cutoff frequency you like to have.


    No.
    If you solve the above equation with...
  24. Closed: Re: Desperate for help (computer fan control) or this could cost huge $$$

    Hi,


    Did you read the WIKIPEDA article.

    It says it delivers 2 pulses per revolution.
    That's all you need.
    Measure/calculate the count of pulses per minute and divide it by 2 ... and you are...
  25. Closed: Re: Regulator strategy - embedded system power design

    Hi,

    Simple answer: There is no simple answer for your question.
    The only thing that is very likely: the less voltage you give to the MCU, the less power it will draw. Thus - just from the view of...
Results 1 to 25 of 500
Page 1 of 20 1 2 3 4