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Type: Posts; User: betwixt

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  1. Closed: Re: Will I be able to drive LED with attached analog circuit ?

    It will work but I would use a bipolar transistor in this circuit. My reasoning is that to use the MOSFET as a switch its gate voltage needs raising more than knee voltage above the source pin. In a...
  2. Closed: Re: 4x4 Keypad for Arduino with color keys and braille texture (no membrane buttons)

    Making your own keypad is fairly easy and you can buy Braille keypad stickers from Amazon and others. You could consider these:...
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    Closed: Re: Halogen Lamp Limit Resistor?

    Look at this link: https://www.electroschematics.com/9730/high-power-led-dimmer/

    It is for high power LEDs but it will work just as well with a Halogen lamp. Note that it runs on DC, you have not...
  4. Closed: Re: Sine PWM calculated with pic, instead of using table

    That seems a far better solution. There is an error in your table at 199 but that may be because of text formatting on Edaboard, I see a gap between 19 and 9.

    Personally, I would also set the PWM...
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    Closed: Re: Bridge Rectifier won't Rectify

    The scope traces look suspicious to me. Given that the scope, probe and stray capacitance is effectively the load after 100M of resistance, I would have expected the opposite to have happened, the...
  6. Closed: Re: Sine PWM calculated with pic, instead of using table

    Remember that you can't produce two different PWM signals simultaneously with only one PWM generator but if one of the signals is the inverse of the other you can use a logic inverter to produce it....
  7. Closed: Re: Sine PWM calculated with pic, instead of using table

    I think it will work but the waveform will be quite distorted. I do not use BASIC at all but I would guess the PULSOUT command uses a software loop to create the delay. It is unlikely the delay will...
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    Closed: Re: Active HF phase shifter?

    The phase shift in your original post depends on the reactance of the capacitor so it varies with frequency. If you manage to find suitable values it will still need 'tuning' to each frequency to...
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    Closed: Re: Bridge Rectifier won't Rectify

    Are you compensating the probe alone or with the HV divider resistors attached? You need to apply the square wave through the divider then do the compensation. I suspect you have inadvertently added...
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    Closed: Re: Bridge Rectifier won't Rectify

    What exactly is driving them, the waveform suggests it is a single pulse and the transformer is 'ringing'.
    Are the tabs mounted on a a heatsink? I appreciate they are insulated but the accumulated...
  11. Closed: Re: NodeMCU sinking current through DIO while power is off

    The voltage ratings and polarity limitations are from the DIO pins (and others) to the ground pin. Ask yourself what voltage will there be between DIO pins and ground if you connect the negative side...
  12. Closed: Re: NodeMCU sinking current through DIO while power is off

    I'm hardly surprised, disconnecting the ground will almost certainly violate the maximum voltage and polarity ratings of the nodeMCU.
    Consider that the DIO pin effectively becomes the ground...
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    Closed: Re: damaged remote control

    Cleaning the board AND the keypad mat is needed. I doubt the electronics is damaged.
    Take the floppy plastic keypad mat and wash it in warm (not hot) water with detergent, then rinse it and leave it...
  14. Closed: Re: Problem with Logitech Audio PCB (No Sound Output)

    It might but it won't work as well and you risk it being damaged or even exploding. You can generally increase the value and working voltages but you should never reduce them.
    If that part was...
  15. Closed: Re: Why does my homemade Yagi wifi antenna perform so poorly?

    Where is the folded dipole?
    The ends of the feeder cable need tidying up (they are part of the dipole) but they should go to the ends of the folded loop.
    Folding the dipole reduces its impedance...
  16. Closed: Re: interfacing IR remote using NEC protocol - mikroc for PIC

    Wow! That's a fast PIC!

    I think hexreader was referring to the PIC clock frequency not your PC.

    Brian.
  17. Closed: Re: circuit design help analog to Potentiometer

    From the schematic it looks like you don't need a potentiometer at all, just a variable voltage.

    The "CVS MAX TRIM" and "CVI MIN TRIM" circuits just set the voltages at the ends of R1 to restrict...
  18. Closed: Re: Problem with Logitech Audio PCB (No Sound Output)

    The top picture looks correct to me, assuming the number refer to the actual pin numbers on the IC.
    Be aware that reversing the IC will probably kill it, even if it doesn't get hot.

    However, just...
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    Closed: Re: Reset problem in ds pic33ep512mu810

    The problem is clearly in line 234, near the function for grinding smoke.

    If you want a sensible answer you will have to give us more information, we have absolutely no idea of your hardware...
  20. Closed: Re: To set two WiFi module(Esp8266) one as sender and other as reciever.

    Search for "ESP8266 modem" for clues.

    Brian.
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    Closed: Re: Embedded Linux Application

    ANY application can use embedded Linux, not just the ones you mentioned. It is popular because it is free and open source, that means you can modify it for your specific needs.
    Understand that...
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    [ARM]Closed: Re: stm32 interfacing with enc28j60

    As far as I know the enc28j60 just compares whatever IP you tell it with the data stream. I don't think it is aware of what the numbers actually mean or have any understanding of classes.

    Brian.
  23. Closed: Re: Keypad playing sounds - Recommendation for design

    I agree with Barry, you need to give us a little more information.

    How many keys do you need, to some extent that decides the kind of keypad you need?
    Are the sounds complex (like...
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    Closed: Re: controller not wark proper in power on

    Maybe not a good idea to share the same crystal between two ICs, try disconnecting the OSC output from U6 or you have two conflicting outputs connected together. Ideally, use two crystals.

    What...
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    Closed: Re: Active HF phase shifter?

    It will work but the limitations of the components, particularly the potentiometer will seriously degrade it as the frequency increases. The principle is to use the first and second stages as phase...
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