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  1. crutschow

    MOSFET not giving sufficient power

    So does the Arduino put out 5V or 3.3V? Yes, you may need a different MOSFET as bertus suggested.
  2. crutschow

    MOSFET not giving sufficient power

    It appears the Vcc is not connected on the module, only signal and ground.
  3. crutschow

    MOSFET not giving sufficient power

    The IRF520 requires a Vgs of 10V to fully turn on (below). What is the control signal level you are applying?
  4. crutschow

    Propeller audio interface for audio quality?

    To me "warmer" means it doesn't have as much high frequency response, so would be lower fidelity. Some like the sound of vinyl records and tube amps saying they sound "warmer", but to me, that's just due to a reduction in fidelity. But it's whatever sounds better to you that's the best criteria...
  5. crutschow

    Low power bistable latch arrangement

    If you post a circuit diagram of what you have, we could likely be of more help.
  6. crutschow

    Low power bistable latch arrangement

    If you had that, how would you differentiate between opening and closing triggers?
  7. crutschow

    Is this possible to do?

    That's a good idea. The LED will light when the phone is off-hook, and it will take no power when the phone is on-hook. You could use a smaller LED (such as 20mA rated) in parallel with a resistor (say 100Ω) to keep the LED current below its rating.
  8. crutschow

    How do I connect the pull-up resistor to pin 7 of the LM555 timer?

    Pin 7 is the discharge transistor for the timing capacitor. What are you adding a resistor, which makes little sense? Post a schematic.
  9. crutschow

    How to decide input filter specifications for linear power supply design

    And what are your requirements for this "precision" supply? Does it have a regulator?
  10. crutschow

    Is this possible to do?

    Depends upon what connections are available to the tri-color LED. Likely, using a Zener, you could get one to light dimly when off-hook and two to light simultaneously when on-hook. Look up its part number. Otherwise, apply a voltage in series with a 10kΩ resistor in the reverse direction and...
  11. crutschow

    Is this possible to do?

    If you put a 10v to 20V Zener diode in series with the LED, it should turn off completely off when the phone is off-hook.
  12. crutschow

    Is this possible to do?

    Just reverse the meter leads to get a positive reading. How did you differentiate the line connection polarity? Now you can try connecting a LED with a resistor in series across the line when on-hook to see how much it drops the voltage (you likely don't want the voltage to drop to less than...
  13. crutschow

    Will MOSFET be Replaced in the Future?

    How is that related to the OP's question? :confused:
  14. crutschow

    Is this possible to do?

    Yes. You don't need a call coming in, just pick up the phone (off-hook) and measure the line voltage. The current would need to be small, since the phone system (MagicJack in this case) detects the 48V current to determine if the phone if off hook, indicating you want to make a call.
  15. crutschow

    Is this possible to do?

    I can help you with that if you can measure the MagicJack on-hook and off-hook voltages.
  16. crutschow

    Is this possible to do?

    Do you mean you are giving up on the project? The MagicJack phone output is meant to emulate the POTS signal levels of 48Vdc on-hook and about 7-12Vdc off-hook (with a 15-20mA telephone load), but I don't know how close. That's why I suggested a measurement of those voltages. But I see no...
  17. crutschow

    Is this possible to do?

    I would measure the on-hook and off-hook voltages of your system to see if the circuit is compatible with your MagicJack voltages.
  18. crutschow

    class A push - pull amplifier ?

    Push-pull is not Class A, it is Class AB or B.
  19. crutschow

    2 mosfets switch

    How are the MOSFETs connected to their loads?
  20. crutschow

    routing 2 channel audio to 5.1 speaker system

    I'm confused. Obviously if you tie the two outputs directly together you will have no stereo separation. I'm referring to connecting the two (line level) stereo outputs together through two equal value resistors (e.g. 10kΩ) for the subwoofer input. That should have no significant effect on the...
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