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  1. Alec_t

    Trying to repair our VFD

    The component to the left of that IC looks unhealthy, too.
  2. Alec_t

    T-Joint on thin cable connected to Li-Po battery

    If your 'wire' is in fact a double wire going to the + and - of the battery then you will have to be very careful with your blade to avoid shorting the battery.
  3. Alec_t

    Milwaukee Drill RPM Limiting Circuit 0-850 RPM to 0-475 RPM

    If you use a circuit similar to your 'traditional approach' (but with the pot replaced by a suitably-sized fixed resistor) in series with the mains lead to the tool I reckon that should work.
  4. Alec_t

    Trying to repair our VFD

    The blown chip has no heatsink so would normally have been dissipating little power. Its dramatic demise is probably a side-effect of something else drawing excessive current.
  5. Alec_t

    Color Sensor

    Is the LED light always orange, or does the colour change?
  6. Alec_t

    Decoding PWM

    22mS is not enough. The motor would buzz horribly at ~50Hz. From what I see online the typical PWM frequency for a motor of that sort is >1kHz.
  7. Alec_t

    20v 1.7a 3-Pin Din Power Supply

    Assuming the connector datasheet applies to the exact plug you bought then there's a good chance the pinout numbering corresponds to what you have listed. If you get a magnifier and peer closely at the plug you will probably find 1,2,3 moulded into the plastic. It's a pity the PSU_US.jpg isn't a...
  8. Alec_t

    20v 1.7a 3-Pin Din Power Supply

    That's good news. Hope you can trace the power rail connections. Big electrolytic capacitors may be in evidence on the power rails, so the polarity markings on them may give a clue.
  9. Alec_t

    Questions conservation electronic

    A low-power fan-heater?
  10. Alec_t

    Decoding PWM

    Maybe. So why the reference to 0-100% duty cycle PWM?
  11. Alec_t

    Self-Charging Phone Case

    Welcome to EP. A phone has an internal lithium battery which requires an external power source to charge it. Can you post a link to this "self-charging phone case"?
  12. Alec_t

    "Simple" light sensitive, Servo Project

    I've offered a possible solution in another forum.
  13. Alec_t

    Decoding PWM

    If you are trying to control the speed of a powerful motor by PWM then your PWM frequency will need to be much greater than the 50Hz (20mS period) RC signal. Also, you will be increasing the duty cycle range from the present RC 7.5%-12.5% to a 0%-100% range. Those are not trivial tasks. Doing...
  14. Alec_t

    How to make a mains detection unit using an optocoupler

    Years ago I used Externet's post #4 method, except that I used an LDR instead of a phototransistor.
  15. Alec_t

    20v 1.7a 3-Pin Din Power Supply

    I see from the manual that there are MIDI sockets. The centre pin of each MIDI socket (DIN pin 2) is ground, so if you do a continuity check using a multimeter, hopefully you will be able to identify which one of the three pins of the power socket is ground.
  16. Alec_t

    20v 1.7a 3-Pin Din Power Supply

    Have you tried contacting the piano maker directly for any pin-out details? I looked here, but your piano model isn't listed.
  17. Alec_t

    Battery advice for size and weight sensitive project

    Can you test your fan to see if it will run satifactorily on 3.7V (or even less)? Try it with two AA cells, for example.
  18. Alec_t

    can someone please help with this maths calculation for torque?

    Torque here has the units Newton.metres. At 1 metre radius the tangential force would be 0.25 Newtons when the motor is drawing its rated (normal long-term) current.
  19. Alec_t

    20v 1.7a 3-Pin Din Power Supply

    Here's how you would combine two power bricks. One problem, if you don't have the original power supply, will be identifying which pins of your piano socket should receive the +20V, 0V and -20V. This will involve some circuit tracing inside the piano. I'd advise making sure of that before...
  20. Alec_t

    20v 1.7a 3-Pin Din Power Supply

    Sorry, here's the link to a similar one, this time for 20V.
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