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  1. Alec_t

    Help with phasors please

    Welcome to EP! This is a Homework Help forum, not a Homework-done-for-you one. Please post your best effort so far at solving this.
  2. Alec_t

    Inverter in vintage mashine(exchanging original part with equivalent)

    Then Kelly's suggestion should work fine.
  3. Alec_t

    How can a magnetic micro usb cable work in both directions?

    ... or it could simply be wired with, say, pins 1 and 5 +ve, and pin 3 -ve.
  4. Alec_t

    Inverter in vintage mashine(exchanging original part with equivalent)

    Worth trying, using any bright light source at one edge. Is the display then clearly readable? If that 'cable' is actually a protective sleeve loosely fitted around a bundle of individually insulated wires then it's unlikely the wires are damaged.
  5. Alec_t

    FM Power

    Everybody's view of what music is "wrong" will be different :rolleyes:.
  6. Alec_t

    Help Identifying MOSFET ?

    Correct. It's wise to allow generous headroom for both voltage and current ratings.
  7. Alec_t

    voltage regulator at 4.3V and 0.7V from 5V input that can handle inputs up to +-12V

    As Kelly suggested :-
  8. Alec_t

    Rapidly change electro magnet polarity.

    What force do they need to exert, at what distance, to qualify as 'reasonable'?
  9. Alec_t

    Dual Speed Control Circuit

    'DB4' identifies a diac.
  10. Alec_t

    Low volume

    Welcome to EP! Without a datasheet we're not likly to be able to offer much help. Check the circuit for any swollen or leaky capacitors.
  11. Alec_t

    Dual Speed Control Circuit

    The blue diode is probably a diac.
  12. Alec_t

    Problem with robot made using arduino

    Yes. For a skid-steer vehicle, the greater its length the greater will be the frictional moment about the turning axis for any given load. Clearly your motors have insufficient power for overcoming the friction involved in skidding the vehicle round.
  13. Alec_t

    Need to drain off curent.

    If the brakes are released and the motors are open-circuit, will the elevator move down under the weight of a full load, or is friction enough to keep it stationary?
  14. Alec_t

    DC Actuator problem

    It's possible there's a bit of wear/play in the mechanism that operates the limit switch.
  15. Alec_t

    Most inexpensive method for detecting if some current is flowing in 120VAC or 240VAC PCB Trace

    That would be dangerous if the thin trace is supposed to be at a safe low voltage. Design rules specify a minimum clearance between traces with a high voltage difference.
  16. Alec_t

    Need to drain off curent.

    Ok. This looks a better bet. The FET does now short the motor intermittently when the elevator moves down, so would give dynamic braking. The body diode is not used here :-
  17. Alec_t

    Need to drain off curent.

    Hmmm, I'm not so sure that will work if the emf generated by the motor exceeds the voltage supply. Also, my bad, it's not equivalent to shorting to get regenerative braking. Back to the drawing board methinks.
  18. Alec_t

    Need to drain off curent.

    Agreed. Something based on the attached circuit should work. A FET is switched on/off rapidly with a PWM signal generator (details not shown). A DPDT switch controls motor direction. During upwards movement of the elevator, the motor current passes alternately through the body diode of the FET...
  19. Alec_t

    Pairing a guitar pedal with new AC/DC adapter

    Agreed. Low-power wall-warts are cheap as chips these days.
  20. Alec_t

    One cell power bank troubleshoot

    .... or the battery is dud/over-discharged and for safety's sake the IC refuses to charge it.
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