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  1. Minder

    One Way Communication from Chip-to-Chip

    I didn't see any offer as such so far? M.
  2. Minder

    What component??

    Iv'e seen spark gap suppressors identical to that especially on older equipment. M.
  3. Minder

    What component??

    Try measuring it, both directions. It could be anything from a vacuum arc suppressor to a semiconductor HV diode. M.
  4. Minder

    12V 200A Synchronous PWM DC Motor Controller

    Is it PM field or wound field? Older and larger automotive starter motors are series/wound field and operate in a runaway condition and require a load at all times. M.
  5. Minder

    DC motors and speed control

    Not really a good idea to switch the motor leads, if the speed pot is not the zero-first kind, then it is possible to but full power across the motor causing excess current. If the brushes are at 90° you can reverse it, most TM motors specify CW or CCW because of a threaded flywheel, Not...
  6. Minder

    Shielding a Linear Heathkit Power Supply

    CRT's typically had Mu-metal sleeve over the tube for shielding. M.
  7. Minder

    12V 200A Synchronous PWM DC Motor Controller

    Do you mean build (configure) a 200amp PWM controller, what is the nature of the motor, 3ph synchronous or DC brushed or BLDC? M.
  8. Minder

    Resonance Frequency

    I go along with post #3. M.
  9. Minder

    Resonance Frequency

    What I got from the OP is the resonant freq required only? M.
  10. Minder

    Resonance Frequency

    I agree, Rs and L + Rc and C appear representative of two single circuit components. Rs and Rc would affect the Q. M.
  11. Minder

    DC motors and speed control

    Is it the MC-60M controller mentioned in the pic? If so I have a reverse engineered print of it, it not PWM output however but SCR bridge. M.
  12. Minder

    DC motors and speed control

    The other thing you need to know is the speed input, some are via PWM, some you can use a 5k-10k pot (analogue) for speed control. Others have a control input that requires that you take the control to zero first before acceleration. Is there a number on the motor control board? You would...
  13. Minder

    DC motors and speed control

    The first one is lower torque/current so it should be fine to use on the controller, most TM controllers are PWM and give fairly smooth operation down to low rpm. You need to remove the flywheel on the motor if you haven't already. They are both pretty close in amperage so either should work OK...
  14. Minder

    AC Diode

    More detail on the type of ind lights, you show them wired in series? Are the lights at the Pump or close to the source? M.
  15. Minder

    AC Diode

    Again reading between the lines, I am assuming the intended circuit is the RH one, and the LH is just there to show a non acceptable version, not all that clear!!?? Also seems bad practice to use lamps in series with a pump?? Seems like a basic design flaw. M.
  16. Minder

    AC Diode

    It seems to me the OP is asking how to power a device from two possible sources, and asks about the common method of using blocking or steering diodes to achieve it? As shown in his Dwg. M.
  17. Minder

    Transistor switching on another voltage supply

    Set a LM311 to switch over at 1v operate into a 4n25 (25¢), if you need to condition the output for a little more power a 2n7000 will do it up to 200ma. Total ~ $1.00 Max.
  18. Minder

    Recycling an old phone/fax machine any ideas?

    Stepper motor, traction mechanism? M.
  19. Minder

    Turntable Spinning Fast in Reverse

    An ECM motor or VFD, or Fisher-Paykel outrunner motor all require the AC to be converted to DC to supply the electronic commutation circuit in order to produce the the 3phase for the stators. It would be interesting to see the other side of the P.C. board on the motor, where 6 leads enter the...
  20. Minder

    Turntable Spinning Fast in Reverse

    Just about all motors have a rotor and a stator, in the case of electronically commutated as in PC (two wire) fans and some of the small 2 wire motors on ebay, they have a PM rotor and an electronically commutated stator and have internal electronics for PWM control. A DC or BLDC motor, without...
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