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  1. Minder

    HAM Radio Relevance Currently and Personal Reflections.

    I recall when I served with the Royal Signals and posted to Libya, we had a ham shack set up that any of us could key out on. There was only one other ham radio registered in Libya at that time, (50's). Consequently whoever was operating that night was swamped, clamoring for our QSL card...
  2. Minder

    Type of single phase AC motor?

    If you want to detect if it is a PM motor, short the motor terminals or leads and try to spin the rotor, if PM, a resistance to turning will be felt when trying to spin. If it is PM, it will be a form of ECM (electronically commutated motor).
  3. Minder

    DC motor hookup for reuse ( recycle)

    Appears to be Fischer-Paykel style outrunner motors . Similar to used in washing machines. They will generate 3phase AC, If DC required will need a 3ph rectifier. ,
  4. Minder

    Controlling AC contactor by NC & NO push button

    Normally on a 3ph contactor there is a smaller aux contact for the coil latching circuit and normally only switches the coil current.
  5. Minder

    Controlling AC contactor by NC & NO push button

    In Fig A , a N.O. contact on the relay would be wired across the N.O. momentary start PB, this contact would then act as a retaining contact when the contactor is picked up. It is used primarily in E-Stop -Safety circuits where multiple N.C. Stop PB are often used in the series string.
  6. Minder

    Need help sourcing a power transformer

    That is why I mentioned 'Custom' IOW they will build to your spec. ! In any case, a Toroidal type is very easy to modify/customize with a simple overwind.
  7. Minder

    Need help sourcing a power transformer

    There is a Co. Antek that makes nice custom toroidal versions.
  8. Minder

    VFD auto restart after load disconnect

    Disconnecting the VFD defeats the object of the soft start. The input to a VFD is a 3ph bridge rect followed by very large bank of capacitors, at switch on these are a high load across the supply, defeating any ramp-up setting in the VFD. .
  9. Minder

    Convert 1 phase to 3 phase by using an old washing machine

    What frequency is the supply, the motor says 17000 RPM??
  10. Minder

    Induction motor short circuit

    If you have the motor off, place it on something insulated, remove the earth GND conductor and see if it runs OK, if it does, test voltage from frame to earth GND. If it runs up to speed, place the earth to the motor frame and see if it trips when up to speed.
  11. Minder

    Induction motor short circuit

    You have to use a 'Megger' instrument to test the insulation. An ordinary meter does not always show leakage, it does not take much to affect a GFI breaker.
  12. Minder

    Convert 1 phase to 3 phase by using an old washing machine

    The latest machines have used the Fischer-Paykel motor for some time now, they are 3ph out-runner motors, i.e., the rotor is external to the motor similar to the 3ph RC motor construction. Also they are direct drive, no gear box.
  13. Minder

    Minimizing 120VAC relay EMI

    I use 1N400x versions, the 1n4007 covers up to 1kv.
  14. Minder

    Issues with PIC16F1503

    No UART posted in a few forums and has been answered.
  15. Minder

    Can't find the transformer I need so need to build my own

    SMAW Arc welding transformers cannot maintain the voltage when high current flows, they are designed with high voltage output in order to strike the arc, as soon as the arc is struck and current flows, the voltage collapses but high current remains. The have an adjustable shunt in order to...
  16. Minder

    Craftsman 18V Ni/Cd Circular Saw with DC Motor Problem - HELP !

    Just a heads up in case you found it the cause!
  17. Minder

    Simple Circuit to test TT Slotted optical switches

    Simply supply a resistor in series with the input diode rated under the spec sheet maximum. and dependant on the test voltage used. On the output, use a 5k to 10k resistor to common (GND) from the output emitter, connect collector to a +ve From the emitter connect to the gate of a 2N7000 ...
  18. Minder

    Craftsman 18V Ni/Cd Circular Saw with DC Motor Problem - HELP !

    It looks like a very common motor that is available from a few places, Amazon included. Advertised as small power tool motors.
  19. Minder

    Craftsman 18V Ni/Cd Circular Saw with DC Motor Problem - HELP !

    Generally high voltage = higher current, also voltage determines RPM.
  20. Minder

    Craftsman 18V Ni/Cd Circular Saw with DC Motor Problem - HELP !

    You may have a bad, (short in the armature) winding, the only/best way to confirm this is with an armature tester called a Growler.
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