Search results

  1. Minder

    Transformers in parallel

    The DC will be around 32v-33v DC after any smoothing caps added. M.
  2. Minder

    12vMM..what does it mean?

    12mm appears to be reference to an off board connection which supplies 100Hz at a 12v level. It monitors the health of the power supply and if the 100Hz is not present resets the watchdog timer. That is the way it seems with a brief scan. M.
  3. Minder

    Need to understand power rating.

    How are you getting generation of AC? what type of motor, the normal motors fitted to a portable application are P.M. DC brushed due to the need for no external excitation needed. The only alternative I could think of is a 3 phase gen with P.M. rotor, but this would be 3 ph? M.
  4. Minder

    Motor wiring help

    Did you locate any capacitor? Are the two windings identical resistance, i.e. swappable? M.
  5. Minder

    Need to understand power rating.

    What is the technology of the AC motor that puts out 12vac? 10HP motor to produce 120w? What are you driving the motor with? at what rpm ? M.
  6. Minder

    Transformers in parallel

    If they are the same part number especially, then it should be no problem. Don't forget to ensure the phasing is correct! M..
  7. Minder

    Capacitors

    Touching just the body is usually no problem, it is placing a hand across the two terminals that you get the zap from, fortunately these terminals are often close together and it is just one hand that gets it. When I was a young apprentice, we used to charge up a large cap using a megger and...
  8. Minder

    Motor wiring help

    He states start and run windings which indicates an induction motor, I doubt it is a shaded pole motor for that application and size, if so there has to be a cap somewhere for the start winding? M.
  9. Minder

    Capacitors

    Depends how large they are (capacitance wise) and what voltage they operate at, usually a short circuit with a jumper is fine, it is when you get the many 1000's of μfd's and high voltage, you may get zapped, Many cases there is a bleed off resistor to discharge them. If you use a screwdriver...
  10. Minder

    Microcontrollers

    I went the Picmicro route, there are many tutorials and projects out there, also you can program in Assembly or C. The Nigel Goodwin Tutorials for a start I see someone has put them all into a .pdf http://www.picvietnam.com/download/Nigel%20tutorial.pdf Also there is a conversion to C for all...
  11. Minder

    electric motor

    +1 on the spin test, but if there is no sound or heat at all from the motor, then it may be a good sign as it would indicate an open circuit before the motor. Look for a thermal fuse or cut out also. What type of grinder is it? With a 1/2hp induction motor it won't be a domestic coffee grinder. M.
  12. Minder

    Simple stall over current 12v dc motor protection?

    You just need a small correctly rated circuit breaker, these do not operate immediately but have a small time delay to allow for inrush. M.
  13. Minder

    Motor wiring help

    The fact the two wires have eyelets fitted indicates they were connected to the terminals, you just need to identify the two windings, and the capacitor, and go from there, in some cases the windings are identical, this makes it very easy for switching between them. Max.
  14. Minder

    Motor wiring help

    If it has start and run windings then it is not a Universal motor. A 1ph induction motor is reversed by swapping the start winding WRT the run winding, which swapping the links achieve. As you can see you supply power to Z1-A2 (or A1 - Z2). This is for uni directional control. And to reverse...
  15. Minder

    electric motor

    Is there a speed control on the unit? Does the motor have brushes?, i.e. Universal motor. If you can open it up easily, then logical trouble shooting dictates checking the voltage from input to motor. It could be something as simple as a broken conductor in the cord. M.
  16. Minder

    RPM sensor for rotating shaft

    Also see the tips'n tricks here. http://ww1.microchip.com/downloads/en/DeviceDoc/01146B.pdf M.
  17. Minder

    RPM sensor for rotating shaft

    These slot sensors go up to around 12mm. http://www.digikey.ca/product-search/en/sensors-transducers/optical-sensors-photointerrupters-slot-type-transistor-output/1967054/page/2?k=slot sensor You can get 30mm style by Banner but they are pricey. M.
  18. Minder

    RPM sensor for rotating shaft

    The light source is built in but if vibrations are too severe a slot opto may not have enough tolerance on the slot, the other option is the retro-reflective sensor as shown in the hand held unit, these have greater range, the down side is degrading or loss of the retroreflective tape or paint...
  19. Minder

    RPM sensor for rotating shaft

    There are photo slot sensors such as the H22A1 or the Honeywell SS40 series of hall effect sensors which require a small magnet on the rotating part. If there is a protruding ferrous metal part such as a fan blade or gear toothed wheel, a ferrous Hall effect detect sensor could be used. There...
  20. Minder

    Ack. Thing I fried something. Noob project help.

    hmmmm.. .High voltage AC to a low voltage (DC?) system?? M.
Top