Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

Search results for query: *

  1. Mobius44

    CE Compliance for an OEM

    Paul, The CE Mark is self-certified, but I suggest you use a third party to guide you through the process the first time. The big names like UL, CSA, or TUV can help you, but if cost matters then I recommend using a smaller consultant. The company I work for recently used Technology...
  2. Mobius44

    high voltage micro motor

    Gas powered helicopters are already available and could provide the extended flight time you want. They might be more difficult to fly than the multi-rotor design, but that's an easy problem to solve with a little practice. I'm sure you can figure out how to add a larger gas tank and camera...
  3. Mobius44

    Blinking Lights

    That's unfortunate, but since the hard start didn't help you then try to locate and attempt to reduce the voltage drop occurring during the compressor start. Since you've checked for loose connections and found nothing, perhaps instead the wiring is undersized, nicked, or corroded? The voltage...
  4. Mobius44

    What geared dc motor is best to use for a custom automotive exhaust.

    A few inches of cabling or linkage between the motor and damper should do wonders for keeping the motor cool and allow some flexibility in the end users selection of mounting location, but if you must mount the motor directly on the exhaust piping try using a heat shield combined with...
  5. Mobius44

    Blinking Lights

    Keep in mind the start capacitance isn't being used to directly provide the ~100 extra starting amps, rather it only affects the start winding current phase angle with respect to the run winding current phase angle. Thus although the start capacitance is small, it has a large effect on how...
  6. Mobius44

    Blinking Lights

    Loose connections commonly cause this issue, but since you've checked that out then you might try using capacitance to reduce the starting VAR surge. However you don't want the capacitance at the service entrance, rather you want it at the compressor, and only while it starts. Have you tried...
  7. Mobius44

    Which VFD to avoid GFCI tripping?

    It seems to me Lucas compares the 1600 Euro 0.37kW NFO VFD to a 160 Euro 0.37kW conventional VFD, not the cost differences of the 0.37kW and 15kW NFO VFD's. Thus the pricing Lucas obtained for NFO appears to be about 10x higher than conventional VFD's. This could help explain why NFO drives...
  8. Mobius44

    Which VFD to avoid GFCI tripping?

    Lucas- As JRaef notes GFCI for ground fault protection are normally only found in wet environments (bathrooms, kitchens, outside, etc.), and not all over the home. Perhaps you're thinking of AFCI for arc fault protection? They have much broader use, but shouldn't interfere with a VFD. Gunnar-...
  9. Mobius44

    Crimp terminal reeling service?

    Sorry, but I don't know of anyone that has a process to put loose screw machine parts on a reel. However I've seen other machines that used a vibratory bowl feeder for such parts, perhaps that approach could work for you? You also might try redesigning the terminal from a reel of stamped metal...
  10. Mobius44

    Why do timers that do not requie neutral have minimum load current

    The 2-wire timer "leaks" a small current into the load rather than using a neutral. The load current needs to be much larger than this leakage current to ensure the leakage current has neglible effect on the load, and that's why I think the minimum load current rating's higher for a 2-wire...
  11. Mobius44

    thermal massflowmeters for compressed air

    You'll have to put the thermal mass flowmeters somewhere without condensed water, because that throws off the flowmeters thermal sensing of the airflow. Since you don't have adequate drying capacity, you could try the suppliers suggestion to pipe them upstream and hope it's hot enough to...
  12. Mobius44

    thermal massflowmeters for compressed air

    While changes in humidity might not have much effect, condensed water droplets in the air stream could throw off the meters as they impact the thermal element. Can you move the meter downstream of a drier or coalescing filter?
  13. Mobius44

    How do you calculate weight from current?

    Surely you can find physics equation for power required to lift a mass over a certain time. Make the lifting power equal to the electrical power, and you can find how mass and current are related. If you want to get more accurate figure in the losses between electrical power consumed and...
  14. Mobius44

    Convert Alternating DC to AC

    It requires an external power source, but you could wire an adjustable DC power supply with isolated output in series with the signal to cancel the DC component, leaving only the AC component. The DC power supply needs current output rating of at least 10A and voltage output rated for...
  15. Mobius44

    Contactor pole frequency limits

    I'm glad your supplier was able to help. While the different supplier's factors are very similar, it's always good to have "official" numbers. For reference the Rockwell information google found is linked here: http://tinyurl.com/6zmfa6d and the Rockwell derating table is found here...
  16. Mobius44

    Contactor pole frequency limits

    It's a very interesting question, but I think it can only be answered by your specific contactor supplier. Google found me some information from Rockwell showing derating multipliers ranging from 0.7 to 0.3 for various contactors switching 1kHz load. Since you're not switching under load I...
  17. Mobius44

    Block diagram programming for noobs

    Search engines like Google are very useful, I found this example of Simulink programming for PIC: http://tinyurl.com/2bl32pf Of course a PLC is different than a PIC, but I'll let you google that yourself. I think you'll find most PLC programmers just use the software provided by the PLC...
  18. Mobius44

    Soft starts on 200 Hp Motors

    1) If the wires are adaquate for across the line start they will be fine for soft start. 2) Similar ampacity can be obtained from 2-350kcmil copper cable, but it probably can't fit your 500 kcmil lugs either. It throws a red flag that the soft starter may be undersized if it can't handle the...
  19. Mobius44

    mechanical turn signal blinker.

    I think the "how it works" explanation is accurate, the one I found shows a picture of a blinker's internals. There isn't any magic going on, it's just a heater and bimetallic strip. http://auto.howstuffworks.com/turn-signal2.htm
  20. Mobius44

    Controlling 110/120V with a 3V signal? Possible?

    If you're trying to remotely and inexpensively control a 120VAC outlet you might consider using existing products similar to this "remote control switch socket": http://tinyurl.com/3ybns3w
Back
Top