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Recent content by Steventyj

  1. Steventyj

    Depth of water sensing

    I like the motor monitoring idea, however here is a different, unrealistic idea: Heat the air above the column of water in the well. Put a thermistor in the bottom of the well and in the output water at the top of the well. Calculate the temperature difference and from that determine how long...
  2. Steventyj

    Why a sine wave output of a voltage regulator?

    Alright I geuss I will have to start reading those more carefully. Thanks for the help guys, im in the lab now and its working.
  3. Steventyj

    Why a sine wave output of a voltage regulator?

    Thanks for the advice guys. Although cbarn your comment about reading the datasheet was a bit of an assumption. http://www.national.com/ds/LM/LM7512C.pdf states that no external components are required.
  4. Steventyj

    Developing a robotic app

    Are you going to need to be able to provide holding torque or will this thing be in constant motion with a predictable rest state when it is turned off? It may be worth looking into motors with electric brakes, this may also be a safety issue - eg power outage doesn't cause the creation to hit...
  5. Steventyj

    Why a sine wave output of a voltage regulator?

    I was in the lab today working on a circuit and it wasn't behaving as I expected. I diagnosed the problem as an irregular supply voltage from a 7805 voltage regulator. I am supplying it with 15 volts (also tried 12 volts) and getting 5 volts out. When the resistance of the circuit is low...
  6. Steventyj

    Electronic swtich, multiplexer?

    Thanks for the advice guys, I think this should do the trick Quad 2:1 Mux/Demux BusSwitch http://www.pericom.com/specs/PI5C3257.pdf
  7. Steventyj

    Developing a robotic app

    Have you considered changing direction though some kind of a mechanical system.
  8. Steventyj

    Electronic swtich, multiplexer?

    I am looking for a single chip that can take a number of inputs (preferably 16) and based on the signal of one digital control input forward a set of 8 of them to outputs. A made up example to clarify: We have 8 sensors for use in the day and 8 for use in night, and we can only process 8 of...
  9. Steventyj

    Repair vs Replacement policies

    Sorry, I think my question was misunderstood. When I said companies I meant end-user companies. As in, what does a mill do when they have a 6 year old motor (no warranty) that fails.
  10. Steventyj

    Repair vs Replacement policies

    I would like to thank everyone for the help I have recieved directly and for the knowledge I have gained by reading other peoples threads. I am wondering how companies make replace or repair decisons for thier electric motors. As far as I can tell the following would be factors in the...
  11. Steventyj

    3-Phase Squrrel Cage Well Pump Motors

    I would find out all of the nameplate information on some of the motors that had service lifes of 20 years +. Maybe someone decided to buy motors with a SF of 1.0 instead of 1.15 etc.. I would also take current draw readings of the new motors when they are full load to check if a re-evaluation...
  12. Steventyj

    Brushes

    Some more details would be helpful. Specs on the motors. How long have they been in service and what is the application. If the brushes are all wearing evenly then I would look into changing to a different brush that will carry a higher current density in your application. Are all of your...
  13. Steventyj

    Stator failure 6kV synchronous motor

    Was the idle mode a common mode of operation or was it associated with something unusual such as an area shut down? Have you had a chance to give a visual inspection of the stator to rule out the obvious causes such as contamination/moisture? If you do not look for electrical faults in your VA...
  14. Steventyj

    Standard Color for indicator lights

    "wired1 (Electrical) Mar 14, 2003 When was the last time anyone saw a green emergency stop button? " I think this is a great point. How would you have red as the color for emergency stop and for running? What are peoples experiences with equipment that uses red for running? Do...
  15. Steventyj

    Increasing current requirements with age

    The motors are not rewound, if they were we would have core loss tests to check that the core laminations were not damaged. The motors are currently being repaired in house. We are continuing different things with the bearings and have a new type on order but the feeling of our experienced...

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