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  1. jims99

    42V automotive system. What's the latest?

    Thomas, Since most of us have no access to this publication, can you share with us summary of article. Regards, Jim
  2. jims99

    "CircuitMaker 2000" PCB Design program (sch & layout)

    I work for a small company and we need to invest in a new, low cost, schematic capture and pcb layout program. I am considering "CircuitMaker 2000". (costs $995.) Our pcbs are simple in nature - typically no more than 100 components, mostly 2-layer, THT & SMT (future 4-layer?). Program should...
  3. jims99

    42V automotive system. What's the latest?

    I know the industry several years ago was picking up steam in designing future vehicles with 42V system. I recently heard rumors that none of the major car manufacturers are actually doing it soon, and in fact some manufacturers abandoned completely future plans. Anyone has info? Jim
  4. jims99

    Wiring an LED Bargraph to act as a meter

    I agree that LM3914 is the best way to go. One can always duplicate the circuit by using a few quad comparators (e.g. LM339) with a string of series voltage-divider resistors. Reference: the LM3914 data sheet: www.national.com/ds/LM/LM3914.pdf and go to page 6. jim
  5. jims99

    What is the best engineering advice you ever received?

    Always QUALIFY your designs by one or more methods: 1. By analysis (calculations, theory) 2. By experimentation (bench tests, stress test, subject it worst case) 3. By similarity
  6. jims99

    Al E-Cap

    If you really plan to opearate the electrolytic cap at 85 C, make sure you always specify a much higher rating such as 105C or better 125C. Also, use "computer grade" types that have lower leakage current and have lower ESR (equiv-series-res) to minimize self-heating effects. They may cost...
  7. jims99

    difference between op-amps and comparitors

    Yes, both can be used for each other, but it's not advisable. A comparator is specifically designed with very very high gain, and is also designed to provide a fast and "clean" transition. If you used it as an op-amp, the results are unpredictable, but most likely it will somewhat work. Since...
  8. jims99

    electrical line load loss

    mcb, Based on your proposed loads you should be fine. Quick and rough calculations, with assumptions: 1/4hp @220vac is about 3 amps 2 x 100W light bulbs: ~ 1 amps Charger: 1 amp Total: 5 amps. #6 wire is rated around 70 amps so obviously you have plenty of margins here. Voltage...
  9. jims99

    220 and 110

    Joe, You need to be careful and identify all the components inside your machine, then evaluate each one for its 110 vs 220 operation. For example if you have a “universal” power supply rated 85-250vac, then it’s ok, but if you have a resistive load (heater?), or a motor, you will not benefit...
  10. jims99

    component engineering

    hi keremsencan, There are some new books available that you can purchase, in the range of $50 - $100 (USD). However, may I suggest a book that I have and have used for years, titled “Electronic Components Handbook” a hardcover textbook, author: Thomas Jones, published in 1977. Obviously it’s...
  11. jims99

    Hi Temp cables

    Sparky, Olflex is a company that specializes in flexible wire/cable. They have a silicon based insulation wires/cbles rated 180C. Link to one of their catalog pages: http://www.olflex.com/Spec_Template.asp?nGroupID=7020 jim s.
  12. jims99

    Maximum current surge calculation for hook up wire

    Hinged, The other posts are all correct. What you need to concern yourself with in this application is electrical SAFETY. In the event of a single fault condition, such as the solenoid being “stuck” on continuously, the wire will be subjected to continuous 10 amps, that may cause insulation to...
  13. jims99

    Maximum current surge calculation for hook up wire

    The wire you’re describing has capability of carrying about 8 amps continuously, at 80C. (Ref: Alpha Wire chart: http://www.alphawire.com/PAGES/383.CFM ) However, generally you would not want to push it to its specified limits (will cause wire to heat up). A good and conservative rule of...
  14. jims99

    Where does "Mil" come from

    I'll stay out of the political dabate (but I'll just add that I'm in the U.S. and I do favor the metric system). Responding to torch - sounds like the term "mil" is used differently in the metric world as you pointed out to millimeters. Here in the U.S., if I say "The sheet of...
  15. jims99

    Project Management Software

    I would highly recommend Microsoft Project. It's a mature product and I believe it's the most widely used program - big advantage as you can find dozens of learning books. Although it has many features, one can use in its minimum mode for basic scheduling. jim s.
  16. jims99

    Historical question û origin of EIA resistor (mistaken?) values

    Thanks electricuwe and advidana for your insights. I tried calculating with coarser roundoffs and truncations, but this didn't yield better results to justify chosen values. For example, when I used 1.21 as k, things got worse as six values were off (instead of five). And you may note that...
  17. jims99

    Leakage Current

    Shajan, Just to expand on jtsamuals good comment, here are a few links showing circuits that should help you learn more: http://www.quadtechinc.com/newsletter/035101.pdf http://209.35.218.36/downloads/Leakage_Part2.pdf http://www.pema.ie/pdf/sllt.pdf jim s.
  18. jims99

    Historical question û origin of EIA resistor (mistaken?) values

    We all know the standard (5%, 10%, or 20%) EIA resistor values. For example, the E12 series (10%) are 10, 12, 15, 18, 22, 27, 33, 39, 47, 56, 68 and 82. These values were supposed to have been derived from the mathematical series of equally spacing values logarithmically for each decade(*)...
  19. jims99

    Historical question û origin of EIA resistor (mistaken?) values

    We all know the standard (5%, 10%, or 20%) EIA resistor values. For example, the E12 series (10%) are 10, 12, 15, 18, 22, 27, 33, 39, 47, 56, 68 and 82. These values were supposed to have been derived from the mathematical series of equally spacing values logarithmically for each decade(*)...

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