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  1. E

    LM317 Variable power supply

    Uh...oops. ...and you're going to be reversing the voltage? How about output fusing that power supply first?
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    Calculating voltage output of Capacitor in AC Circuit

    Among notable others, my Boylestad & Nashelsky text is missing at the moment (my son claims innocence), so I'm left with Malvino's "Devices" text--and the like--from which the 3 graphics were scanned. Thus far, all other references that I have at my disposal concur with Malvino; either...
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    el34

    ...and, if it's good enough for AOpen, who am I to disagree??? ;) "Today AOpen shows us something that, while it could be considered revolutionary, may also be very "old school" to many of our readers out there. AOpen is putting vacuum tubes back onto the desktop platform. The pictures below...
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    Relatively new, looking for some basic answers.

    In thinking back on this some more (yeah, more than 30 years now), and checking my recollections against those of a couple of other guys who were in the same class with me (my phone bill is going to be high this month); we've been able to piece-together a bit more of a picture of what was said...
  5. E

    el34

    An AM transmitter was one of the first projects I built as a kid...the times have changed. Anyway, this is about as close to what I built, back then, as I can find: (attached)
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    Calculating voltage output of Capacitor in AC Circuit

    Forgot about this one...
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    Safety Capacitor

    I'd resort to the lame, "fine wine" remark, and beat you with my cane; but my momma taught me to always respect my elders. ;) ::: fleeing because I still can :::
  8. E

    Calculating voltage output of Capacitor in AC Circuit

    I went over capacitor input filters with my son around the mid-part of last year, and finally got my hands back on the books I gave him. I thought a couple of scans from the chapter on diode circuits might be of some help--either here, or in the future. (It makes a decent-enough reference sheet...
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    Cutting PCB's

    ::: cough ::: What dust? >hack-choke<
  10. E

    Oxodized Sodering iron

    ::: Slapping my forehead and laughing ::: Yup. Gotta pick up some more, now that I've been reminded what I'm looking for. ;)
  11. E

    Safety Capacitor

    Definitely not that old! :D Some of my favorite vintage equipment definitley dates back to the 30's and 40's; which gave me exposure to the engineering of that era. ...and I certainly forgot about DC switches arcing too.
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    Safety Capacitor

    This is an old (dates back to some time in the 1930's) technique of quenching switch contacts to protect them from arcing, pitting and poor service life. Most generally, I've seen 0.1uF, ceramic disc capacitors used across the contacts of 120VAC power switches, with working voltage ratings...
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    simple timer circuit

    My apologies. I had intended to go with a Lab curiculum sheet that I had open on one desktop, and got myself mixed up when I was referencing the Fairchild DS file on another desktop. At any rate, the attached schematic calls for the addition of a voltage divider (R4 and R5) to select the...
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    Relatively new, looking for some basic answers.

    To the issue of powering devices "for free"--because that's really what's being said, here--it can and has been done in the past. My, now dearly departed, high school electronics teacher (don't ask me how long ago that was) said that he personally knew a man he served in the Navy with, who...
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    Newbie needs an advice!

    Firstly, let me say that I admire your enthusiasm, as well as choice of Operating Systems. Here are a couple of references that I consider very valuable for anyone wanting to learn about electronics: http://hyperphysics.phy-astr.gsu.edu/hbase/hph.html and...
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    Oxodized Sodering iron

    We used to use a chemical--that I cannot, for the life of me, remember the name of now--to clean off oxide residue from soldering irons, before they started cladding the tips. It worked well on the clad iron tips as well, IIRC. I can say that I've seen Radio Shack # 64-020, and another item...
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    simple timer circuit

    Page 8 (Heading #4) of the attached PDF should help you out a bit. NE-555.pdf
  18. E

    CMOS Question

    If you're talking about digital ICs then you'd have the advantage of wider operating voltage ranges, greater noise immunity (as compared to TTL), and lower power consumption. I really don't know if, given the types of circuits you build, those characteristics would be of any benefit. Some...
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    UV exposure and white LEDs?

    I wish I could claim specific knowledge but, for some reason, I have a growing interest in making some sort of space-efficient exposure drawer for things like litho film and pc boards. If I come up with something interesting, I'll certainly share my findings.
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    BNC connectors in 50 and 75 Ohm cables

    Rats! I'd better toss-out my 'o'-scope. ;)
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