Some tooling questions

Discussion in 'General Electronics Chat' started by fiberchunks, Mar 16, 2007.

  1. fiberchunks

    Thread Starter New Member

    Mar 16, 2007
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    0
    Hi all,
    First post here, and I'd just like to say thanks for an excellent site.

    I'm getting back into electronics, and slowly acquiring gear. I've searched the site, and have one particular product in mind that I'd like to get, but I haven't been able to find any reviews on it.

    I've been thinking about getting the WD1002 soldering station for a couple of reasons: 1) Weller makes quality gear, and 2) I'd like to get my son started in electronics, and it seems that with dual outputs, we could work on a project together.

    Are these statements accurate?

    Also, can you all recommend a decent oscope for around $400 - dual trace, etc.

    Another is a good DMM (are analog meters even necessary these days?) I've currently got a craftsman that I've been using for silly things, but I'm wondering if my buddy who borrowed it farked it by measuring resistance while a circuit was powered (it always reads around 132kOhm, unless actively measuring something -- I would think it would measure 0 unless it's measuring).

    Thanks very much for your time,
     
  2. thingmaker3

    Retired Moderator

    May 16, 2005
    5,072
    6
    Yup. I'll never give 'em up!! On more than one occasion I've had a co-worker fully perplexed & befuddled by their DMM readings - then used my analog and instantly seen a cap charging or a pulsed signal.

    I've no experience with the WD1002, but every Weller I've ever used has been a good tool. I think its pretty cool that you and your progeny will be working side by side!
     
  3. fiberchunks

    Thread Starter New Member

    Mar 16, 2007
    4
    0
    Thingmaker,
    Any brand of analog meter in particular that you're fond of?

    Yah, mostly, I'm getting back into it to make myself more sellable in the real world, and I'm trying to get him into it via the 'cool' robotics route. He seems excited. :)

    Don't want to pester, but do you have any idea why my DMM would read resistance when the leads aren't connected to anything (and the COM / Red leads are indeed in the right place, dial is set correctly, etc). As I mentioned above, my meter is reading 132kOhm or so when there is no resistance being read (or rather there is infinite resistance, since the leads are in air.) I'm worried about this because I want to ensure that my meter is functioning properly.

    Thanks again,
     
  4. thingmaker3

    Retired Moderator

    May 16, 2005
    5,072
    6
    I've got a couple of cheap "no-name" analog meters that I throw in the bottom of my tool bucket. They're good enough for checking continuity, presence of voltage and such things. When I need accuracy, I break out the Simpson P260. I've never used anything I like better than the Simpson. Other folk will have different opinions, of course.:)

    Regarding your Craftsman, does it read resistance accurately? Or is the 132Kohm open circuit the only symptom? What do you get, for example, when you try to read a 470Kohm resistor?
     
  5. fiberchunks

    Thread Starter New Member

    Mar 16, 2007
    4
    0
    yes, apparently it's measuring resistance right (but I'd like it if you'd double-check.)

    I found a resistor lying around that has the following scheme:
    yellow, violet, brown, and gold, so I'm guessing that the value is:
    4,7, 10Ohm multiplier +/- 5% (470 ohm.)

    The meter read 460 Ohm, so it seems to be reading correctly. I just wish I could figure out why an open circuit would have any resistance at all besides infinite?

    Thanks Much for your help,
     
  6. thingmaker3

    Retired Moderator

    May 16, 2005
    5,072
    6
    You do remember your color code correctly. :) Your meter does seem accurate when reading values below 132Kohm. Now you just need to find out if it is accurate enough above 132Kohm.

    Most DMMs will indicate overscale, or "OL" when reading an open circuit. They actually measure resistance by measuring current at a known voltage.

    Do your batteries wear out prematurely?
     
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