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Breadboard suggestions — Parallax Forums

Breadboard suggestions

NewStamperNewStamper Posts: 33
edited 2008-02-25 15:51 in BASIC Stamp
Dear members:
What features should a breadboard have so that I do not throw my money away on some thing basic that I will have to retire in the near future. Any ideas what I should look for and what accessories do I need to get a kit going? I think I do not want to spend $70. Most bang for the buck is what I like.

Thank you
NewStamper

Comments

  • ForrestForrest Posts: 1,341
    edited 2008-02-23 04:28
    Bigger is better. Parallax sells a nice one for $19.95 www.parallax.com/Store/Microcontrollers/BASICStampModules/tabid/134/txtSearch/breadboard/List/1/catpageindex/2/ProductID/421/Default.aspx?SortField=ProductName%2cProductName

    allelectronics.com also has good prices on breadboards and a jumperwire assortment

    If you need it today - RadioShack also stocks them at a somewhat higher price along with a jumperwire assortment
  • Bill ChennaultBill Chennault Posts: 1,198
    edited 2008-02-23 04:41
    NewStamper--

    Get the biggest one you can find. Parallax has a great one. Look at this great Parallax breadboard. Jameco has good breadboards. (Well, almost everyone does, I suppose.) Take a look at this Jameco breadboard. I like the Jameco breadboard . . . because it is the one I have! Plus, it has connections for power and a metal base that can be mounted on something, if you wish. I mounted mine on Ugly Buster, whom appears below. (Pay no attention to the 9mm ammunition boxes used as robot blocks. I have other hobbies, too!)

    SS-10-29-07.jpg

    The main thing, if you are new like me, is to get a breadboard that has enough area for you to "spread out" your connections. This adds clarity to your thought processes and allows you to "put something over there to test that may or may not become part of the main thing."

    --Bill

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    You are what you write.
  • UghaUgha Posts: 543
    edited 2008-02-23 06:18
    Another way to go is get a lot of small ones.

    Parallax sells a tiny one (I believe it's the same one on the BOE) that'd be great for small applications.

    What I like are interlocking small breadboards. You can build one section of your project, test it then
    go on to the next section, clicking the breadboards together as you go until your completely prototyped.

    Electronic Goldmine has a nice interlocking breadboard. The URL is:
    http://www.goldmine-elec-products.com/prodinfo.asp?number=G9849

    It's called the Super Breadboard, although I'm not sure why its super, its the smallest they have.
    They even have adhesive on the back if you ever want to stick them on a finished project.

    I have two of those and one of the "Large Universal Breadboard". It's nice cause of the power lanes
    on both sides. URL:
    http://www.goldmine-elec-products.com/prodinfo.asp?number=G8534

    Pretty much any electronics site is going to have some nice breadboards.

    A lot of people will recommend the really expensive ones with built in power regulators, I wish I could
    afford one but I can't. Until then, a regulated wall-wart or a converted PC power supply (what I use)
    works for when you don't want to waste batteries. (rechargables are also a must in my opinion).
  • NewStamperNewStamper Posts: 33
    edited 2008-02-23 07:11
    et al:
    Thank you for nice suggestions.

    Bill and Forest: I like your comment. Bigger is better. I was planning to get a small one so that I can carry it in my pocket and work on circuitry when in a traffic jam!!!!!
    Bill, 9 mil is accurate but 45 is my choice, as I have a few other hobbies too; not sure if it would some how tag along my robot......smile.

    Ugha:
    I like that price.
    How did you convert a PC PS into a regular PS. Last I remember, the PS gives no current unless it is connected to the mother board. Mind explaining?
  • UghaUgha Posts: 543
    edited 2008-02-23 12:31
    It's not that hard but it can seriously screw things up if you don't do it right...

    There are two wires in the largest connector on the supply... the one that's supposed to power the motherboard.

    One is a "Is the computer on?" wire, and one is a ground.

    You just cut those, put a switch on it tying them together, and boom, you got a desktop power supply.

    I bought mine already converted but I've done others in the past (a LONG time ago). There are several guides
    on the net to help you figure out which wire is which.

    Until I bought this one, I always thought it was a green wire and a black one, but it seems you can't go by
    that because this one has a black and a white. Make sure you know what your doing before you attempt it.

    I don't know if all of them are like this (In the past I didn't have a multimeter) but mine "leaks" power when
    the switch is turned off... sometimes as much as +0.8v. I get around this by simply unplugging it when I want
    to swap circuits around and such.

    There's also an issue with capacitor discharge... my power supply can retain a charge as much as 20 seconds
    after being unplugged... I haven't tracked the voltage yet but its enough to keep an LED lit.

    I don't know how "safe" a converted power supply is. I have no O-scope so I can't tell how steady the flow is
    and I haven't checked how much current it can handle... so I wouldn't use this to power a Stamp. I simply
    use it when breadboarding LED layouts and transistor configurations and the like.
  • ColtColt Posts: 24
    edited 2008-02-24 02:09
    ·· Most PC power supplies ( and all I've ever seen ), yellow is 12vdc, red is 5vdc. There is also -12, +3 but I dont recall which is which ( +3 I think is the orange wire ).· Most also have labels on the side that tell you which is which.. I use them a lot.. I do a lot of computer work on the side for people, if I upgrade their power supply I just stash their old one and use it for hobby stuff..· I figure if it's clean enough to run a PC, and good enough for a Stamp.. I've never had any problem running a stamp from one, I've used a stamp to switch the power supply on and off too. You can pick up a 150W PC power supply for less than 20 bucks if you look around..

    ·I have all different size bread boards, like Ugha, I like the small interconnecting boards, makes it nice for small projects and add on circuits.
  • NewStamperNewStamper Posts: 33
    edited 2008-02-24 05:00
    Thank you Colt and Ugha:

    I have a few PS laying around too. Let me visit those wires.
  • Mike GreenMike Green Posts: 23,101
    edited 2008-02-24 05:57
    Be careful in using PC supplies. They often have a substantial minimum current drain for the +5V supply. The regulation doesn't work well if you don't have at least that minimum current drain. You could burn out your Stamp (or whatever). Some of these work fine, but check first.
  • ColtColt Posts: 24
    edited 2008-02-24 06:02
    ·· Havnt ran across that yet, but I'll keep that in mind, thanks......·· I've checked them in the past with no load, after time though I quit checking, shouldnt always assume I guess jumpin.gif
  • UghaUgha Posts: 543
    edited 2008-02-24 07:26
    Like I said... its dangerous.

    I think just several kinds of rechargable batteries and some adapted wall-warts would be better. (Watch out for unregulated
    wall-warts though! As Mike has taught me, 99% of them aren't regulated!)

    Oh... a good way to get battery packs hooked up to breadboards: Find some capacitors or resistors with long, thick leads
    that fit well into your breadboard, cut the leads off (not too short, don't wanna waste a nice cap or resistor!) and then
    solder them onto the stranded wire of most battery packs. Then just cover all but a bit of the wire with electrical tape or
    heat shrink.... boom, instant breadboard interface.

    I find this works much better than tinning the leads, as tinning can make the leads oddly shaped if done poorly (like I do)
    which means they won't fit too good into the breadboard.

    Also tinning stranded wire tends to make it break right above the tinning if its used often in breadboards (all the plugging
    and unplugging). The electrical tape/heat shrink takes some of the stress off the wire so this happens less with my
    lead-soldering suggestion.
  • NewStamperNewStamper Posts: 33
    edited 2008-02-24 15:36
    Wisdom is worth a ton of money and grief, if not more. Thank you for your warnings.

    I think a sense of light just struck me. Can I not use any of the regulators that are lying around either from my various cell phones or some other applications. I need to find one that would output 5 Volts, right?

    Ugha said, "...As Mike has taught me, 99% of them aren't regulated!)
    And, how do you know/find out if one is regulated? If multimeter says 5 volts for the duration that I am checking, would that not be enough to see if it is regulated?
  • UghaUgha Posts: 543
    edited 2008-02-24 18:09
    I have the same problem. I've got over 20 wall warts lying around and I have no way of knowing if they are regulated or not.

    From what Mike Green has said in the past, it doesn't matter how much voltage it puts out at no-load... you'd have to test at
    light load AND full load. I'm not sure how to even start going about that, and I think you'd need a barrel jack for that as well.

    The best way is to check the datasheet for whatever wall-warts you have lying around. I've checked for 9 of mine so far with
    no luck... the info just isn't on the net.

    I've decided to crack down and buy the one Parallax sells... if you can't find the datasheets for yours, I recommend that you
    do the same.
  • Mike GreenMike Green Posts: 23,101
    edited 2008-02-24 18:24
    Ugha,
    Invest in a multimeter at RadioShack. Something as simple as this $10 one will do: www.radioshack.com/product/index.jsp?productId=2103534&cp=&sr=1&origkw=multimeter&kw=multimeter&parentPage=search.

    You can get fancier if you've got some extra money: www.radioshack.com/product/index.jsp?productId=2103176&cp=&sr=1&origkw=multimeter&kw=multimeter&parentPage=search.

    RadioShack sells some power resistors. The 10W ones on this page can be used for power supply loads: www.radioshack.com/family/index.jsp?categoryId=2032267&cp=2032058.2032230. The 50 Ohm resistor will draw 100mA at 5V which is a good test load for most wall warts. For a light load, use a 4.7K resistor of any size. That's around 1mA at 5V. Do check the wall warts at no-load. Most regulators can be damaged at voltages much above 30V. (The above suggestions were calculated from Ohm's Law: Voltage = Resistance x Current. You can figure this stuff out just as easily).
  • UghaUgha Posts: 543
    edited 2008-02-24 19:18
    I have several multimeters actually.

    I just had asked the process for checking the load voltage before and hadn't received an answer.

    Thanks for the info, this will help me a lot.

    Question: Does it have to be 10W?
  • Mike GreenMike Green Posts: 23,101
    edited 2008-02-24 19:28
    There's no "process" for checking the load voltage. That's probably why you haven't gotten an answer.
    There are two useful numbers ... the voltage at no-load or lightly loaded and the voltage at full or near-full rated current.
    If they're very close, then you have a well regulated power supply. If they're very different, you have a poorly regulated supply.
    The no-load or lightly loaded voltage is normally higher because various internal resistances of the power supply reduce the
    output voltage at high loads. If it's too high, it will damage what you connect to it

    Regarding the 10W resistor. You tell me. You can compute Ohms Law and the Power Law (Power = Voltage x Current) just as well as I can, especially these days with programmable calculators and spreadsheets.
  • MikeKMikeK Posts: 118
    edited 2008-02-24 19:28
    Power is V*V/R. If you're using a 50ohm resistor, at 5V the resistor is dissipating 0.5W. At 9V it's 1.6W. At 12V it's 2.9W. At 24V it's 11+W.
    If you don't want to burn your fingers (been there, done that), get at least a 5W resistor. 10W is best.
    Don't grab a resistor that you've connected as a load across a power supply without checking for excessive heat first.
  • allanlane5allanlane5 Posts: 3,815
    edited 2008-02-24 22:19
    Good point -- that "power resistor" dissipates that "power" by heating up. Most "power resistors" I've dealt with are high-resistance wire wrapped around a ceramic core. Dissipating 5 watts of heat (think "dim light bulb") to the ambient air results in quite a large temperature differential between the resistor and the air.

    Bottom line -- it gets REAL hot.· Not "peel your flesh from your bone" hot, but "raise a really good blister" hot.
  • NewStamperNewStamper Posts: 33
    edited 2008-02-25 15:51
    Thank you all for helping my learning curve. Very soon Ugha and I will be the best around the block........not sure about that, but thank you guys, including Ugha.....smile
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