Electronic components need suggestion

Discussion in 'General Electronics Chat' started by vead, Oct 12, 2013.

  1. vead

    Thread Starter Active Member

    Nov 24, 2011
    I want to make some circuit for my basic understanding with the help of resistor, diode, transistor, capacitor LED battery resistor, diode, transistor, capacitor LED battery. I want to purchase resistor, diode, transistor, capacitor LED battery But I don't what i say to shopkeeper what rating of component should i use
    can anyone help me tell me the rating of component that is used in mostly electronic circuit for above component I want to do just for practice
  2. ian field

    Distinguished Member

    Oct 27, 2012
    If you're worried about blowing your cash on the wrong components - go the free route by watching out for discarded TVs etc to harvest components, you can learn a fair bit just looking up the parts you've recovered just by sorting them for storage. Then look at the parts you have and browse the WWW for tutorials & projects that fit the parts you have, by the time you need to buy specific parts - you'll have more idea how/what to ask for.

    Most recent electronic items are mostly SMD - if you're using prototyping stripboard; look out for older stuff that may have more through hole components.

    As well as the most basic tools - a modeller's pencil blowtorch is good for harvesting components from scrap boards very quickly.
  3. wayneh


    Sep 9, 2010
    I agree with Ian and have been "harvesting" stuff for years. But I also buy stuff when I need it for a specific project, and that's what I suggest. Think of some projects that interest you and start looking for the needed parts.

    For a beginner, you should look for projects that do not involve high voltages, currents or power levels. Blinking LEDs is a favorite, for instance, and uses very little power. Under these low stress conditions, you don't have to worry much about the ratings of your components - any you buy will handle the job. As you move up to larger currents and voltages, you'll need to start calculating power dissipations and such. But that will be easier after you have learned more of the basics.
  4. bertus


    Apr 5, 2008
    Last edited: Oct 13, 2013
  5. ian field

    Distinguished Member

    Oct 27, 2012
    A novice can get a fair bit of satisfaction from lighting a white (or blue) LED from a single cell (1.5V) a very basic blocking oscillator/inverter can be cobbled together very quickly from most types of common mode choke found in SMPSU mains input filters - once you get the windings phased correctly.

    The novice will soon discover that this circuit can produce fairly impressive voltages - but you have to bias the transistor differently if you want to run it off more than a single cell.
  6. gootee

    Senior Member

    Apr 24, 2007
    It occurred to me that you might be wanting a list of particular general-purpose components that will form an assortment, for general experimentation.

    You could first ask if they have any bags of assorted components for experimenters or hobbyists, such as a bag of various types and ratings and values of capacitors, or a bag with many different values of 1/4-Watt resistors, for example.

    But if you are going to be experimenting, there are some components that you will probably want to have on hand (maybe 5 or 10 of each):

    Transistors: (plastic or metal case)
    2N2222 (NPN) and 2N2907 (PNP)
    or 2N3904 and 2N3906
    or 2N4401 and 2N4403
    or 2N2219A and 2N2905A
    Maybe some BD139 and BD140, or some other medium-power ones
    2N7000 FET

    Transistor sockets?

    1N4001 (1 Amp, 50V max) and maybe 1N4004 (1 Amp 400 V max)
    1N4148 or 1N914

    10 pF (picofarads) ceramic, NP0 or C0G type, 25 V or more
    22 pF ceramic, NP0 or C0G type, 25 V or more
    100 pF ceramic, NP0 or C0G type, 25 V or more
    220 pF ceramic, NP0 or C0G type, 25 V or more
    1000 pF ceramic, NP0 or C0G type, 25 V or more
    0.001 uF ceramic, NP0 or C0G or X7R type, 25 V or more
    0.0022 uF ceramic, NP0 or C0G or X7R type, 25 V or more
    0.01 uF ceramic, X7R type, usually 50V or higher
    0.022 uF ceramic, X7R type, usually 50V or higher
    0.1 µF (microFarads) ceramic, X7R type, 50V or higher (get more of these)
    0.22 µF (microFarads) ceramic, X7R type, 50V or higher
    1 uF polyester film
    2.2 uF polyester film
    10 uF electrolytic, 25V or higher (get more of these)
    22 uF electrolytic, 25V or higher
    100 uF electrolytic, 25V or higher
    220 uF electrolytic, 25V or higher
    1000 uF electrolytic, 25V or higher

    QUANTITY 2, 12V RMS output at up to about 1 Amp (or as little as 200 mA)
    or qty 1 with dual 12V secondaries, or, qty 1 of 12-0-12 center-tapped

    (get Metal Film 1% or Carbon Film 5% type, 1/4 Watt or 1/2 Watt)
    10 Ohms
    1k (1000 Ohms)

    Op Amps:

    Op Amp sockets?

    red, 20 mA or more

    Three-terminal Voltage Regulators?
    LM7812 (qty 2)
    LM7805 (1 or 2)

    RF Choke:
    1 or 2 of about 100 uH (microHenries), 1 Amp or more

    NE555 (or just "555") timer IC (two or more)

    Optional: MC34063A switcher IC (1 or 2) (very versatile, very simple DIP8 SMPS chip)



    Terminal Blocks?

    9-Volt batteries?
    (with wired snap-on connectors)



    Solder sucker (squeeze bulb)

    I am sure that I have forgotten some important items. But I am sure that someone else will mention them.


  7. ian field

    Distinguished Member

    Oct 27, 2012
    In the UK, the best hobbyists have is Maplin (rather pricey) - they do an experimenters pack of resistors, 10ea of every standard value from 10 to 1M. they also do lucky dip bags of capacitors etc. Its best to only deal with Maplin at the counter of one of their shops - the packers in the mail order warehouse wouldn't know an electronic component from a bicycle pump!!!
  8. MrChips


    Oct 2, 2009
    What about Farnell?
  9. ian field

    Distinguished Member

    Oct 27, 2012
    In theory you need to have a trader letterhead to do business with Farnell.

    As I was self employed repairing PC monitors, I was more or less telling the truth, but I dressed it up a little by adding "prototypes & small production runs" - so my low volume of orders didn't give the game away.

    I calculated that for some components; Maplin was charging as much as 13x what Farnell were!!!

    There can sometimes be a problem with Farnell - occasionally a part I want comes up as US stock and they want a one off per order shipping charge to make that (or those) part(s) available to a UK order.

    The only time I use Maplin is for immediate over the counter purchases - their mail order warehouse is run by people with negative IQ!!!
  10. gootee

    Senior Member

    Apr 24, 2007
    If the pricing is that high, I would consider ordering from mouser.com, in the USA. They are extremely fair (and low) with their shipping prices, to the USA. So maybe they would also be good for international. And they have no minimum quantity for the vast majority of their components. I have ordered from them many dozens of times and their service and accuracy have always been outstanding.

    For hobbyists without any local electronic components shop, I imagine that ebay.com could also be a good source of components. I haven't checked lately but in the past I always saw "grab-bag" type assortments of components, for hobbyists, there. I guess it might depend mostly on the seller's location and the shipping charges, but it's probably worth checking.

    Long ago, I used to just go to "yard sales" and buy used television sets, for $1.00 or so. No shipping cost and no waiting. I got pretty good at heating the solder side of a printed circuit board with a propane torch and then whacking the edge of the board on the ground to knock most of the components out. You can get a lot of nice film caps, that way, and lots and lots of other good stuff, especially from the really-old sets.
  11. MrChips


    Oct 2, 2009
    I don't know if this is correct. I thought Farnell/Newark/Element 14/ was the same company. I order regularly for private use without a problem.
  12. ian field

    Distinguished Member

    Oct 27, 2012
    The flats where I live have communal bin rooms that offer up the occasional TV or set top box - sometimes there's even a PVR with a hard-drive in it.

    The most recent haul was several digital cameras, a couple of mobile phones and a personal CD player.

    Much older mobiles sometimes contained pretty impressive UHF power transistors, these seem to be integrated into one of the chips these days, but the very tiny electret mic is excellent for making a bug.
  13. TorontoBob

    New Member

    Oct 5, 2013
    I agree with the comments of others about starting off with low voltage, low current projects. If you are running most things off of 9 or 12 volts, then as long as your capacitors are rated higher than that you will be fine. I wouldn't worry about "metal film" resistors at this point unless you are doing very low noise audio work or making your own meters. I would stick with the 5% carbon film 1/4 or 1/2 watt unless a circuit specifies otherwise.
    I see Elektor Magazine has an Indian site http://www.elektor.in and then there is Electronics For You another magazine. I would assume you can get those at the library or a local store, and they should have advertisements for local suppliers.
    When I started electronics over 4 decades ago, I got about half of my parts from salvaging thrown out electronics, though these days with surface mount parts, you should be looking for older electronics.
  14. sirch2

    Well-Known Member

    Jan 21, 2013
    I know this is off-topic but I have used Farnell for years and the only issue is the minimum £20 order. CPC is also owned by Farnell and are currently offering free delivery with no minimum order (they have most things but not quite the stock range of Farnell or Radio Spares). I'd also put in a word for Rapid Electronics who do some good experimenters packs at reasonable prices.

    To the OP, as others have suggested there is a fairly common range of parts but I would choose a circuit to build and get the parts for that initially. You will soon find it's cheaper to by 10 or 100 of a resistor or capacitor than buying just one so after a few circuits you will have a collection of parts in stock. You can then fill in the gaps as you need them.
  15. ian field

    Distinguished Member

    Oct 27, 2012
    IIRC - last time I ordered from Farnell, it was £35 MO - probably more by now.
  16. sirch2

    Well-Known Member

    Jan 21, 2013
    OK, but the crux of the point is you don't need to be a business or have a "letter head" to order from Farnell, not that has mean anything since everyone got a printer.

    BUT use CPC if they have what you need - FREE DELIVERY!!!