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Topic: List of parts for shopping (Read 957 times) previous topic - next topic


I wanna go visit the electronics shop for buying parts for my laser tripwire circuit.
I wanna buy resistors, capacitors, transistors.
Can somebody give me a list of commonly used resistors, capacitors and transistors.
I've searched for laser tripwire circuits and found a lot of them, but just in case there can you point me to a laser trip wire circuit. Also I don't want one with square wave generator as my piezo buzzer buzzes automatically.

Also recommend me some other commonly used parts if possible.
If you want to meet a beautiful nurse you must be patient.


For resistors, just get as many as you can of a wide spread of whatever values are available.  They're $0.01 each, if you can find them reasonably priced, so there's no reason not to get a lot.

Capacitors, I suggest buying a pack of assorted electrolytics and a pack of assorted ceramics, and some 0.01-0.1 uF film caps.

For transistors, I recommend mostly buying 2N2222s, 2N4401s, and 2N4402s.  Of course, 2N3904s and 2N3906s are slightly cheaper.  If they cost more than about $0.15 each you're paying too much for them!

I also recommend some diodes, both rectifiers and signal diodes.  Zeners too, if you think they'd be useful.

LEDs are always nice to have too; just buy an assortment.

And it's always useful to have an LM386 or three around.

Some logic ICs would be generally useful (74 series or 4000 series)

And don't forget a voltage regulator!  Buy several, since they're cheap and useful.  The 7805 provides a nice steady 5V output from a 7V+ input (and the 7905 provides a good -5V if you need a negative supply), or you can use an LM317 adjustable regulator to get any voltage you require.  Or you could get this kit: https://www.adafruit.com/products/184  Which is a complete adjustable voltage supply in itself.


Electrodragon sells kits of resistors, ceramic Capacitors, electrolytic capacitors , diodes and transistors, min 10 parts/bag and 10 - 20 values in each kit. I bought the capacitor kits (2 EA) and the diode kit. All the kits are ~$1.50 each, all new and all look good, not mis or un marked parts I already own more transistors than I know what to do with, so many as a matter of fact that I don't bother with them if the markings aren't standard Jedec numbers... 1NXX, 2Nxx 2SA, b, c, d, j, k or BCXXX. All are good parts I just don't care to even try them out since I have so many of the others. This guy isn't the only store but I did notice that he was cheaper than about 90% of the sellers on Ebay and the main reason that I recommend him.

--> WA7EMS <--
"The solution of every problem is another problem." -Johann Wolfgang von Goethe
I do answer technical questions PM'd to me with whatever is in my clipboard


Jul 01, 2012, 10:22 pm Last Edit: Jul 01, 2012, 10:29 pm by focalist Reason: 1
Lm317 are particularly good as they can also be used as a constant current driver for power LEDs using only a resistor to set.  A pair of LM317s and a couple of resistors, and you have an adjustable power supply with current limiting.

ULN2003 darlington arrays are super cheap switching transistor arrays, seven per chip..each chip can handle a total load of up to 500ma, enough for small stepper motors, led arrays, and many other mid power switching applications.  

A handful of logic level n channel mosfets for switching big loads

Assortment kits:  1/4 watt resistors, particularly 1k and 330 ohm.. For led's and base resistors.  Ceramic caps, and low voltage electrolytic.  Bulk packs of a few colors of LEDs.  2n3904, 2n2222 transistors.

Hop on ebay and get a couple of 5v gear-reduced stepper motors (and the uln2003 driver boards they sell with them), as well as a couple of hobby model servos.

If you buy off ebay from China, be prepared for things taking a month to arrive- but you can save a fortune buying this stuff off ebay from the wholesalers in China..

My secret when it comes to hookup wire..  go to a discount store and buy a spool of four-conductor phone line.  Locally, I pay two dollars for a 100 foot spool, which has four individually insulated 24 guage solid copper wires... No possible way to beat the price.  You can also use network cable the same way if it is cheap, just make sure it's the type with individual wires inside an outer sheath, and then you can just remove the sheath as needed and cut wire as needed.  Razor is nice for cutting sheath cleanly.


I love buying from China... takes twice as long... But you get generally twice as much... for the same money. Only 2 places I avoid one is Sure Electronics (They have 0 warranty {told me to"Ship back" a defective part and they "Would determine" if it was under warranty} and the other is SparkFun... I know SparkFun isn't in China but the prices are like single unit China pricing with a 20% markup. This by Comparison Shopping all the sites I could find on 3 continents, American, European and Asian. The best prices on 4D Systems parts come from Robot Shop. $79.00 for the 3.2PT SGC display VS $83 or $84 @ SparkFun and the connector to all the goodies hidden in the display is $34.00 on SparkFun and $20.00 on Robot Shop... I've bought 2 so far and wouldn't shop anywhere else.

--> WA7EMS <--
"The solution of every problem is another problem." -Johann Wolfgang von Goethe
I do answer technical questions PM'd to me with whatever is in my clipboard

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