Transistor "kits"

[rsfoto]

Hi,

I know I am a bit late but for a beginner I would like to know is this would be a good assortment of transistors.

Thanks

The selection you show are good for low power circuits.

As has been said in this thread, it just depends on what you actually need, what do you intend to try building?

Regards,
X

Thanks. I am a 72 year old retiree and filling up my time with little projects to keep me busy     

I have a lab power source KORAD KA3305P, a frequency generator Siglent SDG2042X, a digital multimeter Siglent SDM3045X and a 2 channel Oscilloscope Siglent SDS1102CML+.

Nothing specific at the moment just browsing the internet and if I see an interesting circuit, I build it. I have already done a few simple circuits for some Arduino boards for opening automatically the roof of my astronomical observatory and using optocouplers for the safe and unsafe positions of my telescopes.

At the moment I have an electret capsule running and amplified via an op-amp LM358N as I wanted to measure the frequency of a home built mechanical sirene. Maybe then add an amplifier for connecting a loudspeaker. For adjusting the op-amp circuit I used the frequency generator and the oscilloscope.

[Xena E]

Not a complete beginner then. You have some decent test gear already.

A few general purposes transistors like the ones you list is good to have to hand. For any more specific types you can buy when needed.

Good luck.
X.

[rsfoto]

Not a complete beginner then. You have some decent test gear already.

A few general purposes transistors like the ones you list is good to have to hand. For any more specific types you can buy when needed.

Good luck.
X.

Thanks. Beginner in terms of using transistors   

[shapirus]

Hi,

I know I am a bit late but for a beginner I would like to know is this would be a good assortment of transistors.

Thanks

I have this kit or one just like it. I think coming from the same source. Chinese stuff. It came in handy several times already. Of course these transistors are not likely to be genuine (but they don't state any specific manufacturer, either), so they won't necessarily meet the datasheet absolute maximum parameters and you cannot be sure about their voltage breakdown thresholds until you test them (which is feasible), but:

- it's cheap
- it has a bunch of assorted parts in one handy box
- it has transistors with various pin arrangements like CBE, EBC, ECB in NPN+PNP pairs

So it's a great kit for a hobbyist and even a repairman, provided that we aren't talking about medical, military or other applications where a human life or other important matters may depend on them.

[magic]

Yeah, pinout is probably the biggest difference between these transistors. Plus types like BC327/337 or 2N2222/2907 are bigger than 2N3904/3906, or at least should be bigger - I don't know how it works with those cheap Chinese stuff, they could possibly be all the same inside. Power transistors for example are notoriously faked

If you care about quality and peace of mind, you could buy similar transistors from some reputable vendor.

[shapirus]

Power transistors for example are notoriously faked

Yes exactly. I wouldn't recommend getting fake power transistors from dubious sources (for example, even Chinese brand transistors are usually fake on e.g. Aliexpress), unless you know exactly what you're doing, that is, you can test them to make sure that they meet requirements of a specific application.

But with these generic TO-92 parts... why not? There's not much that can go wrong with them, and it's valuable to have an assortment for situations when you happen to need just that exact pinout that you'd otherwise need to make an order for and wait a few days.

[Thor-Arne]

Not sure about kits, it depends on what you are planning to do.

If it is repairs, kits will most likely not be sufficient.

If it's for projects (i.e. breadboard, birds-nest, prototypes) you have a lot more freedom to pick your own, great deals can be had if you are looking in the "on sale" category.

In my case, most of the time I only need a transistor to drive a relay so I can more or less pick what is cheap.
I have a selection (10 to 25 each) of the 5-10 most common ones seen, and I went for on-sale items for my own designs.
Got a couple of reels some years ago (4000 on tape) BC327-40 and BC337-25, think the price was less than USD 10 delivered from Elfa Distrilec.

I.e. BC546C at Elfa right now.
These on-sale pages is in my opinion the best solution to build stock for a hobbyist.

For me it's important to have what I need in-house in most cases, and at the same time save space.

I do have some IC's from China, but I try to avoid buying from there since it's so common with fakes.
You can find reliable suppliers in China, like on alibaba, but be prepared that they will give you a minimum quote that is not meant for the general hobbyist.

[magic]

But with these generic TO-92 parts... why not? There's not much that can go wrong with them, and it's valuable to have an assortment for situations when you happen to need just that exact pinout that you'd otherwise need to make an order for and wait a few days.

Problem is, I have heard of instances when even TO92 transistors from China had wrong pinout.
Looks like some factory got an order for transistor A, only had a stock of transistor B, printed A markings on B, what could possibly go wrong?

And of course there are differences in breakdown voltage or max collector current. You may see no difference in a 5V/5mA circuit, but see a difference when trying to switch 0.25A.

[shapirus]

But with these generic TO-92 parts... why not? There's not much that can go wrong with them, and it's valuable to have an assortment for situations when you happen to need just that exact pinout that you'd otherwise need to make an order for and wait a few days.

Problem is, I have heard of instances when even TO92 transistors from China had wrong pinout.
Looks like some factory got an order for transistor A, only had a stock of transistor B, printed A markings on B, what could possibly go wrong?

Yeah that's possible. I should have clarified that these kits should not be fully trusted until verified (and as a matter of fact, these days this should probably be applied to many more components that only those we're talking about).
Meaning, at least the pinout should be verified using transistor testers or other means, blindly trusting the datasheet is not always the best idea. I do this with every part that I'm about to use, not only to test the actual part, but to avoid my own mistakes too, and this includes parts from reputable suppliers as well.

And ideally, a device such as DY294 can/should be used to check the breakdown voltages in case of dubious origin of the parts.

I did not mention this initially, because it's kinda self-evident for me, but of course it may not be for others, so it's worth mentioning of course.

Current handling capacity can also be tested, and this one is probably the easiest of all.