Transistors Replacements

I'm trying to build a circuit that calls for these three Transistors. My local guy does not have them. I would rather buy from him than some place I have to have them shipped into, added cost etc.

Who knows they may be obsolete?

Does anyone have a book or something where they can look up replacements for these that might be more available.

BC212 BD132 BC182

The circuit would like to build is at :

Thanks.

some place

replacements for

Hi, Chretien. If you can't find the specified parts for a hobbyist project, you might want to try NTE replacement semiconductors. They're made for repair and engineering prototype stuff. Their cross-reference page is

You can frequently find what you need there.

I did a quick search on their cross-reference page, and came up with the following:

BC212=NTE159 BD132=NTE242 BC182=NTE123AP

If you can't find NTE parts locally, you can always get them out of the Mouser catalog

(By the way, please wear eye protection when you use your NiCd zapper circuit. Also, try using a 12V automotive bulb as a load when checking out your circuit, before you try a battery.)

Good luck Chris

Thanks.

I am a novice and tend to slavishly follow schematics. However I know that many circuits can use as you say any old transistor. I don't always understand why, accept to say that I suppose the circuits are so heavy handed and non specific that almost anything will do so long as the are NPN or PNP.

Thanks again.

that

=============================== The rule of thumb is that the transistor needs to withstand the voltage and current from the circuit, so over spec-ing the transistor just hurts your wallet. Same with caps... you can use a 50v cap in a 5v circuit, but not vice-versa

In the well known electronics magazine Elektor they use the acronyms tun and tup to mean transistor universal npn(pnp).

The requirements for these transistor are something like this: Max collector voltage min 30V, hFE min 200, max current min 100mA.

Thousands, if not millions, of small signal transistors meet these requirements, and you can use any of them in most circuits. Elektor use those basic types in many of their circuits.

In your circuit 3 are such small signal transistors and there is no special requirements as far as I can see. The power source is

The BD type is a power transistor which need to be able to handle 2Amp momentarily.

There are circuits where other parameters mean a lot, like in an audio preamp if it says BC109c it means a low noise transistor with a hFE above

A well known tun is BC107 (108,109), a well known tup is BC177 (178,179). The numbers ending in 9 in these series denote low noise types, but they can take less maximum voltage. (30V instead of 60V for the 107 and 108 types) If there is a letter at the end it shows the hFE value.

BC107b = General purpose npn small signal transistor with medium amplification factor, hFE = 300-500 or so.

All numbers above are approximative, different manufacturers have slightly different values.

Check out these links:

Hey thanks thats that will be a great help in the future.

amplification

Roger,

Thanks for the tutorial it was extremely helpful. Here and I thought all those letters where just manf codes. I'm printing off your message and will keep it in my transistor file for future reference. The web links were very useful also. I have actually made a few of Mr Toons projects but somehow didn't see those links.

I have to say this newsgroup is one of the most helpful I have ever used. I always seem to get some help when I need it.

Thanks again.

those are generic type PNP and NPN signal transistors. from what i can see.