BC327/337 replacements

[udip]

Hi everyone!!

I'm having problems getting BC327-40/BC337-40.
Anyone knows a good replacement?

Thanx.

[peranders]

This is a very ordinary transistor but with a bit more current than usual. I doubt though that this is an important parameter.

You can replace these types with almost any transistor but if you explain more where in the design they are I can give you a more precise recommendation.

The "40" suffix means hfe more than 400 which could be tricky to find but it's not for certain that you need this. I have a bunch of BC550C and BC560C which may fit.

C = "40"

[udip]

Hi peranders,


The transistors will be at the output of the ELEKTOR discrete
opamp.

Do u think the BD139/140 is overkill for that?


Udi.

[peranders]

BC550/560 will probably work OK but BD139/140 is also OK. Check this for inspiration.

337 can take a bit more current but I doubt that this an issue.

[udip]

Originally posted by peranders

337 can take a bit more current but I doubt that this an issue.

How come the 327/337 can take more current than the
139/140??

327/337 are rated 500ma while the 139/140 are 1500ma..

And if I'm using the 139/140 do u think I'll need to bias them
harder than the 327/337?


Udi.

[udip]

BTW. You have some really nice projects on your site..

[peranders]

Originally posted by udip

How come the 327/337 can take more current than the
139/140??

327/337 are rated 500ma while the 139/140 are 1500ma..

And if I'm using the 139/140 do u think I'll need to bias them
harder than the 327/337?

.... 500 mA vs. 1500 mA which is more?

Originally posted by udip
And if I'm using the 139/140 do u think I'll need to bias them
harder than the 327/337?

You can probably have the same bias but the base current will be at least 4 times more so pay attention to this.

I see no problem to use BC550/560 though, 15 mA => 225 mW => not too much

[udip]

Thanks..

[udip]

Originally posted by peranders

I see no problem to use BC550/560 though, 15 mA => 225 mW => not too much

Forgive me for my ignorance in this area, but shouldn't higher
current capability should be a plus?

If I use the BC550/560 instead of the originals (BC327/337)
than I'll have less output current, am I wrong? so
why using weaker transistor will not cause problems?

Maybe It's my english (that is my second language), but when
u say "can take" a bit more current, you mean more driving capabilities, right?



Udi.

[peranders]

Originally posted by udip
If I use the BC550/560 instead of the originals (BC327/337)
than I'll have less output current, am I wrong? so
why using weaker transistor will not cause problems?

How heavy will your load be at the output? If you know that you will also know how much output current you will need. For a normal preamp application I'd say BC550/560 will do.