Transistor Question

[Tripmaster]

Hello

I am currently building the Pedja Rogic’s discrete power supply for my dual mono Chipamp LM3886.

I have assembled the V+ section of the power supply and have started positioning the components for the V-. I have just noticed the component supplier has sent three types of BD140 Transistor.

BD140, BD140-16 and BD140-16R4

Is it ok to use a BD140 and a 16 in the same circuit?

It looks like they are also from three different manufactures.

Thanks for your help

Richard

[Nuuk]

Not sure Richard. Best to ask Cricklewood!

[Tripmaster]

Originally posted by Nuuk
Not sure Richard. Best to ask Cricklewood!

Hi Nick

I was really unimpressed with their attitude when I chased a late delivery. I wanted to be armed with the facts before I call them.

I’ve looked on various spec sheets but cant seam to find any useful information.

Richard

[Tripmaster]

I just called Crinklewood and spoke to Chris who was very helpful

‘-16’ refers to a plastic back transistor and ‘R4’ is the metal back version.

He also said all of the transistors regardless of make will perform in exactly the same way.

[lineup]

Yes, they are basically same transistor.
There can be some variation in HFE, gain.

BD140-16 .. is the most usual, lowest gain class ( ~160 )
BD140-25 .. is a class for those exemplars with higher gain ( ~250 )

BD140 .. only, can be in any gain span, is not classified and marked
with any of the above

Personally I have never seen any marked R4. The metalback.

[Tripmaster]

Originally posted by lineup
Yes, they are basically same transistor.
There can be some variation in HFE, gain.

BD140-16 .. is the most usual, lowest gain class ( ~160 )
BD140-25 .. is a class for those exemplars with higher gain ( ~250 )

BD140 .. only, can be in any gain span, is not classified and marked
with any of the above

Personally I have never seen any marked R4. The metalback.

Thanks for the info.

Would you recommend I change them all to the same type?

Richard

[mjf]

hello all to you.
the number behind the bd 140 - designation is the hfe-classifikation,there are some from 6,10,16,..............the bigger number means the greater hfe-value.
what hfe - (minimum )value you need depends on your circuit design..........
greetings.........

[Tripmaster]

Originally posted by mjf
hello all to you.
the number behind the bd 140 - designation is the hfe-classifikation,there are some from 6,10,16,..............the bigger number means the greater hfe-value.
what hfe - (minimum )value you need depends on your circuit design..........
greetings.........

Hello again

I am building the power supply schematic at the bottom of this page

Discrete Regulated

http://myweb.tiscali.co.uk/nuukspot/...p/supplies.htm

Richard

[mjf]

hello.
the schematic with the three-transistor-darlington?- i think this will give you enough current amplifikation (high hfe - value......).
but perhaps there will be a little problem with the heat-dissipation with loud music,i did not calculate it but i think yuo will need big heatsinks........
greetings.........

[Tripmaster]

Originally posted by mjf
hello.
the schematic with the three-transistor-darlington?- i think this will give you enough current amplifikation (high hfe - value......).
but perhaps there will be a little problem with the heat-dissipation with loud music,i did not calculate it but i think yuo will need big heatsinks........
greetings.........

So just to recap, can I use a BD140 and a BD140-16 side-by-side in the V- supply?


I was going to make some heat sinks like the ones in Nuuks picture.