Maker Pro
Maker Pro

different hfe's on these transistors

J

Johan Wagener

Jan 1, 1970
0
I bought the following transistors for an amplifier project. 2N5416
and 2N3440 made by CDIL.

I checked their hfe's and had the following result:

All the 2N5416's have hfe of 100 except one which had hfe of 66.

2N3440's had hfe's of about 69-72 except one which had a hfe of 58.

Is this ok?

Is the hfe of these transistors high enough? I checked the datasheets
and the specify hfe's of 40-160 for 2N3440 and 30-150 of 2N5415

Can I use transistors with different hfe's?
 
C

CWatters

Jan 1, 1970
0
Can I use transistors with different hfe's?


A good electronics engineer will design his circuit to tollerate worse case
parts. The spec says hfe can be as low as 40 or 30 and yours are higher than
that so you should be ok.
 
C

CWatters

Jan 1, 1970
0
I forgot.... sometimes it is necessary to use parts with a specific minimum
hfe. Normally in such cases the designer will specify you need the C version
of a transistor. For example they will specify you need a BC109C rather than
just a BC109....however this is very bad practice. It's much better to
design out the need for a specific hfe.
 
J

John Popelish

Jan 1, 1970
0
Johan said:
I bought the following transistors for an amplifier project. 2N5416
and 2N3440 made by CDIL.

I checked their hfe's and had the following result:

All the 2N5416's have hfe of 100 except one which had hfe of 66.

2N3440's had hfe's of about 69-72 except one which had a hfe of 58.

Is this ok?

Is the hfe of these transistors high enough? I checked the datasheets
and the specify hfe's of 40-160 for 2N3440 and 30-150 of 2N5415

Can I use transistors with different hfe's?

So you are saying that all your transistors are within datasheet
limits.

hfe is not a very well controlled parameter (typically varying over a
3 to 1 range in production). You had better learn how to design
circuits to handle this range of variation or trim every circuit by
hand.
 
S

Sofie

Jan 1, 1970
0
Johan Wagoner:
Your actual test results of the transistors were well within the
manufacturer's specified range that you posted.
If you need matched pairs for push-pull or parallel circuitry considerations
then you can use selected transistors based on the results of your tests,
otherwise they all meet specifications.
 
J

John Larkin

Jan 1, 1970
0
I bought the following transistors for an amplifier project. 2N5416
and 2N3440 made by CDIL.

I checked their hfe's and had the following result:

All the 2N5416's have hfe of 100 except one which had hfe of 66.

2N3440's had hfe's of about 69-72 except one which had a hfe of 58.

Is this ok?

They're in spec.
Is the hfe of these transistors high enough?

Depends on what you need.
I checked the datasheets
and the specify hfe's of 40-160 for 2N3440 and 30-150 of 2N5415

Can I use transistors with different hfe's?

Decent circuit designs are beta-variation-tolerant. Fixed base current
linear design is called "suicide bias"... some transistors may work,
and some may not. Design to work over the transistor's spec'd beta
range, or worse.

John
 
J

Johan Wagener

Jan 1, 1970
0
John Larkin said:
They're in spec.


Depends on what you need.


Decent circuit designs are beta-variation-tolerant. Fixed base current
linear design is called "suicide bias"... some transistors may work,
and some may not. Design to work over the transistor's spec'd beta
range, or worse.

John


This is for use in the leach amplifier.
 
J

Jason D.

Jan 1, 1970
0
I bought the following transistors for an amplifier project. 2N5416
and 2N3440 made by CDIL.

I checked their hfe's and had the following result:

All the 2N5416's have hfe of 100 except one which had hfe of 66.

2N3440's had hfe's of about 69-72 except one which had a hfe of 58.

Is this ok?

Is the hfe of these transistors high enough? I checked the datasheets
and the specify hfe's of 40-160 for 2N3440 and 30-150 of 2N5415

Can I use transistors with different hfe's?

I never heard of CDIL, but that markings usually screams "GENERIC"!
Didn't you got them for good price? If so that's the reason and and
are faked.

I got few stuff made by NSC and few of them looked real and had
correct brands too marked and I don't trust them either because of too
good to be true prices.

In audio stuff, close hfe values usually is preferred to get smaller
0V crossing distortations.

The large transistors made for high power audio stuff are in 20 to 40
dollars range not 5 bux range that generics abounds.

Cheers,

Wizard
 
A

Al

Jan 1, 1970
0
I never heard of CDIL, but that markings usually screams "GENERIC"!
Didn't you got them for good price? If so that's the reason and and
are faked.

I got few stuff made by NSC and few of them looked real and had
correct brands too marked and I don't trust them either because of too
good to be true prices.

In audio stuff, close hfe values usually is preferred to get smaller
0V crossing distortations.

The large transistors made for high power audio stuff are in 20 to 40
dollars range not 5 bux range that generics abounds.

Hfes from one transistor lot should be close. Variations are to be
expected between lots. That's why the range in the spec is so high. If
you want them close, you will pay extra for it. And most likely the mfgr
will just select them for you.

As an example, years ago, we tested a large lot of resistors of one
value we had purchased. The purchase tolerance was +-5%. Yes, They were
all in that range. But...there was a big hole in the plot at +- 1%. It
looks like the mfgr had separated out all the resistors that were +- 1%
from the lot and sold them as such. We got he +- 5%, which is what we
had asked for. We were too stupid to specify a normal distribution in
the resistor values.

The same will hold for almost any component you buy.

Al
 
J

John Larkin

Jan 1, 1970
0
This is for use in the leach amplifier.

Oh, audio. In that case, all rational design considerations are void.
File the corners off the packages or dip them in red wine or whatever
makes it sound best.

John
 
J

Jim Thompson

Jan 1, 1970
0
On 8 May 2004 03:26:07 -0700, [email protected] (Johan
Wagener) wrote:
[snip]
This is for use in the leach amplifier.

Oh, audio. In that case, all rational design considerations are void.
File the corners off the packages or dip them in red wine or whatever
makes it sound best.

John

ROTFLMAO!

...Jim Thompson
 
W

Watson A.Name \Watt Sun - the Dark Remover\

Jan 1, 1970
0
Jim said:
On 8 May 2004 03:26:07 -0700, [email protected] (Johan
Wagener) wrote:

[snip]
This is for use in the leach amplifier.

Oh, audio. In that case, all rational design considerations are void.
File the corners off the packages or dip them in red wine or whatever
makes it sound best.

John


ROTFLMAO!

...Jim Thompson


Yous guys should start circulating a claim among the audiophiles that
only amps and other audio electronics sound excellent if they were
designed and drafted with pencil and drafting board. Any audio
component won't have the right sound if it was designed with a lowly
computter program!
 
J

Jim Thompson

Jan 1, 1970
0
Jim said:
On 8 May 2004 03:26:07 -0700, [email protected] (Johan
Wagener) wrote:

[snip]

This is for use in the leach amplifier.

Oh, audio. In that case, all rational design considerations are void.
File the corners off the packages or dip them in red wine or whatever
makes it sound best.

John


ROTFLMAO!

...Jim Thompson


Yous guys should start circulating a claim among the audiophiles that
only amps and other audio electronics sound excellent if they were
designed and drafted with pencil and drafting board. Any audio
component won't have the right sound if it was designed with a lowly
computter program!

What do you mean start circulating a "claim", it's TRUE ;-)

...Jim Thompson
 
J

John Larkin

Jan 1, 1970
0
Jim said:
On Sun, 09 May 2004 09:56:37 -0700, John Larkin


On 8 May 2004 03:26:07 -0700, [email protected] (Johan
Wagener) wrote:


[snip]

This is for use in the leach amplifier.

Oh, audio. In that case, all rational design considerations are void.
File the corners off the packages or dip them in red wine or whatever
makes it sound best.

John


ROTFLMAO!

...Jim Thompson


Yous guys should start circulating a claim among the audiophiles that
only amps and other audio electronics sound excellent if they were
designed and drafted with pencil and drafting board. Any audio
component won't have the right sound if it was designed with a lowly
computter program!

What do you mean start circulating a "claim", it's TRUE ;-)

...Jim Thompson

The best audio interconnects are gold-plated, custom-bent hardline
coaxial cables with SMA connectors.

John
 
J

Jim Thompson

Jan 1, 1970
0
On Tue, 11 May 2004 08:04:08 -0700, John Larkin

[snip]
The best audio interconnects are gold-plated, custom-bent hardline
coaxial cables with SMA connectors.

John

Not necessarily so!

I had a fellow working for me that bought a Heapshit Preamp Kit many
years ago.

He didn't like the looks of the audio coax included with the kit, so
he substituted some nice ultra-small diameter teflon cable (shielded)
that we had in the lab.

Bye, bye, high frequency response.

...Jim Thompson
 
Top