Transistor equivalent to UK's BC183B?

Hi all,
I am trying to rake together the components to build a metal detector.
The plans are from the UK, and I'm US. The plans call for BC183B
transistors, and I was wondering if there was an easier-to-get
equivalent. All the plan says is that equivalents will work, but it
must be a small-signal NPN transistor with a gain of at least +250.
Any easy-to-come-by equivalents?
Thanks,
Chloe H.

 

[Dave Platt]

In article <1168471434.408768.68130@p59g2000hsd.googlegroups.com>,
<hmz6@yahoo.com> wrote:

Hi all,
I am trying to rake together the components to build a metal detector.
The plans are from the UK, and I'm US. The plans call for BC183B
transistors, and I was wondering if there was an easier-to-get
equivalent. All the plan says is that equivalents will work, but it
must be a small-signal NPN transistor with a gain of at least +250.
Any easy-to-come-by equivalents?

The pages at DataSheetArchive.com suggest a BC239 or 2N5827 as being
similar.

DigiKey's catalog lists some ON Semiconductor TO-92 parts such as the
MPSA18 and BC546 and BC547 which may have sufficiently high minimum
gain. For example the BC546 lists minimum 150, typical 300, and an fT
similar to that of the BC183B. You might have to buy a few and
hand-select one with high enough gain, or you might get lucky right
out of the box. At under $2 for ten, you might as well stock up

--
Dave Platt <dplatt@radagast.org> AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

 

[Eeyore]

hmz6@yahoo.com wrote:

Hi all,
I am trying to rake together the components to build a metal detector.
The plans are from the UK, and I'm US. The plans call for BC183B
transistors, and I was wondering if there was an easier-to-get
equivalent. All the plan says is that equivalents will work, but it
must be a small-signal NPN transistor with a gain of at least +250.
Any easy-to-come-by equivalents?

Loads of them.

BC548B or C should be readily available.

Graham

 

Thanks,
Actually right now I have 5 transistors laying around, maybe I could
ask you if they will work, as I don't know much about them.

Two are marked C945
GR331

one is 1702L
PH 8 d

one is 1502C
PH 8 n

one is 1502C
PH 8 7


Sorry if this is a mess, but thanks!!
Chloe H.

 

[Dave Platt]

In article <1168646837.781607.16810@s34g2000cwa.googlegroups.com>,
<hmz6@yahoo.com> wrote:

Thanks,
Actually right now I have 5 transistors laying around, maybe I could
ask you if they will work, as I don't know much about them.

Two are marked C945
GR331

Probably a 2SC945, an NPN high-frequency oscillator. Voltage rating
seems high enough, fT seems plenty high. Gain might or might not be
high enough... one manufacturer's data sheet says gain minimum 70, max
700, while the NEC data sheet says that their parts are graded into
four different ranges (90-180, 135-270, 200-400, and 300-600).

It's probably worth a try.

With the leads pointed up and the flat side towards you, the leads
will be base/collector/emitter in that order.

one is 1702L
PH 8 d

one is 1502C
PH 8 n

one is 1502C
PH 8 7

Those are probably some company's "house numbers" rather than a
standard part number. You'd have to test 'em to figure out what they
are and how they behave.

--
Dave Platt <dplatt@radagast.org> AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

 

[Eeyore]

Dave Platt wrote:

hmz6@yahoo.com> wrote:
Thanks,
Actually right now I have 5 transistors laying around, maybe I could
ask you if they will work, as I don't know much about them.

Two are marked C945
GR331

Probably a 2SC945, an NPN high-frequency oscillator. Voltage rating
seems high enough, fT seems plenty high. Gain might or might not be
high enough... one manufacturer's data sheet says gain minimum 70, max
700, while the NEC data sheet says that their parts are graded into
four different ranges (90-180, 135-270, 200-400, and 300-600).

GR = the green gain grouping. Which one was that ?

Graham

 

[Eeyore]

Dave Platt wrote:

hmz6@yahoo.com> wrote:

one is 1702L
PH 8 d

one is 1502C
PH 8 n

one is 1502C
PH 8 7

Those are probably some company's "house numbers" rather than a
standard part number. You'd have to test 'em to figure out what they
are and how they behave.

I suspect they're SMT devices. PH = Philips. Very small SMT parts almost never
have the part number you'd expect. You need to know what it is to begin with to
decode it from the data sheet.

Graham

 

[Dave Platt]

In article <45A862FB.AA1A0F4D@hotmail.com>,
Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote:

Probably a 2SC945, an NPN high-frequency oscillator. Voltage rating
seems high enough, fT seems plenty high. Gain might or might not be
high enough... one manufacturer's data sheet says gain minimum 70, max
700, while the NEC data sheet says that their parts are graded into
four different ranges (90-180, 135-270, 200-400, and 300-600).

GR = the green gain grouping. Which one was that ?

The NEC data sheet lists them by letter-code - R, Q, P, and K, in the
order I gave the gains. Micro Electronics seems to have used the same
binning convention NEC did. Usha, in India, uses a slightly different
binning convention (R 40-80, O 70-140, Y 120-240, G 200-400, L
350-700). I don't see notations on any of the data sheets which would
indicate a color coding.

Using a transistor tester to figure out the hFE would probably be the
quickest way to figure out if this one transistor might work in the
metal detector circuit.

--
Dave Platt <dplatt@radagast.org> AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

 

[Eeyore]

Dave Platt wrote:

Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote:

Probably a 2SC945, an NPN high-frequency oscillator. Voltage rating
seems high enough, fT seems plenty high. Gain might or might not be
high enough... one manufacturer's data sheet says gain minimum 70, max
700, while the NEC data sheet says that their parts are graded into
four different ranges (90-180, 135-270, 200-400, and 300-600).

GR = the green gain grouping. Which one was that ?

The NEC data sheet lists them by letter-code - R, Q, P, and K, in the
order I gave the gains. Micro Electronics seems to have used the same
binning convention NEC did. Usha, in India, uses a slightly different
binning convention (R 40-80, O 70-140, Y 120-240, G 200-400, L
350-700). I don't see notations on any of the data sheets which would
indicate a color coding.

It's the Japanese norm. Red Orange Yellow Green and Blue come to mind. If it's
GR then it's fine.

Using a transistor tester to figure out the hFE would probably be the
quickest way to figure out if this one transistor might work in the
metal detector circuit.

Why not just buy a BC548B ( gain graded ) ? You can get those even in the USA !

Graham

 

[Mark Aitchison]

hmz6@yahoo.com wrote:

Hi all,
I am trying to rake together the components to build a metal detector.
The plans are from the UK, and I'm US. The plans call for BC183B
transistors, and I was wondering if there was an easier-to-get
equivalent.

The BC183 is a plain vanilla NPN silicon small-signal transistor (a bit
out of date, although I think I have one), and the "B" gain group is the
middle of the range gain (hFE 240-500 at 2mA Ic and Vce=5; typically
330). Not especially high voltage, not especially low noise. So quite a
few transistors should fit in there. Unfortunately, unless you have the
-A, -B and -C (or -16, -25 and -40) gain range specification, which many
Pro-Electron (BC... - most European small signal transistors) you may
have to go through transistors like PN100 or 2N3569 with a gain tester,
as others have suggested. The best idea is to hunt down something like
the BC549B (see below).

For what it's worth, the background to that family of transistors goes
something like this: the "BC" at the start identifies a silicon audio
transistor (using the Pro-electron naming scheme, which I think is more
helpful than JEDEC), and is reasonably easy to find explained on the
internet, but there isn't exactly a formal system to the number part...
what is NPN or PNP, for instance. But back around 1966 a family of
TO-18 silicon transistors came out, BC107 to BC109, that not only became
very popular, their number system became popular and so was copied by
many other transistors, up to the present day. This is how it works:
...7 means high voltage, ..9 means high/gain and low noise, and ..8 means
cheap - not especially great in any way. This was followed by BC177 to
BC179 for PNP counterparts. Then BC147-9 and BC157-9 for "lockfit"
plastic casing versions, and various other plastic case versions with
the middle digit EVEN for NPN and ODD for PNP. A lot (but beware: not
all) BC... transistors use the ..7/8/9 tradition, a common pinout that
goes e-b-c (dating back to the AC126 and OC71), and odd/even middle
digits indicating PNP/NPN... exceptions being ones like BC338, BC640,
etc. Standardisation is a wonderful thing in the electronics industry;
it is just a pity there are so many different standards to choose from!

An even more well-used tradition/standard is the gain group letters at
the end: A for low gain, B for middle gain, and C for high gain. While
the BC..7/8/9 family was becoming popular, Texas Instruments had
Pro-Electron transistors BC182/3/4 (NPN) and BC212/3/4 (PNP) with high
voltage/cheap/high gain signified by the last digit a bit like the 7/8/9
family. But they had letters like "L" at the end giving the pinout
(e.g. b-c-e), not the gain. Quite a few US manufacturers (including
Motorola) made transistors with Pro-Electron names, many making the
BC182/3/4 series. It is interesting to see them swing, over time, to
follow the -A/B/C suffix giving gain ranges (which is nice), while some
European brands eventually moved away from that to use -25, -40 etc to
show 250+ gain, 400+ gain, etc!

Back to the problem at hand: Many transistors popular in the US (e.g.
the 2N4124, and 2N930 - is that still popular?) *may* have the
appropriate gain, but they often lack the restricted gain range marking
that ensures a particular transistor will have enough gain. You may have
to try a few on an hFE tester to get one that is suitable. Or you could
try something like a 2N5088 and know you have enough gain, but it has
less current capability and base-emitter reverse voltage rating - which
might not matter in your circuit, but I cannot be sure. Some of the
good 2N.... equivalents, that are pretty likely to have a high enough
minimum gain, are somewhat rare (e.g. TO18 can). There is, however, a
really good answer...

The best idea, as Eeyore suggested, is to get one of those many
transistors like BC547B, BC549B, etc that have the gain range specified;
these are pretty common at mail-order parts suppliers like futurelec,
jaycar and digikey, and pretty much the transistor-of-choice for general
circuits from Australia to England so not likely to go obsolete any time
soon. But not everyone stocks the restricted gain range versions, or
specifies them in the catalogue (e.g. Jaycar simply says "BC549" but you
are likely to get BC549B). Shop around for a supplier that advertises a
BC549B or whatever - they are plentiful.

Other examples: BC109B, BC168B,BC169B,BC547B,BC548B,BC549B,BC546B, or
BC550B. The -C gain group is even better. If you have to get a BC54-
transistor without the gain group specified choose the BC..9 or BC550,
since they pretty much always don't include much below a gain of 250.

Mark A

 

[Eeyore]

Mark Aitchison wrote:

hmz6@yahoo.com wrote:
Hi all,
I am trying to rake together the components to build a metal detector.
The plans are from the UK, and I'm US. The plans call for BC183B
transistors, and I was wondering if there was an easier-to-get
equivalent.

The BC183 is a plain vanilla NPN silicon small-signal transistor (a bit
out of date, although I think I have one), and the "B" gain group is the
middle of the range gain (hFE 240-500 at 2mA Ic and Vce=5; typically
330). Not especially high voltage, not especially low noise. So quite a
few transistors should fit in there. Unfortunately, unless you have the
-A, -B and -C (or -16, -25 and -40) gain range specification, which many
Pro-Electron (BC... - most European small signal transistors) you may
have to go through transistors like PN100 or 2N3569 with a gain tester,
as others have suggested. The best idea is to hunt down something like
the BC549B (see below).

For what it's worth, the background to that family of transistors goes
something like this: the "BC" at the start identifies a silicon audio
transistor (using the Pro-electron naming scheme, which I think is more
helpful than JEDEC), and is reasonably easy to find explained on the
internet, but there isn't exactly a formal system to the number part...
what is NPN or PNP, for instance. But back around 1966 a family of
TO-18 silicon transistors came out, BC107 to BC109, that not only became
very popular, their number system became popular and so was copied by
many other transistors, up to the present day. This is how it works:
..7 means high voltage, ..9 means high/gain and low noise, and ..8 means
cheap - not especially great in any way. This was followed by BC177 to
BC179 for PNP counterparts. Then BC147-9 and BC157-9 for "lockfit"
plastic casing versions, and various other plastic case versions with
the middle digit EVEN for NPN and ODD for PNP. A lot (but beware: not
all) BC... transistors use the ..7/8/9 tradition, a common pinout that
goes e-b-c (dating back to the AC126 and OC71), and odd/even middle
digits indicating PNP/NPN... exceptions being ones like BC338, BC640,
etc. Standardisation is a wonderful thing in the electronics industry;
it is just a pity there are so many different standards to choose from!

The e-b-c pinout ( or c-b-e ) is for compatability with TO-18 devices which the
BC107/8/9 were.

Even today the BC547/8/9 are very popular modern equivalents together with the
pnp BC557/8/9 complements.

Beware that the BC182/3/4 and BC212/3/4 had an 'L' variant e.g. BC183L with a
b-c-e pinout like the popular JEDEC 2N3904.....family parts ( another series
that refuses to lay down and die ! ).

Graham

 

[Hal Murray]

Beware that the BC182/3/4 and BC212/3/4 had an 'L' variant e.g. BC183L with a
b-c-e pinout like the popular JEDEC 2N3904.....family parts ( another series
that refuses to lay down and die ! ).

Is "refuses to lay down and die" a derogatory term?

What do people keep in their junk box for misc transistors?

--
These are my opinions, not necessarily my employer's. I hate spam.

 

[Eeyore]

Hal Murray wrote:

Beware that the BC182/3/4 and BC212/3/4 had an 'L' variant e.g. BC183L with a
b-c-e pinout like the popular JEDEC 2N3904.....family parts ( another series
that refuses to lay down and die ! ).

Is "refuses to lay down and die" a derogatory term?

Not at all.

Graham

 

[Mark Aitchison]

Hal Murray wrote:

... What do people keep in their junk box for misc transistors?

BC549, BC556 and some of that family, plus 2N2222A, PN100/200, and
MPF102 (used MPF102s for all sorts of things, for years, but starting to
think I should use a different/cheaper JFET), plus whatever power
transistors I have left over/pulled out (mostly plastic equivs of
2N3055/MJ2955 and various little fellas like MJE340 or BD639 that change
all the time - no particular favourites for power transistors, just
whatever will do).

I also have an assortment of static-sensitive devices like the 2N7000
and IRFP460 that aren't in my junk box, which I don't tend to use as
much as I should, now I come to think about it... perhaps out of sight,
out of mind.

I tend to use cheap quad opamps instead of transistors nowadays, even
when a transistor would be fine. Although I've used microprocessors
since 1978 I've managed to resist the temptation to use them all the
time when a few transistors or opamps could do the job.

Mark A

 

[Homer J Simpson]

"Hal Murray" <hal-usenet@ip-64-139-1-69.sjc.megapath.net> wrote in message
news:Y-6dnSkgUe7AO1PYnZ2dnUVZ_tHinZ2d@megapath.net...

Is "refuses to lay down and die" a derogatory term?

"It's Toyota when your motor keeps on running"