I have a Kenmore induction cooktop that is about 18 years old, OEM from
Sanyo. Some of the power transistors are blown. The only marking is
T30G40. I _think_ the package is TO3PL but I could be wrong. A simple
google search turns up specs like 400v 30a 300w and 1000v 30a 350w.

Could someone please find a cross reference to a part I can actually
buy.

thanks,

.... jeff

On 1 Jul 2005 15:46:27 -0700, put finger to
keyboard and composed:

I have a Kenmore induction cooktop that is about 18 years old, OEM from
Sanyo. Some of the power transistors are blown. The only marking is
T30G40.

FWIW, I'm guessing the transistor is a Shindengen part.


- Franc Zabkar
--
Please remove one 's' from my address when replying by email.

I also have a Kenmore induction cooktop that has bad T30G40
transistors. Has anyone found where to buy them? I need ten in case
someone wants to put a large order to a distributor, and offer to
resell them to end users like me.

Raymond

On 12 Sep 2005 17:05:54 GMT,
lid (Raymondj) put finger
to keyboard and composed:

I also have a Kenmore induction cooktop that has bad T30G40
transistors. Has anyone found where to buy them? I need ten in case
someone wants to put a large order to a distributor, and offer to
resell them to end users like me.

Raymond

Here are the specs:
http://www.datasheetarchive.com/semi...csheet=2032248

Part Number = T30G40
Description = Si NPN Power Bipolar Junction Transistor
Manufacturer = Shindengen
V(BR)CEO (V) = 400
V(BR)CBO (V) = 800
I(C) Abs.(A) Collector Current = 30
Absolute Max. Power Diss. (W) = 200
h(FE) Min. Static Current Gain = 80
f(T) Min. (Hz) Transition Freq = 7.0M
t(d) Max. (s) Delay time. = 3.0u
t(s) Max. (s) Storage time. = 3.0u
t(f) Max. (s) Fall time. = 1.0u
Package = SIP
Military = N

B&D Enterprises (http://www.bdent.com/distributors/shindingen.jsp)
is/was a Shindengen distributor, but this part is not listed on their
site. They may still be worth a try, though.

-- Franc Zabkar

Please remove one 'i' from my address when replying by email.

"kaplanB" wrote in message
roups.com...
Jeff,
Did you ever find a supplier or cross reference for T30G40?

I'm on the hunt as well

Thanks,
..Kap


Have you ever thought about entering T30G40 into a Google search?

Google quickly found: 800V Vcbo, 30A Ic Low frequency power silicon
NPN transistor Operational temperature range from 0°C to 150°C.

V(BR)CEO (V)=400
V(BR)CBO (V)=800
I(C) Abs.(A) Collector Current=30
Absolute Max. Power Diss. (W)=200
h(FE) Min. Static Current Gain=80
f(T) Min. (Hz) Transition Freq=7.0M
t(d) Max. (s) Delay time.=3.0u
t(s) Max. (s) Storage time.=3.0u
t(f) Max. (s) Fall time.=1.0u
Package=SIP
Military=N

As much as I hate gmail and GoogleGroups, Google itself is quite handy!

73, Dr. Barry L. Ornitz WA4VZQ

On 4/17/2011 3:31 PM Barry spake thus:

"kaplanB" wrote in message
roups.com...

Jeff, Did you ever find a supplier or cross reference for T30G40?

I'm on the hunt as well

Have you ever thought about entering T30G40 into a Google search?

Google quickly found: 800V Vcbo, 30A Ic Low frequency power silicon
NPN transistor Operational temperature range from 0°C to 150°C.

V(BR)CEO (V)=400
V(BR)CBO (V)=800
I(C) Abs.(A) Collector Current=30
Absolute Max. Power Diss. (W)=200
h(FE) Min. Static Current Gain=80
f(T) Min. (Hz) Transition Freq=7.0M
t(d) Max. (s) Delay time.=3.0u
t(s) Max. (s) Storage time.=3.0u
t(f) Max. (s) Fall time.=1.0u
Package=SIP
Military=N

As much as I hate gmail and GoogleGroups, Google itself is quite handy!

With all due respect, since often people don't make even the minimal
effort to find something by "Googling" (gawd, how I hate that that's now
a verb!), you didn't find what was being asked for here. Which was a
cross-reference or substitution guide for this device, not a definition
of its parameters.

I find this is true with a lot of semiconductors and other things out
the it's fairly easy to find datasheets and technical details such as
you put up there, but often difficult or impossible to come up with a
simple answer to "what other devices can I substitute for this one,
since there's no way in hell I'll ever be able to obtain one of these?".

(Of course, you can always find another device that matches these
parameters, but that's not a trivial exercise, unless one has some handy
references available. One *might* be able to do this using DigiKey's
parameter-matching item search, but I couldn't say for sure, not having
looked up transistors using it.)


--
The current state of literacy in our advanced civilization:

yo
wassup
nuttin
wan2 hang
k
where
here
k
l8tr
by

- from Usenet (what's *that*?)

"David Nebenzahl" wrote in message
s.com...
On 4/17/2011 3:31 PM Barry spake thus:

"kaplanB" wrote in message
roups.com...

Jeff, Did you ever find a supplier or cross reference for T30G40?

I'm on the hunt as well

Have you ever thought about entering T30G40 into a Google search?

Google quickly found: 800V Vcbo, 30A Ic Low frequency power silicon
NPN transistor Operational temperature range from 0°C to 150°C.

V(BR)CEO (V)=400
V(BR)CBO (V)=800
I(C) Abs.(A) Collector Current=30
Absolute Max. Power Diss. (W)=200
h(FE) Min. Static Current Gain=80
f(T) Min. (Hz) Transition Freq=7.0M
t(d) Max. (s) Delay time.=3.0u
t(s) Max. (s) Storage time.=3.0u
t(f) Max. (s) Fall time.=1.0u
Package=SIP
Military=N

As much as I hate gmail and GoogleGroups, Google itself is quite
handy!

With all due respect, since often people don't make even the minimal
effort to find something by "Googling" (gawd, how I hate that that's
now a verb!), you didn't find what was being asked for here. Which was
a cross-reference or substitution guide for this device, not a
definition of its parameters.

I find this is true with a lot of semiconductors and other things out
the it's fairly easy to find datasheets and technical details such
as you put up there, but often difficult or impossible to come up with
a simple answer to "what other devices can I substitute for this one,
since there's no way in hell I'll ever be able to obtain one of
these?".

(Of course, you can always find another device that matches these
parameters, but that's not a trivial exercise, unless one has some
handy references available. One *might* be able to do this using
DigiKey's parameter-matching item search, but I couldn't say for sure,
not having looked up transistors using it.)


--
The current state of literacy in our advanced civilization:

yo
wassup
nuttin
wan2 hang
k
where
here
k
l8tr
by

- from Usenet (what's *that*?)


To someone who understands these specs, and knows which ones are critical
to the application, this is all that is needed. To someone who wants to
buy a NTE "drop-in" part, I suggest you go to one of the Asian parts
suppliers who advertise that they can get the original part.

I found a part rated at 1000 BVces, 450 BVceo, 30 amps, and 250 watts.
It has a f(sub)T of 10 MHz and a Vce(sat) of 2 volts at 20 amps.
Now YOU tell me if this will work or not... Both Mouser and Digi-Key
found this part.

Barry WA4VZQ

On Sun, 17 Apr 2011 21:04:28 -0400, "Barry" wrote:

Welcome back. You were missed.

To someone who understands these specs, and knows which ones are critical
to the application, this is all that is needed. To someone who wants to
buy a NTE "drop-in" part, I suggest you go to one of the Asian parts
suppliers who advertise that they can get the original part.

NTE does not list a substitute. I've dealt with some of the "obsolete
parts" vendors. Figure on about a $200 minimum, whether you want 1
part or 100 parts. When I once absolutely had to buy from one of
these vendors, the negotiation to delivery ordeal took about 4 weeks.

I found a part rated at 1000 BVces, 450 BVceo, 30 amps, and 250 watts.
It has a f(sub)T of 10 MHz and a Vce(sat) of 2 volts at 20 amps.
Now YOU tell me if this will work or not... Both Mouser and Digi-Key
found this part.
Barry WA4VZQ

I thought this was going to be easy. I was wrong.

From the original data sheet at:
http://www.datasheets.org.uk/T30G40*-datasheet.html
With a saturation voltage of 2V at 30A, it's certainly an IGBT. Lots
to chose from on Digikey, but not in the package shown. I'll guess
the package is a TO-264 or TO-3PL
www.fairchildsemi.com/products/discrete/pdf/to264.pdf
I couldn't find a close match with the correct package on Digikey or
Mouser. All the TO-264 package devices are higher power, with higher
saturation voltages. Some compromises will need to be made here.

For those that have never used the Digikey parts search, it's best to
explain how to use it by example. Start here for discrete IGBT's.
http://search.digikey.com/scripts/DkSearch/dksus.dll?Cat=1376382&k=igbt
Under "Package", highlight "TO-264".
Hit the "Apply Filters" and notice how the choices are reduced.
Notice that under "Ic Max", there's no choice for "30A". Pick "40A"
and again hit "Apply Filters". You should see 2 devices listed,
neither of which is suitable. Try some of the other TO-264 package
variations for more trial and error. Eventually, it finds:
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=IXSK40N60BD1-ND
in a TO-264AA package, which is not an exact substitute, but might
work. Someone please check my guesswork. If you look at the data
sheet, it shows a gate instead of a base lead, but if you read the
fine print, it's really an IGBT, and not a FET.







--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

"Jeff Liebermann" wrote in message
...
On Sun, 17 Apr 2011 21:04:28 -0400, "Barry" wrote:

Welcome back. You were missed.

Thanks, Jeff

To someone who understands these specs, and knows which ones are
critical
to the application, this is all that is needed. To someone who wants
to
buy a NTE "drop-in" part, I suggest you go to one of the Asian parts
suppliers who advertise that they can get the original part.

NTE does not list a substitute. I've dealt with some of the "obsolete
parts" vendors. Figure on about a $200 minimum, whether you want 1
part or 100 parts. When I once absolutely had to buy from one of
these vendors, the negotiation to delivery ordeal took about 4 weeks.

I found a part rated at 1000 BVces, 450 BVceo, 30 amps, and 250 watts.
It has a f(sub)T of 10 MHz and a Vce(sat) of 2 volts at 20 amps.
Now YOU tell me if this will work or not... Both Mouser and Digi-Key
found this part.
Barry WA4VZQ

To begin, it is really a conventional NPN, not an IGBT. You have to
learn
that Digi-Key and Mouser are not perfect in their searches. I had to
relax
the specs to find the part - like using 20 amps rather than 30. However
when I checked the datasheet, the part was really rated at 30 amps. Go
figure...

I thought this was going to be easy. I was wrong.

From the original data sheet at:
http://www.datasheets.org.uk/T30G40*-datasheet.html
With a saturation voltage of 2V at 30A, it's certainly an IGBT.

Look at the very high base current. This is how the low Vce(sat) is
obtained. Also note the Vbe(sat).

Lots to chose from on Digikey, but not in the package shown. I'll guess
the package is a TO-264 or TO-3PL

It's a TO-247 case. Actually starting the search with the package style,
in my opinion, is a poor place to start. You need to match the critical
specs first. In this case, high breakdown voltage, high current, and low
saturation voltage were the critical specs to match first.

www.fairchildsemi.com/products/discrete/pdf/to264.pdf
I couldn't find a close match with the correct package on Digikey or
Mouser. All the TO-264 package devices are higher power, with higher
saturation voltages. Some compromises will need to be made here.

To avoid all the suspense, look at an OnSemi MJW18020. OnSemi even
has Spice2, PSpice, and Spice3 models as well as a Saber model for it.
While Digi-Key does not stock them, Mouser has them at less than $6 a
pop.

For those that have never used the Digikey parts search, it's best to
explain how to use it by example. Start here for discrete IGBT's.
http://search.digikey.com/scripts/DkSearch/dksus.dll?Cat=1376382&k=igbt
Under "Package", highlight "TO-264".
Hit the "Apply Filters" and notice how the choices are reduced.
Notice that under "Ic Max", there's no choice for "30A". Pick "40A"
and again hit "Apply Filters". You should see 2 devices listed,
neither of which is suitable. Try some of the other TO-264 package
variations for more trial and error. Eventually, it finds:
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=IXSK40N60BD1-ND
in a TO-264AA package, which is not an exact substitute, but might
work. Someone please check my guesswork. If you look at the data
sheet, it shows a gate instead of a base lead, but if you read the
fine print, it's really an IGBT, and not a FET.
--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

I know we are dating ourselves here, Jeff, but bipolar transistors are
much like vacuum tubes in that triodes are triodes and with some
changes in circuit values (and rewiring, of course) just about any triode
can be made to work in a pinch. Actually bipolar transistors generally
are even easier to substitute than vacuum tubes.

Do you have an NTE replacement book handy? Notice how many
transistors can be replaced by the NTE123AP. Look up the specs on
a 2N3904. The 2N3904 is far cheaper ($0.07) than the NTE part and can
probably be used anywhere the NTE123AP ($1.25) can be used.

73, Barry WA4VZQ

One other thing when using the Digi-Key or Mouser search engines...
If you need a part with, say, a BVceo of 100 volts or more, you can
highlight 100, 150, 200, and 250 volts at the same time. ?This will
usually speed up the search. I do like Mouser's engine in that it
immediately tells you that no part is available with that specification,
while Digi-Key waits until you do the filtering - not knowing which
spec cannot be met.

On Mon, 18 Apr 2011 23:43:35 -0400, "Barry" wrote:

To begin, it is really a conventional NPN, not an IGBT.

I'm not sure. Getting a Vce(sat) of 2V at 30A is a difficult feat
with most conventional NPN xsistors. Low saturation voltage is the
major benefit of IGBT. However, the original data sheet specifies the
device beta, which is not normally specified with an IGBT, which acts
more like a MOSFET.

You have to learn that Digi-Key and Mouser are not perfect in their
searches. I had to relax the specs to find the part - like using
20 amps rather than 30. However when I checked the datasheet, the
part was really rated at 30 amps. Go figure...

Data entry error? I rarely have to lookup anything by specifications
so the problem is fairly new to me. Usually, I just lookup the part
number, and dig through the mess of package mutations. I haven't
found too many errors.

From the original data sheet at:
http://www.datasheets.org.uk/T30G40*-datasheet.html
With a saturation voltage of 2V at 30A, it's certainly an IGBT.

Look at the very high base current. This is how the low Vce(sat) is
obtained. Also note the Vbe(sat).

Ib = 5Amps and Vbe(sat) = 2.5V. Now, I'm sure it's an IGBT. Such a
high base voltage and current is a characteristic of IGBT devices. See
typical curves at:
http://en.wikipedia.org/wiki/File:IvsV_IGBT.png
If it were an NPN transistor, the curves would be compressed around
Vbe(sat) = 0.7v to 1.0v (or slightly more if it has emitter current
balancing resistors inside) and have an upward slope.

I'm still undecided if it's an IGBT or a common xsistor, but I'm
begining to agree with you.

I'll guess the package is a TO-264 or TO-3PL

It's a TO-247 case.

I beg to differ (again). The original T30G40 data sheet shows the
package as 20.5 x 26.5 mm with a 3.3mm hole. The TO-247 package is
16.0 x 21 mm with a 3.0mm hole. The TO-264 is 20 x 20 mm with a 3.3mm
hole. Neither is a perfect match, but methinks the TO-264 is closer,
especially due to having the same larger hole size.
http://www.fairchildsemi.com/products/discrete/pdf/to247pdd_dim.pdf
http://www.fairchildsemi.com/products/discrete/pdf/to264.pdf

Actually starting the search with the package style,
in my opinion, is a poor place to start.

I beg to differ (yet again). Finding a suitable replacement that
doesn't fit in whatever is being repaired is rather useless. By
reducing the search to only those items that can actually be used as a
physical substitute, the search scope is drastically reduced.

You need to match the critical
specs first. In this case, high breakdown voltage, high current, and low
saturation voltage were the critical specs to match first.

I went for package, Vceo(max), Vce(sat), Ic(max), and Pt(max) in that
order.

To avoid all the suspense, look at an OnSemi MJW18020. OnSemi even
has Spice2, PSpice, and Spice3 models as well as a Saber model for it.
While Digi-Key does not stock them, Mouser has them at less than $6 a
pop.

http://www.onsemi.com/pub_link/Collateral/MJW18020-D.PDF
Nope. Other then my objection to the package (hole too small), the
beta is too low. The original has a minimum beta of 80, while this
xsistor shows a minimum of 5.5 at 20A.

Unfortunately, the device I excavated doesn't specify the beta.
http://ixdev.ixys.com/DataSheet/98573.pdf
Argh!

I know we are dating ourselves here, Jeff, but bipolar transistors are
much like vacuum tubes in that triodes are triodes and with some
changes in circuit values (and rewiring, of course) just about any triode
can be made to work in a pinch. Actually bipolar transistors generally
are even easier to substitute than vacuum tubes.

I like to think of FET's as a solid state analogue to vacuum tubes. I
was in college when the transition from tube to semiconductors was
taught. Over the 6 years of various skools, I started with tubes,
delved into bipolar, and graduated with FET's. Keeping them untangles
was not a trivial exercise, but I'm comfortable working in all three
areas.

Do you have an NTE replacement book handy?

Books? They tend to obsolete as soon as they're printed. I prefer
online lookups.
http://www.nteinc.com

Notice how many
transistors can be replaced by the NTE123AP.

http://www.nteinc.com/specs/100to199/pdf/nte123ap.pdf
The online lookup doesn't have a reverse NTE - JEDEC lookup so I
can't check how many the devices the NTE123AP replaces.

Look up the specs on
a 2N3904. The 2N3904 is far cheaper ($0.07) than the NTE part and can
probably be used anywhere the NTE123AP ($1.25) can be used.

Sure. The NTE123AP is probably a relabeled 2N3904 or 2N2222, both
very common parts. You're also paying for handling, bubble packaging,
cataloging, distribution, and retail floor space for the NTE part. The
2N3904 part is sold by the thousands, while NTE parts tend to be sold
one at a time. Of course the NTE parts are more expensive.

One other thing when using the Digi-Key or Mouser search engines...
If you need a part with, say, a BVceo of 100 volts or more, you can
highlight 100, 150, 200, and 250 volts at the same time.

Oops. I never noticed that you can select more than one. Thanks.



--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

"Jeff Liebermann" wrote in message
...
On Mon, 18 Apr 2011 23:43:35 -0400, "Barry" wrote:

To begin, it is really a conventional NPN, not an IGBT.

I'm not sure. Getting a Vce(sat) of 2V at 30A is a difficult feat
with most conventional NPN xsistors. Low saturation voltage is the
major benefit of IGBT. However, the original data sheet specifies the
device beta, which is not normally specified with an IGBT, which acts
more like a MOSFET.

From the original data sheet at:
http://www.datasheets.org.uk/T30G40*-datasheet.html
With a saturation voltage of 2V at 30A, it's certainly an IGBT.

Look at the very high base current. This is how the low Vce(sat) is
obtained. Also note the Vbe(sat).

Ib = 5Amps and Vbe(sat) = 2.5V. Now, I'm sure it's an IGBT. Such a
high base voltage and current is a characteristic of IGBT devices. See
typical curves at:
http://en.wikipedia.org/wiki/File:IvsV_IGBT.png
If it were an NPN transistor, the curves would be compressed around
Vbe(sat) = 0.7v to 1.0v (or slightly more if it has emitter current
balancing resistors inside) and have an upward slope.

Much beyond a volt or so, the curves should be linear, i.e. the Shockley
relationship becomes dominated by a pure resistance. I would expect the
device has multiple emitter balancing resistors to keep a hot spot from
forming at high currents.

I'm still undecided if it's an IGBT or a common xsistor, but I'm
begining to agree with you.

I'll guess the package is a TO-264 or TO-3PL

It's a TO-247 case.

I beg to differ (again). The original T30G40 data sheet shows the
package as 20.5 x 26.5 mm with a 3.3mm hole. The TO-247 package is
16.0 x 21 mm with a 3.0mm hole. The TO-264 is 20 x 20 mm with a 3.3mm
hole. Neither is a perfect match, but methinks the TO-264 is closer,
especially due to having the same larger hole size.
http://www.fairchildsemi.com/products/discrete/pdf/to247pdd_dim.pdf
http://www.fairchildsemi.com/products/discrete/pdf/to264.pdf

My bad. I only looked at the lead spacing. With an obsolete part with
unusual specs, matching the case is just icing on the cake. Matching the
electrical specs is usually difficult enough.

Actually starting the search with the package style,
in my opinion, is a poor place to start.

I beg to differ (yet again). Finding a suitable replacement that
doesn't fit in whatever is being repaired is rather useless. By
reducing the search to only those items that can actually be used as a
physical substitute, the search scope is drastically reduced.

You need to match the critical
specs first. In this case, high breakdown voltage, high current, and
low
saturation voltage were the critical specs to match first.

I went for package, Vceo(max), Vce(sat), Ic(max), and Pt(max) in that
order.

I chose Vceo, Ic, Pt, and Vce(sat) and left the case as "icing."
Mounting arrangements can be modified, but you cannot change the
electrical specs.

To avoid all the suspense, look at an OnSemi MJW18020. OnSemi even
has Spice2, PSpice, and Spice3 models as well as a Saber model for it.
While Digi-Key does not stock them, Mouser has them at less than $6 a
pop.

http://www.onsemi.com/pub_link/Collateral/MJW18020-D.PDF
Nope. Other then my objection to the package (hole too small), the
beta is too low. The original has a minimum beta of 80, while this
xsistor shows a minimum of 5.5 at 20A.

Unfortunately the Shindengen device does not list the conditions at which
hFE is measured. The application is an induction heater so hfe (ac) is
more important than hFE (DC). The higher fT of the OnSemi device
suggests that the hfe falls off less rapidly than in the Shindengen
device. With most induction heaters relying on self-excited power
oscillators, the actual hFE should not be that important. Do you
remember in the early days of transistors the exceptionally wide Beta
spreads of a given device? We, as engineers, learned to design circuits
that were not sensitive to Beta spread. Of course my experience is with
BIG vacuum tube dielectric heaters. [Need any NOS 3CX10000A3's?]

Unfortunately, the device I excavated doesn't specify the beta.
http://ixdev.ixys.com/DataSheet/98573.pdf
Argh!

The IGBT is a voltage driven device and the gate only draws current due
to its capacitance, so Beta is a meaningless term with an IGBT. Instead
you use gfs measured in amps/volt (much like gm in a pentode tube).

I know we are dating ourselves here, Jeff, but bipolar transistors are
much like vacuum tubes in that triodes are triodes and with some
changes in circuit values (and rewiring, of course) just about any
triode
can be made to work in a pinch. Actually bipolar transistors generally
are even easier to substitute than vacuum tubes.

I like to think of FET's as a solid state analogue to vacuum tubes. I
was in college when the transition from tube to semiconductors was
taught. Over the 6 years of various skools, I started with tubes,
delved into bipolar, and graduated with FET's. Keeping them untangles
was not a trivial exercise, but I'm comfortable working in all three
areas.

In my case both vacuum tubes and bipolar transistors were taught as an
undergraduate. By graduate school, tubes were dropped and field effect
devices were added. The nice thing about tubes was the fact that they
were usually forgiving of short term mistakes! :-) And then there is
the built-in pilot light!

Do you have an NTE replacement book handy?

Books? They tend to obsolete as soon as they're printed. I prefer
online lookups.
http://www.nteinc.com

Notice how many
transistors can be replaced by the NTE123AP.

http://www.nteinc.com/specs/100to199/pdf/nte123ap.pdf
The online lookup doesn't have a reverse NTE - JEDEC lookup so I
can't check how many the devices the NTE123AP replaces.

I quit counting after I found several hundred devices in the first few
pages. My point is that a small signal NPN will generally substitute for
most other small signal NPN's.

Look up the specs on
a 2N3904. The 2N3904 is far cheaper ($0.07) than the NTE part and can
probably be used anywhere the NTE123AP ($1.25) can be used.

Sure. The NTE123AP is probably a relabeled 2N3904 or 2N2222, both
very common parts. You're also paying for handling, bubble packaging,
cataloging, distribution, and retail floor space for the NTE part. The
2N3904 part is sold by the thousands, while NTE parts tend to be sold
one at a time. Of course the NTE parts are more expensive.

But if you have a 2N3904, or a 2N706, or even a PN2222, why bother to
order the NTE123AP? My point is that unless the circuit is unusual, it
will probably work fine with what you might have on hand.

One other thing when using the Digi-Key or Mouser search engines...
If you need a part with, say, a BVceo of 100 volts or more, you can
highlight 100, 150, 200, and 250 volts at the same time.

Oops. I never noticed that you can select more than one. Thanks.
--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Tomorrow I am off to visit WA5KSC, who I knew in high school, to
troubleshoot an old Heath Marauder (HX-10). After high school, we went
off to different colleges and lost touch. We reconnected after 45 years.
We were best friends then and we are best friends again now. That is one
of the nice things about ham radio. And working on old vacuum tube gear
is still fun!

73, Barry WA4VZQ

kaplanB wrote:
kaplanB had written this in response to
http://www.electrondepot.com/repair/...ce-126006-.htm

I reenter the discussion with a bit of trepidation as I'm am just a
pastor trying to fix his cooktop, not an
electrical engineer.

I have learned a LOT from your posts and this adventure. I think I
have learned enough to say that what
I'm trying to find a substitute for (Shindengen T30G40) is not an
IGBT or a NPN. It is a PNP! My thinking
is based on three main factors.

I've drawn my own schematic and the cooktop (Kenmore 564.4498512)
seems to look like a "quasi-
resonant" circuit I found when researching induction cooktop designs.
These designs use PNP transistor.

Second, the voltage at the base, measured on a working element, is
-56 Vdc when idle and -60 Vdc
when energized. Doesn't' that "turn on" a PNP transistor?

Not necessarily... You have to measure the base voltage in respect to the
emitter. Assuming that it's a silicon device, you should see -0.65V
to -0.8V at the base with respect to the emitter. That will turn a PNP
transistor on. If the difference in voltage between base and emitter less
than 0.65V, then the transistor isn't on.


Third, pulled the transistors off the board and one of the three power
transistors tests OK as a PNP.

Questionable assumption... How do you know the others are PNP units? Do
they have the same part numbers?


Kap B


Here's a quick spec on the T30G40 transistor:

Si NPN Power BJT
Shindengen Electric Mfg. Co., Ltd.
V(BR)CEO (V)=400
V(BR)CBO (V)=800
I(C) Abs.(A) Collector Current=30
Absolute Max. Power Diss. (W)=200
h(FE) Min. Static Current Gain=80
f(T) Min. (Hz) Transition Freq=7.0M
t(d) Max. (s) Delay time.=3.0u
t(s) Max. (s) Storage time.=3.0u
t(f) Max. (s) Fall time.=1.0u
Package=SIP
Military=N

That indicates that it's an NPN unit; not PNP. Are you sure that you're
testing the transistors correctly? Maybe you should post a quick narrative
on how you're trying to troubleshoot. And be careful that you know the
polarity of the test leads of the ohms function of your multimeter... A few
will fool you.

--
David
dgminala at mediacombb dot net