On Fri, 17 Aug 2018 14:53:56 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
>On 17/08/2018 11:49, krw@notreal.com wrote:
>> On Thu, 16 Aug 2018 15:36:11 +1000, Chris Jones
>> <lugnut808@spam.yahoo.com> wrote:
>>
>>> On 16/08/2018 12:28, krw@notreal.com wrote:
>>>> On Wed, 15 Aug 2018 16:03:56 +1000, Chris Jones
>>>> <lugnut808@spam.yahoo.com> wrote:
>>>>
>>>>> On 15/08/2018 01:27, pcdhobbs@gmail.com wrote:
>>>>>> Both also obsolete. :(
>>>>>
>>>>> I object to that terminology.
>>>>>
>>>>> If a manufacturer is not capable of making, or unwilling to make, or too
>>>>> inept to sell, something as good as they used to make, that might make
>>>>> the manufacturer obsolete or incompetent or irrelevant, but in my book
>>>>> it makes the parts become merely unavailable, not obsolete.
>>>>
>>>> Nonsense. Perhaps it's no longer *profitable* to make?
>>>
>>> As I stated, I was objecting to the terminology. I was not speculating
>>> on the profitability of making the parts and selling them at any
>>> particular price.
>>
>> Price is only tangentially related to profit. If something isn't
>> making a profit, it's not going to get made. That's all there is to
>> it.
>>
>You're repeatedly trying to argue with me about something that I didn't
>discuss, that being the motivation (sensible or otherwise) for
>discontinuing a part.
But you are discussing it. You made the asinine statement that the
suppliers were, somehow, no longer capable of making these parts. My
answer is *bullshit*. They have no (insufficient) incentive to make
these parts. Now you claim you said nothing about profit. Whether
you like it or not, engineering is all about economics.
>
>I should spend my time on something else.
You're right. Engineering is *WAY* above your head.
Reply by ●August 17, 20182018-08-17
On Friday, August 17, 2018 at 6:29:12 PM UTC-4, dagmarg...@yahoo.com wrote:
> On Wednesday, August 8, 2018 at 7:59:30 PM UTC-4, Phil Hobbs wrote:
>
> >
> > The 2SD2704K is a superbeta NPN with a BV_EBO of 25V, which is great,
> > but there seems to be no PNP that gets anywhere close to that. I can
> > protect the PNPs with diodes, but that's inelegant--I'd much rather have
> > a PNP that can take 10V B-E.
> >
> > Any faves?
> >
> > Cheers
> >
> > Phil Hobbs
> >
> > --
> > Dr Philip C D Hobbs
> > Principal Consultant
> > ElectroOptical Innovations LLC / Hobbs ElectroOptics
> > Optics, Electro-optics, Photonics, Analog Electronics
> > Briarcliff Manor NY 10510
> >
> > http://electrooptical.net
> > http://hobbs-eo.com
>
> As long as I was BJT-hunting over at Diodes, I threw in a query aimed at
> your requirements--
>
> SOT-23, Vcbo 20V (min)
> https://www.diodes.com/assets/Datasheets/DSS5220T.pdf
>
> There are probably lots more; I just grabbed the first result that
> looked like a PNP lo-sat transistor.
>
> Oh, SCNR, here's another--
> SOT-23, Vcbo 80V (min)
> https://www.diodes.com/assets/Datasheets/ds31389.pdf
>
> That's batting two for two. I'll quit while I'm ahead.
>
> Cheers,
> James Arthur
Oops, sorry. Vebo is rotten for both--I got too excited and scanned the
wrong rows.
Cheers,
James
Reply by ●August 17, 20182018-08-17
On Wednesday, August 8, 2018 at 7:59:30 PM UTC-4, Phil Hobbs wrote:
>
> The 2SD2704K is a superbeta NPN with a BV_EBO of 25V, which is great,
> but there seems to be no PNP that gets anywhere close to that. I can
> protect the PNPs with diodes, but that's inelegant--I'd much rather have
> a PNP that can take 10V B-E.
>
> Any faves?
>
> Cheers
>
> Phil Hobbs
>
> --
> Dr Philip C D Hobbs
> Principal Consultant
> ElectroOptical Innovations LLC / Hobbs ElectroOptics
> Optics, Electro-optics, Photonics, Analog Electronics
> Briarcliff Manor NY 10510
>
> http://electrooptical.net
> http://hobbs-eo.com
As long as I was BJT-hunting over at Diodes, I threw in a query aimed at
your requirements--
SOT-23, Vcbo 20V (min)
https://www.diodes.com/assets/Datasheets/DSS5220T.pdf
There are probably lots more; I just grabbed the first result that
looked like a PNP lo-sat transistor.
Oh, SCNR, here's another--
SOT-23, Vcbo 80V (min)
https://www.diodes.com/assets/Datasheets/ds31389.pdf
That's batting two for two. I'll quit while I'm ahead.
Cheers,
James Arthur
Reply by ●August 17, 20182018-08-17
Octopart: "Your query, 2SA1613, matched zero parts."
Cheers
Phil Hobbs
Reply by Chris Jones●August 17, 20182018-08-17
On 17/08/2018 11:49, krw@notreal.com wrote:
> On Thu, 16 Aug 2018 15:36:11 +1000, Chris Jones
> <lugnut808@spam.yahoo.com> wrote:
>
>> On 16/08/2018 12:28, krw@notreal.com wrote:
>>> On Wed, 15 Aug 2018 16:03:56 +1000, Chris Jones
>>> <lugnut808@spam.yahoo.com> wrote:
>>>
>>>> On 15/08/2018 01:27, pcdhobbs@gmail.com wrote:
>>>>> Both also obsolete. :(
>>>>
>>>> I object to that terminology.
>>>>
>>>> If a manufacturer is not capable of making, or unwilling to make, or too
>>>> inept to sell, something as good as they used to make, that might make
>>>> the manufacturer obsolete or incompetent or irrelevant, but in my book
>>>> it makes the parts become merely unavailable, not obsolete.
>>>
>>> Nonsense. Perhaps it's no longer *profitable* to make?
>>
>> As I stated, I was objecting to the terminology. I was not speculating
>> on the profitability of making the parts and selling them at any
>> particular price.
>
> Price is only tangentially related to profit. If something isn't
> making a profit, it's not going to get made. That's all there is to
> it.
>
You're repeatedly trying to argue with me about something that I didn't
discuss, that being the motivation (sensible or otherwise) for
discontinuing a part.
I should spend my time on something else.
Plonk.
Reply by ●August 16, 20182018-08-16
On Thu, 16 Aug 2018 15:36:11 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
>On 16/08/2018 12:28, krw@notreal.com wrote:
>> On Wed, 15 Aug 2018 16:03:56 +1000, Chris Jones
>> <lugnut808@spam.yahoo.com> wrote:
>>
>>> On 15/08/2018 01:27, pcdhobbs@gmail.com wrote:
>>>> Both also obsolete. :(
>>>
>>> I object to that terminology.
>>>
>>> If a manufacturer is not capable of making, or unwilling to make, or too
>>> inept to sell, something as good as they used to make, that might make
>>> the manufacturer obsolete or incompetent or irrelevant, but in my book
>>> it makes the parts become merely unavailable, not obsolete.
>>
>> Nonsense. Perhaps it's no longer *profitable* to make?
>
>As I stated, I was objecting to the terminology. I was not speculating
>on the profitability of making the parts and selling them at any
>particular price.
Price is only tangentially related to profit. If something isn't
making a profit, it's not going to get made. That's all there is to
it.
Reply by legg●August 16, 20182018-08-16
On Tue, 14 Aug 2018 05:32:32 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
2SA1613
Reply by Chris Jones●August 16, 20182018-08-16
On 16/08/2018 12:28, krw@notreal.com wrote:
> On Wed, 15 Aug 2018 16:03:56 +1000, Chris Jones
> <lugnut808@spam.yahoo.com> wrote:
>
>> On 15/08/2018 01:27, pcdhobbs@gmail.com wrote:
>>> Both also obsolete. :(
>>
>> I object to that terminology.
>>
>> If a manufacturer is not capable of making, or unwilling to make, or too
>> inept to sell, something as good as they used to make, that might make
>> the manufacturer obsolete or incompetent or irrelevant, but in my book
>> it makes the parts become merely unavailable, not obsolete.
>
> Nonsense. Perhaps it's no longer *profitable* to make?
As I stated, I was objecting to the terminology. I was not speculating
on the profitability of making the parts and selling them at any
particular price.
Reply by ●August 15, 20182018-08-15
On Wed, 15 Aug 2018 16:03:56 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
>On 15/08/2018 01:27, pcdhobbs@gmail.com wrote:
>> Both also obsolete. :(
>
>I object to that terminology.
>
>If a manufacturer is not capable of making, or unwilling to make, or too
>inept to sell, something as good as they used to make, that might make
>the manufacturer obsolete or incompetent or irrelevant, but in my book
>it makes the parts become merely unavailable, not obsolete.
Nonsense. Perhaps it's no longer *profitable* to make?
>If they could make something better then the parts would be obsolete,
>but then we wouldn't be upset about it.
Reply by ●August 15, 20182018-08-15
On Wednesday, August 15, 2018 at 3:22:02 PM UTC-4, tabb...@gmail.com wrote:
> On Wednesday, 15 August 2018 11:25:10 UTC+1, pcdh...@gmail.com wrote:
> > > These transistor have high inverting gain, and
> > > are designed to be highly symmetrical, so you
> > > can exchange the emitter and collector almost
> > > without affect. That's why the Veb values are
> > > so high. And that's why Vce(sat) is so low,
> > > in the forward as well as the inverted modes.
> >
> > > There are many uses for transistors made this
> > > way, and with a reliable company like Central
> > > Semi, they should be here for the long term.
> >
> > The 2SD2704K is an NPN version of the same idea, and it sure is useful, I agree. I wouldn't have a big problem characterizing a low-sat transistor for inverted use at higher voltage, though I'd probably do a lifetime buy once the design was done.
> >
> > My trouble is that customers who are producing my designs tend to get queasy about exceeding Absolute Maximum limits from the datasheets.
>
> is it the only way?
Not at all--it just saves parts. Low-Z circuits have fewer options, but my PNP is the driver stage of a Sziklai pair so I can just use a 10k resistor and a diode from base to emitter to prevent reverse voltage. (For lurkers: a Sziklai is like a Darlington, but with a PNP driving an NPN, so that the whole thing looks like a single power PNP).
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510
http://electrooptical.nethttp://hobbs-eo.com