> On Fri, 15 Oct 2021 11:21:24 -0700 (PDT), Rich S
> <richsulinengineer@gmail.com> wrote:
>
>> On Friday, October 15, 2021 at 6:01:14 PM UTC, John Larkin wrote:
>>> https://www.digikey.com/en/products/detail/microchip-technology/JANS1N4102DUR-1-TR/13995295
>>>
>>> Somebody must buy them.
>>>
>>> --
>>>
>>> If a man will begin with certainties, he shall end with doubts,
>>> but if he will be content to begin with doubts he shall end in certainties.
>>> Francis Bacon
>>
>> Avalanche 8.7 volts, seems odd, probably associated with a one design or
>> application. (input clamp?).
>> Must be some extant military gear with support contract, keeping the
>> (sub)contractor in business.
>> $140 for a mil-spec part,.. I dunno, haven't kept up on these, but honestly isn't
>> a surprise to me...
>>
>> =RS
>
> I need an 8.7 v 2% zener as a clamp, to protect a $300 distributed amp
> chip rated for 9 volts abs max. Parts are hard to get lately.
>
> I'll go for 5% and pray.
>
Did a little re-engineering, and see that the apparent power and size
requirements of your zener look do-able while retaining the majority of
the Codatron(R) specifications (on and off datasheet).
Biggie: noise. Guarantee no avalanche type noise or oscillation from
zero current to 500uA thru the Codatron(R) module.
That current gets "amplified" by your choice of the current pass
transistor which adds its Vbe to the total zener voltage.
The module is connected from the base of your NPN current pass
transistor to its collector; zener use from emitter to collector.
Size of the Codatron(R) module? Perhaps SOT363.
Size of your NPN current pass transistor? Up to you.
Thanks,
R. Baer
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Reply by legg●October 16, 20212021-10-16
On Fri, 15 Oct 2021 11:01:04 -0700, John Larkin
<jlarkin@highland_atwork_technology.com> wrote:
Microchip must have bought a business with a warehouse bin full of
them - and digikey just auto-transfered their stock list.
Aren't robots fun ?
Welcome. Let me take your hat.
RL
Reply by ●October 16, 20212021-10-16
On Fri, 15 Oct 2021 23:57:46 -0700, Robert Baer
<robertbaer@localnet.com> wrote:
JAN is a military screened/qualified part. No wonder a fighter costs
hundreds of millions each.
--
Father Brown's figure remained quite dark and still;
but in that instant he had lost his head. His head was
always most valuable when he had lost it.
Reply by ●October 16, 20212021-10-16
On Sat, 16 Oct 2021 00:29:50 -0700, Robert Baer
<robertbaer@localnet.com> wrote:
>John Larkin wrote:
>> On Fri, 15 Oct 2021 11:21:24 -0700 (PDT), Rich S
>> <richsulinengineer@gmail.com> wrote:
>>
>>> On Friday, October 15, 2021 at 6:01:14 PM UTC, John Larkin wrote:
>>>> https://www.digikey.com/en/products/detail/microchip-technology/JANS1N4102DUR-1-TR/13995295
>>>>
>>>> Somebody must buy them.
>>>>
>>>> --
>>>>
>>>> If a man will begin with certainties, he shall end with doubts,
>>>> but if he will be content to begin with doubts he shall end in certainties.
>>>> Francis Bacon
>>>
>>> Avalanche 8.7 volts, seems odd, probably associated with a one design or
>>> application. (input clamp?).
>>> Must be some extant military gear with support contract, keeping the
>>> (sub)contractor in business.
>>> $140 for a mil-spec part,.. I dunno, haven't kept up on these, but honestly isn't
>>> a surprise to me...
>>>
>>> =RS
>>
>> I need an 8.7 v 2% zener as a clamp, to protect a $300 distributed amp
>> chip rated for 9 volts abs max. Parts are hard to get lately.
>>
>> I'll go for 5% and pray.
>>
> Would about 8.22V 1% do? Low power part as spec is 100uA nominal
>500uA max (to 200C).
> Fudge by adding a diode in series, which can be thermally coupled,
>time constant maybe 10mSec worst case.
>
> Thanks, R.Baer
The HMC659 output is rated 9 volts abs max. ADI says to take this very
seriously, but they would. So I have a 1 pF schottky clamp diode (even
that 1 pF is annoying) and then the biased-up bypassed 8.7v zener. It
might have to dump 50 mA.
I'd test the amp chip for actual breakdown, but we only have one in
stock now and they cost $330 each.
This is nominally an RF part, so it's likely it will really swing to
at least 2x Vcc. That's something the RF boys tend to do, specify max
supply voltage and not max device voltage. I'll eventually try it and
maybe delete the clamp.
I want all the swing I can get, but we only need to bias it high and
pulse it in the down direction.
--
Father Brown's figure remained quite dark and still;
but in that instant he had lost his head. His head was
always most valuable when he had lost it.
Reply by Robert Baer●October 16, 20212021-10-16
John Larkin wrote:
> On Fri, 15 Oct 2021 11:21:24 -0700 (PDT), Rich S
> <richsulinengineer@gmail.com> wrote:
>
>> On Friday, October 15, 2021 at 6:01:14 PM UTC, John Larkin wrote:
>>> https://www.digikey.com/en/products/detail/microchip-technology/JANS1N4102DUR-1-TR/13995295
>>>
>>> Somebody must buy them.
>>>
>>> --
>>>
>>> If a man will begin with certainties, he shall end with doubts,
>>> but if he will be content to begin with doubts he shall end in certainties.
>>> Francis Bacon
>>
>> Avalanche 8.7 volts, seems odd, probably associated with a one design or
>> application. (input clamp?).
>> Must be some extant military gear with support contract, keeping the
>> (sub)contractor in business.
>> $140 for a mil-spec part,.. I dunno, haven't kept up on these, but honestly isn't
>> a surprise to me...
>>
>> =RS
>
> I need an 8.7 v 2% zener as a clamp, to protect a $300 distributed amp
> chip rated for 9 volts abs max. Parts are hard to get lately.
>
> I'll go for 5% and pray.
>
Would about 8.22V 1% do? Low power part as spec is 100uA nominal
500uA max (to 200C).
Fudge by adding a diode in series, which can be thermally coupled,
time constant maybe 10mSec worst case.
Thanks, R.Baer
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Cheap - - $3.54/week.
Could be low noise, as 8.7 V is in the low noise "valley"; especially
for certain manufacturers.
--
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Reply by boB●October 16, 20212021-10-16
On Fri, 15 Oct 2021 11:50:54 -0700 (PDT), Lasse Langwadt Christensen
<langwadt@fonz.dk> wrote:
>fredag den 15. oktober 2021 kl. 20.43.17 UTC+2 skrev John Larkin:
>> On Fri, 15 Oct 2021 11:24:12 -0700 (PDT), Rich S
>> <richsuli...@gmail.com> wrote:
>>
>> >
>> >> Avalanche 8.7 volts, seems odd, probably associated with a one design or
>> >> application. (input clamp?).
>> >> Must be some extant military gear with support contract, keeping the
>> >> (sub)contractor in business.
>> >> $140 for a mil-spec part,.. I dunno, haven't kept up on these, but honestly isn't
>> >> a surprise to me...
>> >>
>> >> =RS
>> >
>> >..because.. (for newbies)
>> >for mil-spec you're also paying for testing, documentation,
>> >and traceability all attached to that part. (Producing the part itself is
>> >just a small part!
>> >
>> >= RS
>> They are robbing people like military and semiconductor copy-exact
>> users who can't easily change things.
>
>also stops other people buying the, I assume, limited number of parts
>is of the exact type and that has all the paperwork
There are zero of these in stock. Anywhere.
No WONDER they are so expensive. They are unobtanium !
Reply by Jan Panteltje●October 16, 20212021-10-16
On a sunny day (Fri, 15 Oct 2021 22:39:14 -0700 (PDT)) it happened Ed Lee
<edward.ming.lee@gmail.com> wrote in
<80ff42d4-b0c1-45f4-92fd-9acb2c0a84bdn@googlegroups.com>:
>On Friday, October 15, 2021 at 10:30:22 PM UTC-7, Jan Panteltje wrote:
>> On a sunny day (Fri, 15 Oct 2021 15:44:35 -0700 (PDT)) it happened Ed Lee
>> <edward....@gmail.com> wrote in
>> <a9490547-a634-4174...@googlegroups.com>:
>> >On Friday, October 15, 2021 at 1:02:28 PM UTC-7, Jan Panteltje wrote:
>> >> On a sunny day (Fri, 15 Oct 2021 11:41:25 -0700) it happened John Larkin
>> >> <jlarkin@highland_atwork_technology.com> wrote in
>> >> <9mijmglv4q0sqcjvl...@4ax.com>:
>> >> >I need an 8.7 v 2% zener as a clamp, to protect a $300 distributed amp
>> >> >chip rated for 9 volts abs max. Parts are hard to get lately.
>> >> >
>> >> >I'll go for 5% and pray.
>> >> There are many ways to do that,
>> >> simple transistor and trimpot between - and + on base will allow you to select a voltage.
>> >>
>> >>
>> >> ________|
>> >> | |
>> >> | c
>> >> []<---- b
>> >> | e
>> >> | |
>> >> --------|
>> >>
>> >>
>> >> depends on current etc..
>> >>
>> >> Or maybe some LEDs in series (have that working here in my PIC programmer).
>> >> Or 2 zeners and / or diodes in series.
>> >>
>> >> In times of 'sjip' shortages BJTs and LEDs etc are cool.
>> >> It will get worse with power shortages, just ordered a 250 Ah liion 12V battery
>> >> from Aliexpress, for buffer...
>> >
>> >Why 12v? 8.7v is exactly two Li-Ion batteries in series. A Leaf battery module is 8.7v with center tap, and can sink 66A or
>> >500Whr.
>> I am talking about Ah, not Wh!
>
>I know, but we are comparing different voltages, so it makes more sense to compare Wh. I don't know how much power John needed,
>but i doubt more than one 500Wh module.
>
>> So 12V at 250 Ah makes??? < complicated math here>
>> Yes I have several small Liion 2 cell, 3 cell, 1 cell in various projects.
>> This is lifepo4, bit more safe cannot go up in flames by itself,
>> The 12V will go into a true sine to 230 V converter.
>> It is also in a water proof housing plus charge control so it can be used in a boat.
>> Bigger ones can power an outboard motor for a while.
>> Experiment.. Can start your car too.
>
>He is limiting the power source to 8.7v; so, 8.7v battery makes more sense than 12v.
OK, my fault, I was changing topic, do not want to use my battery as zener!
liion will go up to 4.2V per cell! From 3.2 V when low, so way out of
his 5 percent range.
Reply by Ed Lee●October 16, 20212021-10-16
On Friday, October 15, 2021 at 10:30:22 PM UTC-7, Jan Panteltje wrote:
> On a sunny day (Fri, 15 Oct 2021 15:44:35 -0700 (PDT)) it happened Ed Lee
> <edward....@gmail.com> wrote in
> <a9490547-a634-4174...@googlegroups.com>:
> >On Friday, October 15, 2021 at 1:02:28 PM UTC-7, Jan Panteltje wrote:
> >> On a sunny day (Fri, 15 Oct 2021 11:41:25 -0700) it happened John Larkin
> >> <jlarkin@highland_atwork_technology.com> wrote in
> >> <9mijmglv4q0sqcjvl...@4ax.com>:
> >> >I need an 8.7 v 2% zener as a clamp, to protect a $300 distributed amp
> >> >chip rated for 9 volts abs max. Parts are hard to get lately.
> >> >
> >> >I'll go for 5% and pray.
> >> There are many ways to do that,
> >> simple transistor and trimpot between - and + on base will allow you to select a voltage.
> >>
> >>
> >> ________|
> >> | |
> >> | c
> >> []<---- b
> >> | e
> >> | |
> >> --------|
> >>
> >>
> >> depends on current etc..
> >>
> >> Or maybe some LEDs in series (have that working here in my PIC programmer).
> >> Or 2 zeners and / or diodes in series.
> >>
> >> In times of 'sjip' shortages BJTs and LEDs etc are cool.
> >> It will get worse with power shortages, just ordered a 250 Ah liion 12V battery
> >> from Aliexpress, for buffer...
> >
> >Why 12v? 8.7v is exactly two Li-Ion batteries in series. A Leaf battery module is 8.7v with center tap, and can sink 66A or
> >500Whr.
> I am talking about Ah, not Wh!
I know, but we are comparing different voltages, so it makes more sense to compare Wh. I don't know how much power John needed, but i doubt more than one 500Wh module.
> So 12V at 250 Ah makes??? < complicated math here>
> Yes I have several small Liion 2 cell, 3 cell, 1 cell in various projects.
> This is lifepo4, bit more safe cannot go up in flames by itself,
> The 12V will go into a true sine to 230 V converter.
> It is also in a water proof housing plus charge control so it can be used in a boat.
> Bigger ones can power an outboard motor for a while.
> Experiment.. Can start your car too.
He is limiting the power source to 8.7v; so, 8.7v battery makes more sense than 12v.
Reply by Jan Panteltje●October 16, 20212021-10-16
On a sunny day (Fri, 15 Oct 2021 15:44:35 -0700 (PDT)) it happened Ed Lee
<edward.ming.lee@gmail.com> wrote in
<a9490547-a634-4174-8a59-ad24d50fe2b1n@googlegroups.com>:
>On Friday, October 15, 2021 at 1:02:28 PM UTC-7, Jan Panteltje wrote:
>> On a sunny day (Fri, 15 Oct 2021 11:41:25 -0700) it happened John Larkin
>> <jlarkin@highland_atwork_technology.com> wrote in
>> <9mijmglv4q0sqcjvl...@4ax.com>:
>> >I need an 8.7 v 2% zener as a clamp, to protect a $300 distributed amp
>> >chip rated for 9 volts abs max. Parts are hard to get lately.
>> >
>> >I'll go for 5% and pray.
>> There are many ways to do that,
>> simple transistor and trimpot between - and + on base will allow you to select a voltage.
>>
>>
>> ________|
>> | |
>> | c
>> []<---- b
>> | e
>> | |
>> --------|
>>
>>
>> depends on current etc..
>>
>> Or maybe some LEDs in series (have that working here in my PIC programmer).
>> Or 2 zeners and / or diodes in series.
>>
>> In times of 'sjip' shortages BJTs and LEDs etc are cool.
>> It will get worse with power shortages, just ordered a 250 Ah liion 12V battery
>> from Aliexpress, for buffer...
>
>Why 12v? 8.7v is exactly two Li-Ion batteries in series. A Leaf battery module is 8.7v with center tap, and can sink 66A or
>500Whr.
I am talking about Ah, not Wh!
So 12V at 250 Ah makes??? < complicated math here>
Yes I have several small Liion 2 cell, 3 cell, 1 cell in various projects.
This is lifepo4, bit more safe cannot go up in flames by itself,
The 12V will go into a true sine to 230 V converter.
It is also in a water proof housing plus charge control so it can be used in a boat.
Bigger ones can power an outboard motor for a while.
Experiment.. Can start your car too.