From: bill.sloman@ieee.org
On 13/11/2025 4:18 am, john larkin wrote:
> On Thu, 13 Nov 2025 03:55:03 +1100, Bill Sloman
> wrote:
>
>> On 13/11/2025 2:29 am, john larkin wrote:
>>> On Wed, 12 Nov 2025 02:05:28 -0500, "Edward Rawde"
>>> wrote:
>>>
>>>> "Bill Sloman" wrote in message news:
0f19b8$18b8d$1@dont-email.me...
>>>>> On 12/11/2025 4:24 pm, john larkin wrote:
>>>>>> On Wed, 12 Nov 2025 00:13:08 -0500, "Edward Rawde"
>>>>>> wrote:
>>>>>>
>>>>>>> Due to a "Header too long" message while trying to reply to Bill
Sloman's post at 11:41 PM in "coil impedance".
>>>>>>> Here is my reply.
>>>>>>>
>>>>>>> "Bill Sloman" wrote in message ne
s:10f135p$17b8q$1@dont-email.me...
>>>>>>>> On 12/11/2025 1:49 am, Edward Rawde wrote:
>>>>>>>>> "Bill Sloman" wrote in message
ews:10evhdm$p0a1$2@dont-email.me...
>>>>>>>>>> On 11/11/2025 11:12 pm, Edward Rawde wrote:
>>>>>>>>>>> "Bill Sloman" wrote in message
news:10eunlu$hv9m$1@dont-email.me...
>>>>>>>>>>>> On 11/11/2025 2:48 am, Edward Rawde wrote:
>>>>>>>>>>>>> "Bill Sloman" wrote in message
news:10es5mv$3r8qk$1@dont-email.me...
>>>>>>>>>>>>>> On 10/11/2025 4:01 pm, Edward Rawde wrote:
>>>>>>>>>>>>>>> "Bill Sloman" wrote in message
news:10erqko$3o5c0$6@dont-email.me...
>>>>>>>>>>>>>>>> On 10/11/2025 3:29 pm, Edward Rawde wrote:
>>>>>>>>>>>>>>>>> "Bill Sloman" wrote in message
news:10ermr8$3o5c0$1@dont-email.me...
>>>>>>>>>>>>>>>>>> On 10/11/2025 2:57 am, Edward Rawde wrote:
>>>>>>>>>>>>>>>>>>> "Bill Sloman" wrote in message
news:10epc7k$33b3h$1@dont-email.me...
>>>>>>>>>>>>>>>>>>>> On 9/11/2025 4:01 am, Edward Rawde wrote:
>>>>>>>>>>>>>>>>>>>>> "Bill Sloman" wrote in message
news:10emnnb$2cnh3$1@dont-email.me...
>>>>>>>>>>>>>>>>>>>>>> On 8/11/2025 4:49 am, Edward Rawde wrote:
>>>>>>>>>>>>>>>>>>>>>>> "Bill Sloman" wrote in message
news:10elb3i$20r3i$3@dont-email.me...
>>>>>>>>>>>>>>>>>>>>>>>> On 8/11/2025 3:31 am, Edward Rawde wrote:
>>>>>>>>>>>>>>>>>>>>>>>>> "Liz Tuddenham"
wrote in message
>>>>>>>>>>>>>>>>>>>>>>>>> news:1rlfnmd.5t4y3yjlsancN%liz@poppyre
ords.invalid.invalid...
>>>>>>>>>>>>>>>>>>>>>>>>>> Bill Sloman wrote:
>>>>>>>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>>>>>> On 7/11/2025 9:24 pm, Liz Tuddenham wrote:
>>>>>>>>>>>>>>>>>>>>>>>>>>>> Bill Sloman wrote:
>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>> On 7/11/2025 10:41 am, john larkin wrote:
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>> If you believe that I ever mentioned tantalum bead capacitors
anywhere
>>>>>>>>> else then you need to reference that post and the specific part of
it or shut up.
>>>>>>>>
>>>>>>>> I never said you did. The schematic just showed big capacitors, and
in real life they would have been tantalum bead parts.
>>>>>>>
>>>>>>> Excuse me while I fall about laughing.
>>>>>>>
>>>>>>> I could ask you to reference or post this schematic which showed big
capacitors (plural)
>>>>>>> but I'm not going to bother.
>>>>>
>>>>> I've got the file on my computer under the file name "John May
2025-02-15". The file shows C3 and C6 as 100uF electrolytics.
>>>>> You have to dig into the part name to find the word "tantalum".
>>>>>
>>>>>> Tantalums are prone to detonation, if handled badly. And they are
>>>>>> often handled badly.
>>>>>
>>>>> John Larkin may be in the habit of not taking data sheets seriously, but
more serious people are more careful. George Kent and
>>>>> Cambridge Instruments designed them into products, and they didn't
"detonate" in the field. Junior engineers did occasionally
>>>>> solder them into prototypes the wrong way around, but they didn't do it
twice.
>>>>
>>>> After fixing microfarad extraneous character issues I found that the
circuit you posted with the "tantalum" capacitors does
>>>> simulate.
>>>> But it is not equivalent to the circuit JM posted and it has much worse
harmonic performance.
>>>> And I have never seen it before.
>>
>> It was probably a tidied up version of what JM posted. I do remember
>> playing with it and finding it needed a lot of by-pass capacitance, at
>> R17 and R21. which would have needed to be electrolytic if it wasn't
>> going to be bulkier than the rest of the circuit put together.
>>
>>>> The only circuit I clearly remember (very very clearly) is the one with
the 470uF capacitor which JM certainly did post because I
>>>> just took it from his post.
>>>>
>>>> So I suspect that the "tantalum" version is a creation of your own which
you never posted until now.
>>>
>>> We don't often use tantalums these days. They do have about the right
>>> ESR to stabilize some older voltage regulators. They are reliable if
>>> peak current stays low, and if voltage derated at least 2:1.
>>>
>>> We use polymer aluminums whenever we can. Low ESR, low ESL, don't
>>> detonate or dry out. Adding ESR isn't difficult.
>>
>> I've seen them in catalogues, but haven't designed them into anything yet.
>
> They are great. The ones we use zener softly at about 1.4x rated
> voltage and just get warm. They tolerate reasonable reverse voltage.
Electrolytic capacitors don't zener. They break down. "Zener" diodes
that break down at reverse voltage higher than about 5V don't break down
by the Zener mechanism either - they avalanche. Electrolytic capacitors
break down by other mechanisms (and I never got deep enough into
electrochemistry to learn much about them).
--
Bill Sloman, Sydney
--- SoupGate-Win32 v1.05
* Origin: you cannot sedate... all the things you hate (1:229/2)
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