Body
http://www.angelfire.com/electronic/funwithtubes/Amp-Power_Supply-More_Info.html
Very good article on HVDC power supplies and filter section!
On 11/4/2018 7:50 AM, Norman Wootan wrote:
>
> Mick! Your comment about some people dying from pranks! True Story!
> Back in the early 80s a pastor at a Duncanville Church (suburb of
> Dallas) was preforming a live Baptism at his church on a typical
> Sunday morning! His audio amp was the old vintage single end class A
> push-pull tube amp. As he descended into the Baptism pool in front of
> congregation and flipped on the hand held mic switch has was instantly
> fried by 450VDC plate voltage on chassis ground. Coroners report
> showed that an electrolytic cap in the HVDC plate power supply had
> gone to ground in effect energizing chassis at the 450VDC potential.
> All those vintage amps had the old two pin 120VAC plugs before the 3
> pin safety grounds we now have.
>
> http://www.angelfire.com/electronic/funwithtubes/Amp-Power_Supply.html
>
> Having gone through DeVry Electronics back in 1953, I totally
> understood the lethality of such an event!
>
>
> On 11/3/2018 7:55 PM, Mick [email protected] [EVGRAY] wrote:
>>
>> Norm,
>>
>> The interconnects used for home audio should be illegal for bad
>> sound, but even a properly designed mic cable with an XLR on each end
>> with a hot a cold and a shield one will notice only on female side
>> the shield connects to the chassis of the connector. It is a single
>> shield run on #1 to both sides though as the connections are designed
>> balanced for just the reason you mentioned.
>>
>> XLR's are the best connector for long run connections but I make my
>> own cable with silver plated aircraft cable with teflon insulation, a
>> pain to work with but sound is great.
>>
>> For short single ended runs the RCA end sucks and it should have been
>> BNC or the extra small microwave connectors that look like mini
>> BNC's If one removes the RCA connectors and replaces with BNC and
>> high quality aircraft cable and the rest of the gear is good enough
>> one will notice the difference. Networking cable Cat 5 or 6 can also
>> sound great as speaker cable.
>>
>> The story gets worse though as the old tube guitar amp had a switch
>> that would toggle chassis ground between either connector on the
>> power connection for the purpose of preventing ground loops when some
>> live show venue had the outlets wired with hot and neutral reversed.
>> Well when that guitarist also happens to be a vocalist and touched a
>> mic stand with the ground switched wrong it was not pretty if the
>> shield was run to both chassis of the connectors. This was an old
>> soundman trick to get back at the rude ego asshole guitar players
>> using the special fully grounded mic cable. I am sure some people
>> died from this prank where 220 was used.
>>
>>
>> On 11/3/2018 4:46 PM, Norman Wootan [email protected] [EVGRAY] wrote:
>>>
>>> Mick! Just had to laugh at your remark about floating grounds in
>>> the recording studio! Ha! Ha! Way back when I was learning about
>>> fine audio, I ran a shielded line level audio cable to hook two
>>> sound systems together, about 100 ft run. When I turned on the
>>> systems and selected line in on the 2nd system, I had the prettiest
>>> motor boat you ever heard! Lol Yep! I had grounded both ends of a
>>> shielded cable and got a good example of a ground loop!
>>>
>>>
>>> On 11/3/2018 4:54 PM, Mick [email protected] [EVGRAY] wrote:
>>>>
>>>> Norm,
>>>>
>>>> Thanks for that.
>>>>
>>>> I love Mr Calrsons lab, I could happily live there for quite awhile
>>>> with all that awesome vintage gear. I have seen isolation
>>>> transformers wired like that and it's so insane but I am used to
>>>> testing all the grounding points. When building a recording studio
>>>> we have to float all the grounds so they are single point at the
>>>> service panel and not looped anywhere else. Often they are lifted
>>>> at the outlet j-box due to the lack of control in a prewired
>>>> building. Ironically we also used to use autoformers for all of
>>>> the light dimmers to prevent noise, so we often referred to the
>>>> variacs as light dimmers.
>>>>
>>>> I still don't completely trust a scope on an isolation transformer
>>>> even if the ground is properly isolated/ lifted due to the somewhat
>>>> rare magnetic emp events we are talking about like when I kicked
>>>> off all my ground faults in the house through one.
>>>>
>>>>
>>>> On 11/3/2018 2:03 PM, Norman Wootan [email protected] [EVGRAY] wrote:
>>>>>
>>>>> Mick! Here is a helpful video regarding scopes and isolation
>>>>> transformers on the test bench!
>>>>>
>>>>> https://www.youtube.com/watch?v=XBsQ3sZ45Fk&feature=youtu.be
>>>>>
>>>>> https://www.youtube.com/watch?v=xaELqAo4kkQ
>>>>>
>>>>>
>>>>> On 11/3/2018 12:36 PM, Mick [email protected] [EVGRAY] wrote:
>>>>>>
>>>>>> Norm,
>>>>>>
>>>>>> Thanks for the nudge in the right direction. Now the process
>>>>>> demands repeating with a totally isolated battery source
>>>>>> configured the same way. Funny how I was concentrating on
>>>>>> isolating and connecting saturated inductive charge without the
>>>>>> first magnetic variable taken into account.
>>>>>>
>>>>>> I have had no problem creating the event with my grid power
>>>>>> source and even warned Sven that an isolation transformer will
>>>>>> not always protect his scope when messing around with this
>>>>>> energy. My scope probe sitting on a bench shot me in the leg
>>>>>> when I walked by when performing the experiments from my bench
>>>>>> supply. The bench supply has an isolation transformer of sorts.
>>>>>> Being it is torroidal there is more inter-winding capacitive
>>>>>> coupling and mutual inductance than with the proper EI
>>>>>> transformer though there is at least the electrostatic shield and
>>>>>> galvanic isolation.
>>>>>>
>>>>>> Thanks for that reference. the Brit guy was funny, although I'm
>>>>>> very familiar with iso transformers in audio work used for
>>>>>> galvanic isolation and balancing to eliminate common mode noise.
>>>>>>
>>>>>>
>>>>>> On 11/3/2018 4:42 AM, Norman Wootan [email protected] [EVGRAY] wrote:
>>>>>>>
>>>>>>> Mick! Your DUH reference is funny! To understand
>>>>>>> Isolation, best to study and understand the Isolation
>>>>>>> Transformer. The super high quality ones are built to
>>>>>>> eliminate noise and DC components that effect sensitive
>>>>>>> instruments like EEG and EKG instruments. This will give you an
>>>>>>> idea as to construction and purpose::
>>>>>>>
>>>>>>> https://en.m.wikipedia.org/wiki/Isolation_transformer
>>>>>>>
>>>>>>> A little tutorial as to how they work!
>>>>>>>
>>>>>>> https://www.youtube.com/watch?v=sfzy5IQMzyc&feature=youtu.be
>>>>>>>
>>>>>>> https://www.youtube.com/watch?v=14kPQif9P7c&feature=youtu.be
>>>>>>>
>>>>>>> https://toroid.com/Products/Medical-Isolation-Transformers
>>>>>>>
>>>>>>> The 230VAC, 5 HP locked rotor experiment was an example of
>>>>>>> electrically isolated electrical circuitry when mains contactor
>>>>>>> was opened since there was no neutral involve. There is magnetic
>>>>>>> and capacitive coup[ling only The dielectric insulation was
>>>>>>> not compromised therefore no electrical connection. The Chinese
>>>>>>> motor experiment was isolated, (electrically) when the reversing
>>>>>>> action was in transient. (Floating neutral) since there is a
>>>>>>> line neutral in the 120VAC input.
>>>>>>>
>>>>>>>
>>>>>>> On 11/2/2018 2:44 PM, Mick [email protected] [EVGRAY] wrote:
>>>>>>>>
>>>>>>>> Norm,
>>>>>>>>
>>>>>>>> Since you have performed mass research on this event would you
>>>>>>>> concur
>>>>>>>> with my long distance observation that the event is not only due to
>>>>>>>> charge isolation but inclusive of a magnetic connection from
>>>>>>>> source in
>>>>>>>> addition to the saturated and lifted inductive load?
>>>>>>>>
>>>>>>>> Your bell buzzer and bell transformer acting as an isolation
>>>>>>>> transformer.
>>>>>>>>
>>>>>>>> Both motor experiments, the small Emerson type and the HVAC
>>>>>>>> unit with
>>>>>>>> only two hot's no neutral, must have been powered by an isolation
>>>>>>>> transformer of some type also such as the utility step down for the
>>>>>>>> neighborhood or dedicated delta or wye for commercial or even
>>>>>>>> acted as
>>>>>>>> such from the dual windings of the HVAC motor.
>>>>>>>>
>>>>>>>> Have you reliably produced the NS from any type of isolated battery
>>>>>>>> system, or in all such cases was there a magnetic connection to
>>>>>>>> an earth
>>>>>>>> bonding in another spot?
>>>>>>>>
>>>>>>>> My thoughts being one side of a transformer acting as a source is
>>>>>>>> grounded and the secondary side isolated so that the only
>>>>>>>> conceivable
>>>>>>>> ground bonding on the sink might be considered as magnetic
>>>>>>>> aside from
>>>>>>>> the bonded motor frame or what not producing the reconnection.
>>>>>>>>
>>>>>>>> I may be pissing up a rope notwithstanding the NS seems to be
>>>>>>>> predicated
>>>>>>>> on a B field connection somewhere in the source feed though the
>>>>>>>> neutral
>>>>>>>> is isolated electrically.
>>>>>>>>
>>>>>>>> Perhaps this is a simple "Duh" to you that you had already
>>>>>>>> figured out
>>>>>>>> assuming everyone else at least this smart. Either way it does
>>>>>>>> create
>>>>>>>> an interesting position in which to view 3 phase and
>>>>>>>> transformers with
>>>>>>>> an extra resonant winding.
>>>>>>>>
>>>>>>>> By the way, ironic your implication that the large medical
>>>>>>>> isolation
>>>>>>>> transformers create a heretofore unknown vector of extreme danger.
>>>>>>>>
>>>>>>>> Mick
>>>>>>>>
>>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>>
>>
>