RE: Creepage dist. for more than 1000V ?

I hesitate to remind you all, but if anyone has a problem "interpreting" the requirements of IEC 60950, there is the TC74 Chairman's Advisory Panel. Briefly, the procedure is as follows : Questions for interpretation should, as a minimum - define the problem, making reference to a specific sub

RE: Creepage dist. for more than 1000V ?

the tube to transistor age. -kyle -Original Message- From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: Friday, August 03, 2001 1:15 AM To: emc-p...@majordomo.ieee.org Subject: Re: Creepage dist. for more than 1000V ? <95fbd8b0830ed511b7720002a51363f1319...@exw-ks.ks.lsil.

Re: Creepage dist. for more than 1000V ?

<95fbd8b0830ed511b7720002a51363f1319...@exw-ks.ks.lsil.com>, Ehler, Kyle inimitably wrote: >Ah yes, the blissful aroma of hot tubes, ozone and fried flybacks..those >were the days.. Didn't you have selenium rectifiers, too.? Inhaling selenium dioxide in small amounts can be good for thr

Re: Creepage dist. for more than 1000V ?

, Terry Meck inimitably wrote: >I don't recall the Sony but do recall the Philco and that Zenith held out with >the `hand wired' chassis. ITT-KB went back to 'hand-wired' as a marketing point in 1963 (IIRC), because of overheating problems with the previous all-printed designs. -- Regards, Joh

Re: Creepage dist. for more than 1000V ?

, Terry Meck inimitably wrote: > >You can't change the facts. So yes! In the Middle to late 50's. :-) > John Woodgate 08/01/01 03:16PM >>> > >, Terry Meck inimitably >wrote: >>I saw the first PCB show up in TVs, > >Would you care to put a date on that? Well, I asked because in Britain

RE: Creepage dist. for more than 1000V ?

G radio w/4 channels.. Globar resistor, or at least a shadow of where it WAS.. Ah yes, the blissful aroma of hot tubes, ozone and fried flybacks..those were the days.. I was sooo good that I retired after 10 months.. -kyle =:) -Original Message- From: Rich Nute [mailto:ri...@sdd.hp.com] S

RE: Creepage dist. for more than 1000V ?

27;s. I also worked in TV shops during school and can remember thoroughly cooked PCB materials. Regards, Jack Xerox EMC -Original Message- From: Rich Nute [mailto:ri...@sdd.hp.com] Sent: Thursday, August 02, 2001 10:45 AM To: emc-p...@majordomo.ieee.org Subject: Re: Creepage dist. for mor

Re: Creepage dist. for more than 1000V ?

Rich: The reason Zenith was using the `hand wired' promo was the `cold' and overheated PC boards especially the tube sockets that unsoldered themselves or when the trace separated from the board. This takes me back to the creapage point. I remember cutting away base board material, actually

Re: Creepage dist. for more than 1000V ?

Rich: My resolution when we go that far back is +/- 5 years minimum :-) :-) I don't recall the Sony but do recall the Philco and that Zenith held out with the `hand wired' chassis. Terry >>> Rich Nute 08/02/01 12:38PM >>> > >I saw the first PCB show up in TVs, > > Would you care to

Re: Creepage dist. for more than 1000V ?

Hi Terry: > I don't recall the Sony but do recall the Philco and that Zenith held out > with the `hand wired' chassis. Now that you mention it... I do indeed recall that campaign. But, I did not -- then -- realize the context. Today, looking back, that campaign was really quite absurd!

Re: Creepage dist. for more than 1000V ?

> >I saw the first PCB show up in TVs, > > Would you care to put a date on that? > > You can't change the facts. So yes! In the Middle to late 50's. :-) Having been a TV serviceman until 1960 (end of my college days), I saw no PCBs in USA TVs. I do recall PCBs in circa 1963 TVs

Re: Creepage dist. for more than 1000V ?

You can't change the facts. So yes! In the Middle to late 50's. :-) >>> John Woodgate 08/01/01 03:16PM >>> , Terry Meck inimitably wrote: >I saw the first PCB show up in TVs, Would you care to put a date on that? -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.c

Re: Creepage dist. for more than 1000V ?

, Terry Meck inimitably wrote: >I saw the first PCB show up in TVs, Would you care to put a date on that? -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk This message and its contents are not confidential, privileged or protected by law. Access is only authoris

Re: Creepage dist. for more than 1000V ?

Rich: As always I appreciated your eloquent explanation of the concept of the creapage requirement. Unfortunately experience has taught me long before your email. My question was based on the fact the standard does not SEEM to address the larger creapage distance >1000 volts. My reasoning c

Re: Creepage dist. for more than 1000V ?

Rich, Interesting info about how arcs form across PCBs, wish I had knew this a few years back. In this case I had a situation where PSUs were being taken down by fabric form ESD coats. The general non conductive cotton and polyester was settling between comports and an occasional, very conduct

Re: Creepage dist. for more than 1000V ?

"Terry Meck" wrote: > > Hi Rich: > > I thought the lack of creapage spec. at >1000 V is that the dielectric > strength of air would be less then the insulating material and surface > accumulated contaminates. As a result the clearance distance would > be the first to break down >1000 Volts. > > A

Re: Creepage dist. for more than 1000V ?

Hi Terry: > I thought the lack of creapage spec. at >1000 V is that the dielectric > strength of air would be less then the insulating material and surface > accumulated contaminates. As a result the clearance distance would be the > first to break down >1000 Volts. In general, the ele

Re: Creepage dist. for more than 1000V ?

Hi Rich: I thought the lack of creapage spec. at >1000 V is that the dielectric strength of air would be less then the insulating material and surface accumulated contaminates. As a result the clearance distance would be the first to break down >1000 Volts. Am I wrong? Best regards, Terry

Re: Creepage dist. for more than 1000V ?

Hi Israel and John: > >I wonder how to specify creepage distance for Information Technology > >Equipment.Table 6 in UL1950 or EN60950 specifies minimum creepage of > >10 mm for Working voltage = 1000 V, pollution degree 2, material group IIIb > >(basic insulation) linear Interpo

RE: Creepage dist. for more than 1000V ?

some, is not to others. James Goedderz Sensormatic > -- > From: John Woodgate[SMTP:j...@jmwa.demon.co.uk] > Reply To: John Woodgate > Sent: Monday, July 30, 2001 2:04 AM > To: emc-p...@majordomo.ieee.org > Subject: Re: Creepage dist. f

Re: Creepage dist. for more than 1000V ?

<000601c11881$36e04600$1e44d1d1@stella>, Vygovsky, Yury inimitably wrote: >By interpolation the creepage for 1500v = 15mm or more, for 2000v=20mm or >more. No, that would be extrapolation, and the standard doesn't say you can do that. -- Regards, John Woodgate, OOO - Own Opinions Only. http://w

Re: Creepage dist. for more than 1000V ?

, Israel Yeshurun inimitably wrote: >I wonder how to specify creepage distance for Information Technology >Equipment.Table 6 in UL1950 or EN60950 specifies minimum creepage of >10 mm for Working voltage = 1000 V, pollution degree 2, material group IIIb >(basic insulation) linear Interpolati

Re: Creepage dist. for more than 1000V ?

PM Subject: Creepage dist. for more than 1000V ? > > >Hello all ! > >I wonder how to specify creepage distance for Information Technology >Equipment.Table 6 in UL1950 or EN60950 specifies minimum creepage of >10 mm for Working voltage = 1000 V, pollution degree

Creepage dist. for more than 1000V ?

Hello all ! I wonder how to specify creepage distance for Information Technology Equipment.Table 6 in UL1950 or EN60950 specifies minimum creepage of 10 mm for Working voltage = 1000 V, pollution degree 2, material group IIIb (basic insulation) linear Interpolation is permitted bet