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Phil, Gareth, Trevor, anyone ... ?
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Arfa Daily
Jan 31, 2014, 10:27:33 AM1/31/14
to
... got any experience of the Ecler "PAM" series of high-power slave amps ?
Specifically why the output relays have had a half inch disc magnet glued to
either side of their cases, at the bottom, and in line with the contact set.
These magnets are detailed as a mechanical fitting drawing in the service
manual, even down to which pole should face in, but nothing that I can see
in the notes as to why they have been fitted. Also, anyone got any
experience of working on these (1400 and 1000 models), and in particular,
the complex logic-controlled protection circuit on the back board where the
output relays are ?
Arfa
Specifically why the output relays have had a half inch disc magnet glued to
either side of their cases, at the bottom, and in line with the contact set.
These magnets are detailed as a mechanical fitting drawing in the service
manual, even down to which pole should face in, but nothing that I can see
in the notes as to why they have been fitted. Also, anyone got any
experience of working on these (1400 and 1000 models), and in particular,
the complex logic-controlled protection circuit on the back board where the
output relays are ?
Arfa
Gareth Magennis
Jan 31, 2014, 10:42:27 AM1/31/14
to
"Arfa Daily" <arfa....@ntlworld.com> wrote in message
news:FhPGu.218$zs5...@fx22.am4...
As for the magents, I believe they might be something to do with affecting
the arcing between contacts under various fault conditions?
Phil will know the complete details as I remember him posting on here before
about it.
Cheers,
Gareth.
N_Cook
Jan 31, 2014, 11:18:19 AM1/31/14
to
On 31/01/2014 15:27, Arfa Daily wrote:
> .... got any experience of the Ecler "PAM" series of high-power slave
Some sort of unpowered interlock? Magnets not strong enough to close the
contacts but once current has gone through the coil , the contacts
close. But if for some reason the current stops, then the contacts
remain closed until reverse powered open perhaps at start-up.
Which reminds me I was going to find out,but forgot, how the unpowered,
delay-open, door catches work on washing machines
> .... got any experience of the Ecler "PAM" series of high-power slave
contacts but once current has gone through the coil , the contacts
close. But if for some reason the current stops, then the contacts
remain closed until reverse powered open perhaps at start-up.
Which reminds me I was going to find out,but forgot, how the unpowered,
delay-open, door catches work on washing machines
Baron
Jan 31, 2014, 4:48:38 PM1/31/14
to
N_Cook scribbled thus:
> Which reminds me I was going to find out,but forgot, how the
> unpowered, delay-open, door catches work on washing machines
Thermal device !
--
Best Regards:
Baron.
> Which reminds me I was going to find out,but forgot, how the
> unpowered, delay-open, door catches work on washing machines
--
Best Regards:
Baron.
jurb...@gmail.com
Jan 31, 2014, 5:18:47 PM1/31/14
to
I had a quick look at the print and I can't say for sure, but I think it's possible that the magnets are there to aid the return springs. Looks like this baby can put out some serious current.
>"But if for some reason the current stops, then the contacts
remain closed until reverse powered open perhaps at start-up. ..."
Nope, nothing like that on the print.
>"But if for some reason the current stops, then the contacts
Nope, nothing like that on the print.
Gareth Magennis
Jan 31, 2014, 7:51:03 PM1/31/14
to
wrote in message
news:ab77ae6f-0054-4c0c...@googlegroups.com...
http://www.ia.omron.com/data_pdf/data_sheet/x_dsheet_csm570.pdf
Gareth.
Phil Allison
Jan 31, 2014, 11:28:55 PM1/31/14
to
"Gareth Magennis"
>> Arfa
>
> Not seen one of those before.
>
> As for the magents, I believe they might be something to do with affecting
> the arcing between contacts under various fault conditions?
>
> Phil will know the complete details as I remember him posting on here
> before about it.
>
** Someone has a good memory.
>
> Not seen one of those before.
>
> As for the magents, I believe they might be something to do with affecting
> the arcing between contacts under various fault conditions?
>
> Phil will know the complete details as I remember him posting on here
> before about it.
>
Similar magnets are attached to the relays in certain BGW amplifiers (
1980s, US made heavy weights) and no doubt for the same reason.
The purpose is to enhance the DC breaking capacity of the contacts - with DC
supplies above about 60V, ordinary relays cannot break arc that forms upon
opening IF the amp " goes DC".
The magnetic force causes arc to form into a U shape, making it longer and
far more likely to break.
IME, an 80V DC supply feeding into a 4ohm load via a large relay will break
this way - but *just* and probably only once !!!!!
It would have NO chance without the magnetic field.
... Phil
N_Cook
Feb 1, 2014, 5:35:44 AM2/1/14
to
On 31/01/2014 21:48, Baron wrote:
> N_Cook scribbled thus:
>
>> Which reminds me I was going to find out,but forgot, how the
>> unpowered, delay-open, door catches work on washing machines
>
> Thermal device !
>
resourceful stuff that bimetal, from watch escapements , via vehicle
> N_Cook scribbled thus:
>
>> Which reminds me I was going to find out,but forgot, how the
>> unpowered, delay-open, door catches work on washing machines
>
> Thermal device !
>
lamp flashers, flourescent tube starters to washing machines, it gets
everywhere
Arfa Daily
Feb 1, 2014, 5:55:28 AM2/1/14
to
"Phil Allison" <phi...@tpg.com.au> wrote in message
news:bl3bgf...@mid.individual.net...
? I currently have seven of them in, all of which seem to have faults in the
very complex protection circuit, which amongst other things, cuts the supply
to an opamp on the power amp boards, which then causes the amp to actually
produce some DC on its output ...
Arfa
Gareth Magennis
Feb 1, 2014, 9:05:42 AM2/1/14
to
Arfa Daily
Feb 1, 2014, 9:57:58 AM2/1/14
to
"Gareth Magennis" <gareth....@ntlworld.com> wrote in message
news:Xa7Hu.464$Y17...@fx15.am4...
Arfa
jurb...@gmail.com
Feb 1, 2014, 1:20:07 PM2/1/14
to
>"Similar magnets are attached to the relays in certain BGW amplifiers (
1980s, US made heavy weights) and no doubt for the same reason. "
You Sir, have redeemed yourself. I thought it impossibble really. Take a bow(ow) LOL.
1980s, US made heavy weights) and no doubt for the same reason. "
I shit you not. I'm a pretty fart smeller y'know and I was sure it had something to do with the ridiculous eardrum-melting current but in my morning after you actually opened up a little corner of my mind that had been dormant for some time. I KNEW it had something to do with current, but to extrapolate, it is wholly possible that such an amplifier would be driving a chiefly inductive load. WTF did I think was going to happen with 80 fucking volts across a (voice) coil ?
<(me)DUMKOPF ! It's not a weak spring, it's the fact that plasma can melt even the shiniest of silver plating and weld it quite effectively. One of those moments.
Now I know why we keep you around you autistic, Tourettite scallywag scoundrel !
Back to your regularly scheduled bullshit. Be well. And don't forget to eat shit and die !
LOL
(I mean it Phil, I would heve never thought of that in, well, not a MILLION years but maybe a thousand)
Gareth Magennis
Feb 1, 2014, 1:57:27 PM2/1/14
to
"Phil Allison" wrote in message news:bl3bgf...@mid.individual.net...
speaker relay's normally off terminal, so a "DC fault" amplifier doesn't fry
the speakers via the arc that doesn't die.
(In the absence of a magnet)
I remember you posting about that somewhere too.
This stuff does stay in my head sometimes you know.
Cheers,
Gareth.
Michael A. Terrell
Feb 1, 2014, 6:45:58 PM2/1/14
to
Phil Allison
Feb 1, 2014, 8:19:23 PM2/1/14
to
"Gareth Magennis"
> "Phil Allison" "Gareth Magennis"
>>> Arfa
>>
>> Not seen one of those before.
>>
>> As for the magents, I believe they might be something to do with
>> affecting
>> the arcing between contacts under various fault conditions?
>>
>> Phil will know the complete details as I remember him posting on here
>> before about it.
>>
>
> ** Someone has a good memory.
>
> Similar magnets are attached to the relays in certain BGW amplifiers (
> 1980s, US made heavy weights) and no doubt for the same reason.
>
> The purpose is to enhance the DC breaking capacity of the contacts - with
> DC
> supplies above about 60V, ordinary relays cannot break arc that forms upon
> opening IF the amp " goes DC".
>
> The magnetic force causes arc to form into a U shape, making it longer and
> far more likely to break.
>
> IME, an 80V DC supply feeding into a 4ohm load via a large relay will
> break
> this way - but *just* and probably only once !!!!!
>
> It would have NO chance without the magnetic field.
>
>
>>
>> Not seen one of those before.
>>
>> As for the magents, I believe they might be something to do with
>> affecting
>> the arcing between contacts under various fault conditions?
>>
>> Phil will know the complete details as I remember him posting on here
>> before about it.
>>
>
> ** Someone has a good memory.
>
> Similar magnets are attached to the relays in certain BGW amplifiers (
> 1980s, US made heavy weights) and no doubt for the same reason.
>
> The purpose is to enhance the DC breaking capacity of the contacts - with
> DC
> supplies above about 60V, ordinary relays cannot break arc that forms upon
> opening IF the amp " goes DC".
>
> The magnetic force causes arc to form into a U shape, making it longer and
> far more likely to break.
>
> IME, an 80V DC supply feeding into a 4ohm load via a large relay will
> break
> this way - but *just* and probably only once !!!!!
>
> It would have NO chance without the magnetic field.
>
>
> Phil, you have to also tell us the extremely relevant story of grounding
> the
> speaker relay's normally off terminal, so a "DC fault" amplifier doesn't
> fry
> the speakers via the arc that doesn't die.
** Some power amps use that idea ( ie diverting the arc to ground while
> the
> speaker relay's normally off terminal, so a "DC fault" amplifier doesn't
> fry
> the speakers via the arc that doesn't die.
shorting the speakers ) but there has to be fuses in each DC supply rail -
or you will soon have a fire on your hands.
.... Phil
Gareth Magennis
Feb 1, 2014, 8:29:34 PM2/1/14
to
"Phil Allison" wrote in message news:bl5kom...@mid.individual.net...
speakers.
I note that some Peavey amps, for example, do not have any speaker relays at
all, but use a SCR/Triac to short the output in the event of DC, saving the
speakers, but blowing the amps, which dont appear to be fused properly for
such an occurrence.
Gareth.
Gareth.
N_Cook
Feb 2, 2014, 6:43:37 AM2/2/14
to
resilient backing, rather than for its differential temperature
coefficients of expansion, ie bending on heating property
N_Cook
Feb 2, 2014, 6:50:10 AM2/2/14
to
I like the bi-metal discs that you get in thermal switches, that
suddenly dome in the opposite sense at a precise temperature, and built
in hysterisis as well , before they will flip back the other way on
lowering of temperature.
Perhaps a bi-metal arrangement , even if requiring some diverted current
doing the heating instead of "in-passing" heating , would work as
heavy-duty DC relays, relying on this strong stored mechanical energy ,
rather than magnetism and springs to break contact
suddenly dome in the opposite sense at a precise temperature, and built
in hysterisis as well , before they will flip back the other way on
lowering of temperature.
Perhaps a bi-metal arrangement , even if requiring some diverted current
doing the heating instead of "in-passing" heating , would work as
heavy-duty DC relays, relying on this strong stored mechanical energy ,
rather than magnetism and springs to break contact
mrob...@att.net
Feb 2, 2014, 2:39:26 PM2/2/14
to
N_Cook <div...@tcp.co.uk> wrote:
> Perhaps a bi-metal arrangement , even if requiring some diverted
> current doing the heating instead of "in-passing" heating , would work
> as heavy-duty DC relays, relying on this strong stored mechanical
> energy , rather than magnetism and springs to break contact
Congratulations, you have invented an automotive turn signal (indicator)
> Perhaps a bi-metal arrangement , even if requiring some diverted
> current doing the heating instead of "in-passing" heating , would work
> as heavy-duty DC relays, relying on this strong stored mechanical
> energy , rather than magnetism and springs to break contact
flasher! :) The non-electronic ones work this way. Some of them rely
on the bimetal heating itself up from the lamp current, and some of them
have a small heating element to do it. Ratings to around 12 A at 12 V
DC nominal are available.
Matt Roberds
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