sci.electronics.repair - 26 new messages in 10 topics - digest

sci.electronics.repair
http://groups.google.com/group/sci.electronics.repair?hl=en

sci.electronics.repair@googlegroups.com

Today's topics:

==============================================================================
TOPIC: Michael A. Terrell must be killed ASAP.
http://groups.google.com/group/sci.electronics.repair/t/13b233689d902984?hl=en
==============================================================================

== 1 of 8 ==
Date: Tues, Sep 6 2011 2:44 am
From: "Michael A. Terrell"

Charles wrote:
>
> It would be a real blast to see all of the posers in one or more of these
> arenas:

> 4/ Street in an Atlanta ghetto

Why would we want to visit you, in your ghetto? Roy J Quijano of
Bronx, Ny. has been making death threats for years. It doesn't surprise
me that you are interested in his mindless rants and threats.

--
You can't have a sense of humor, if you have no sense.

== 2 of 8 ==
Date: Tues, Sep 6 2011 12:31 pm
From: The Ghost In The Machine

On Sep 6, 5:44 am, "Michael A. Terrell" <mike.terr...@earthlink.net>
wrote:
> Charles wrote:
>
> > It would be a real blast to see all of the posers in one or more of these
> > arenas:
> > 4/ Street in an Atlanta ghetto
>
> Why would we want to visit you, in your ghetto? Roy J Quijano of
> Bronx, Ny. has been making death threats for years. It doesn't surprise
> me that you are interested in his mindless rants and threats.
>
> --
> You can't have a sense of humor, if you have no sense.

SHUT UP FOOL...ROY JESUS QUIJANO IS NOT THE SUBJECT HERE..YOU ARE!
YOU ANTI-GOVERNMENT ANTI-PERSONNEL BASTARD.....GET A MOVE ON YOU
PSYCHO FREAK.
PATECUM
TGITM

== 3 of 8 ==
Date: Tues, Sep 6 2011 1:10 pm
From: Jamie

The Ghost In The Machine wrote:

> On Sep 6, 5:44 am, "Michael A. Terrell" <mike.terr...@earthlink.net>
> wrote:
>
>>Charles wrote:
>>
>>
>>>It would be a real blast to see all of the posers in one or more of these
>>>arenas:
>>>4/ Street in an Atlanta ghetto
>>
>> Why would we want to visit you, in your ghetto? Roy J Quijano of
>>Bronx, Ny. has been making death threats for years. It doesn't surprise
>>me that you are interested in his mindless rants and threats.
>>
>>--
>>You can't have a sense of humor, if you have no sense.
>
>
> SHUT UP FOOL...ROY JESUS QUIJANO IS NOT THE SUBJECT HERE..YOU ARE!
> YOU ANTI-GOVERNMENT ANTI-PERSONNEL BASTARD.....GET A MOVE ON YOU
> PSYCHO FREAK.
> PATECUM
> TGITM
You two are a perfect couple..

Jamie

== 4 of 8 ==
Date: Tues, Sep 6 2011 1:42 pm
From: "Charles"

"Michael A. Terrell" wrote in message
news:Q5-dnb6L_OTrdvjTnZ2dnUVZ_vKdnZ2d@earthlink.com...

Charles wrote:
>
> It would be a real blast to see all of the posers in one or more of these
> arenas:

> 4/ Street in an Atlanta ghetto

Why would we want to visit you, in your ghetto? Roy J Quijano of
Bronx, Ny. has been making death threats for years. It doesn't surprise
me that you are interested in his mindless rants and threats.

--
You can't have a sense of humor, if you have no sense.

Ahem! Sense? I was suggesting other, perhaps more fitting, venues for this
crap. Do you have any sense, as in common sense?

== 5 of 8 ==
Date: Tues, Sep 6 2011 2:38 pm
From: The Ghost In The Machine

On Sep 6, 4:42 pm, "Charles" <charlesschu...@comcast.net> wrote:
> "Michael A. Terrell" wrote in messagenews:Q5-dnb6L_OTrdvjTnZ2dnUVZ_vKdnZ2d@earthlink.com...
>
> Charles wrote:
>
> > It would be a real blast to see all of the posers in one or more of these
> > arenas:
> > 4/ Street in an Atlanta ghetto
>
> Why would we want to visit you, in your ghetto? Roy J Quijano of
> Bronx, Ny. has been making death threats for years. It doesn't surprise
> me that you are interested in his mindless rants and threats.
>
> --
> You can't have a sense of humor, if you have no sense.
>
> Ahem! Sense? I was suggesting other, perhaps more fitting, venues for this
> crap. Do you have any sense, as in common sense?

CHASKITTY SENSE IS NULL, MOOT, MORTAL, UNREAL, THEREFOR IRRELEVANT.
THANKS FOR BRINGING THIS BACK UP TOP THOUGH, IT IS A NATIONAL
PRIORITY.
BOOWAHAHAHAHA !
JAMIE, BITE CHAS.
PATECUM
TGITM

== 6 of 8 ==
Date: Tues, Sep 6 2011 9:03 pm
From: "Michael A. Terrell"

Charles wrote:
>
> "Michael A. Terrell" wrote in message
> news:Q5-dnb6L_OTrdvjTnZ2dnUVZ_vKdnZ2d@earthlink.com...
>
> Charles wrote:
> >
> > It would be a real blast to see all of the posers in one or more of these
> > arenas:
>
> > 4/ Street in an Atlanta ghetto
>
> Why would we want to visit you, in your ghetto? Roy J Quijano of
> Bronx, Ny. has been making death threats for years. It doesn't surprise
> me that you are interested in his mindless rants and threats.
>
> --
> You can't have a sense of humor, if you have no sense.
>
> Ahem! Sense? I was suggesting other, perhaps more fitting, venues for this
> crap. Do you have any sense, as in common sense?

Yawn. Go complain about cheap TV speakers again. We're still
laughing at you over that one, because it shows that you not only have
no sense, but you've never had any.

--
You can't have a sense of humor, if you have no sense.

== 7 of 8 ==
Date: Wed, Sep 7 2011 3:07 am
From: The Ghost In The Machine

On Sep 7, 12:03 am, "Michael A. Terrell" <mike.terr...@earthlink.net>
wrote:
> Charles wrote:
>
> > "Michael A. Terrell" wrote in message
> >news:Q5-dnb6L_OTrdvjTnZ2dnUVZ_vKdnZ2d@earthlink.com...
>
> > Charles wrote:
>
> > > It would be a real blast to see all of the posers in one or more of these
> > > arenas:
>
> > > 4/ Street in an Atlanta ghetto
>
> > Why would we want to visit you, in your ghetto? Roy J Quijano of
> > Bronx, Ny. has been making death threats for years. It doesn't surprise
> > me that you are interested in his mindless rants and threats.
>
> > --
> > You can't have a sense of humor, if you have no sense.
>
> > Ahem! Sense? I was suggesting other, perhaps more fitting, venues for this
> > crap. Do you have any sense, as in common sense?
>
> Yawn. Go complain about cheap TV speakers again. We're still
> laughing at you over that one, because it shows that you not only have
> no sense, but you've never had any.
>
> --
> You can't have a sense of humor, if you have no sense.

YOU DO NOT VOICE THIS GROUPS STATE OF MIND.
NO ONE IS HERE TO LAUGH AT ANYONE ELSE, YOU CREEPY LOW LIFE.
YOU DONT EVEN HAVE A LEGITIMATE REASON TO VIEW THIS GROUP YOU HACK.
BUZZ OFF OR DIE FREAK-O AND SAVE THE TAXPAYERS THE GRIEF & EXPENDITURE
YOU CAUSE.
PATECUM
TGITM

== 8 of 8 ==
Date: Wed, Sep 7 2011 3:17 am
From: The Ghost In The Machine

THIS FREAKING BUMB SHOULDNT EVEN BE ALLOWED TO POST HERE.
"Michael A. Terrell" <mike.terr...@earthlink.net>

NO PROFILE, NO MEMBERSHIP, HE'S JUST A BIG NOTHING WITH A LOAD OF
NOTHING TO SHARE.

I SAY, BAN THE BUMB!

TGITM
PAT ECUM

==============================================================================
TOPIC: tv vertical deflection problem MAGNUM PT2 chassis
http://groups.google.com/group/sci.electronics.repair/t/1246eff36200b901?hl=en
==============================================================================

== 1 of 2 ==
Date: Tues, Sep 6 2011 6:14 am
From: chuck

On Sun, 4 Sep 2011 10:57:44 -0700 (PDT), b <reverend_rogers@yahoo.com>
wrote:

>Should have been an easy repair, this.
>TV is a mid 90s MAGNUM 5520 VT, PT2 CHASSIS . A supermarket (german
>Aldi) special I believe.
>It came to me a couple of years ago with sound but no picture.
>Increasing g2 gave thin horizontal line, frame collapse.
>
>changed the IC, a new TDA 3653B (which is now fitted.)
>checked/replaced all the components in the supply to the frame chip
>(TDA 3653B). +26V rock solid on pin 6 and 9.
>
>(FYI;: frame chip data: http://www.datasheetcatalog.com/datasheets_pdf/T/D/A/3/TDA3653B.shtml
>TV PT2 schematic : http://www.eserviceinfo.com/downloadsm/41457/_Magnum.html
>)
>
>the problem is still the same. checked key resistors near IC, all in
>spec.
>now , question is how to check for vertical impulses without a scope.
>It could also be the new IC was duff, but will pursue other avenues
>first. I am also beginning to think that last time I opned this et 2
>yrs or more ago, I may have put in a TDA 3653B in place of a TDA 3653
>- not sure what was originally there and I may have got paranoid, not
>sure how critical this is anyway.
> In any case, the tv schematic and the TDA 3653B do not seem to tally
>too closely re: pinouts.
>
>would appreciate any ideas.
>reards, B

Check or replace electrolytic capacitors in the vertical circuit.
Chuck

== 2 of 2 ==
Date: Tues, Sep 6 2011 1:54 pm
From: "chris"

Bad joint going to the yoke ?

"b" wrote in message
news:064ceb80-aa5b-4959-bb6a-d750b35fab70@m18g2000vbe.googlegroups.com...

Should have been an easy repair, this.
TV is a mid 90s MAGNUM 5520 VT, PT2 CHASSIS . A supermarket (german
Aldi) special I believe.
It came to me a couple of years ago with sound but no picture.
Increasing g2 gave thin horizontal line, frame collapse.

changed the IC, a new TDA 3653B (which is now fitted.)
checked/replaced all the components in the supply to the frame chip
(TDA 3653B). +26V rock solid on pin 6 and 9.

(FYI;: frame chip data:
http://www.datasheetcatalog.com/datasheets_pdf/T/D/A/3/TDA3653B.shtml
TV PT2 schematic : http://www.eserviceinfo.com/downloadsm/41457/_Magnum.html
)

the problem is still the same. checked key resistors near IC, all in
spec.
now , question is how to check for vertical impulses without a scope.
It could also be the new IC was duff, but will pursue other avenues
first. I am also beginning to think that last time I opned this et 2
yrs or more ago, I may have put in a TDA 3653B in place of a TDA 3653
- not sure what was originally there and I may have got paranoid, not
sure how critical this is anyway.
In any case, the tv schematic and the TDA 3653B do not seem to tally
too closely re: pinouts.

would appreciate any ideas.
reards, B

==============================================================================
TOPIC: Tips How to Reinstall P4 CPU & Heat Sink or Separate P4 CPU from Heat
Sink?
http://groups.google.com/group/sci.electronics.repair/t/707e8e7589f93af2?hl=en
==============================================================================

== 1 of 2 ==
Date: Tues, Sep 6 2011 8:28 am
From: KenO

Have a Dell 2350 that removed the P4 CPU & Heat Sink. Thought they
would easily separate but did not and both came off together with the
CPU lever locked.

Have not figured out how to reinstall with the CPU lever locked and am
unable to easily separate so I can reinstall the normal way.

As a result I am very interested in any tips to either reinstall a P4
CPU & Heat Sink as one unit or how to easily separate them so the CPU
can be installed first and then install the Heat Sink.

Thanks

Ken

== 2 of 2 ==
Date: Tues, Sep 6 2011 9:07 am
From: stratus46@yahoo.com

On Sep 6, 8:28 am, KenO <kenithol...@yahoo.com> wrote:
> Have a Dell 2350 that removed the P4 CPU & Heat Sink. Thought
they
> would easily separate but did not and both came off together with
the
> CPU lever locked.
>
> Have not figured out how to reinstall with the CPU lever locked and
am
> unable to easily separate so I can reinstall the normal way.
>
> As a result I am very interested in any tips to either reinstall a
P4
> CPU & Heat Sink as one unit or how to easily separate them so the
CPU
> can be installed first and then install the Heat Sink.
>
> Thanks
>
> Ken

You have no choice but to separate the heat sink and processor so you
can release the lock lever on the socket. I would warm the heat sink
up with a hair dryer which will likely soften up the thermal
'adhesive' so yo can pry it apart. It is IMPERATIVE that you do not
put any force between any layers of the processor as that will
destroy it. An Xacto knife or razor blade between the processor top
and the heat sink can crack it loose. Clean off the residue and use
heat sink grease (arctic silver if you have OCD) on the processor. BTW
why did you want to pull the heat sink? I have removed heat sinks more
times than I can remember usually for installing a faster processor.
When I release the heat sink retainer clamp I rotate the heat sink a
little to get it loose as the thermal pad on the sink can be a little
stubborn. Since I have OCD I use arctic silver.

G²

==============================================================================
TOPIC: RCA 25" TV Dead After Power Outage
http://groups.google.com/group/sci.electronics.repair/t/9cec8b76ea358356?hl=en
==============================================================================

== 1 of 2 ==
Date: Tues, Sep 6 2011 10:45 am
From: Greg

Gentlemen,

I have a 25" RCA TV, model #F25651BL / Chassis #CTC177AG. After a power outage
due to a thunderstorm, my set is now completely dead. It was plugged
in but not on at the time.
I don't hear the usual "power up" sound when I plug it in. The fuse
checked OK and nothing looks like it's been burnt or overheated. I
suspect an open somewhere in the power supply, but as I have neither
the tools or knowledge to go further, I'm taking it in for service.
What do you think the problem might be? Could a power surge have
damaged something?

Thanks!
Greg

== 2 of 2 ==
Date: Tues, Sep 6 2011 3:02 pm
From: Meat Plow

On Tue, 06 Sep 2011 13:45:31 -0400, Greg wrote:

> Gentlemen,
>
> I have a 25" RCA TV, model #F25651BL / Chassis #CTC177AG. After a power
> outage due to a thunderstorm, my set is now completely dead. It was
> plugged in but not on at the time.
> I don't hear the usual "power up" sound when I plug it in. The fuse
> checked OK and nothing looks like it's been burnt or overheated. I
> suspect an open somewhere in the power supply, but as I have neither the
> tools or knowledge to go further, I'm taking it in for service. What do
> you think the problem might be? Could a power surge have damaged
> something?
>
> Thanks!
> Greg

Yup.

--
Live Fast Die Young, Leave A Pretty Corpse

==============================================================================
TOPIC: LCD TV backlight stays on
http://groups.google.com/group/sci.electronics.repair/t/4bf02fb652a75fcf?hl=en
==============================================================================

== 1 of 3 ==
Date: Tues, Sep 6 2011 1:59 pm
From: JK

When the set is powered-off, the backlight on my 5-year old 19" Westinghouse
(LTV-19w6) LCD TV no longer shuts-off.

When the set is unplugged, the backlight (of course) shuts-off. It stays off
when plugged back in.

It's probably a component failure and not worth fixing.

But, perhaps it's a simple software issue... does anyone know how to access
this sets "service adjustment mode"? -- assuming it has one.

Thanks for any info!

== 2 of 3 ==
Date: Tues, Sep 6 2011 1:18 pm
From: Jamie

JK wrote:

> When the set is powered-off, the backlight on my 5-year old 19" Westinghouse
> (LTV-19w6) LCD TV no longer shuts-off.
>
> When the set is unplugged, the backlight (of course) shuts-off. It stays off
> when plugged back in.
>
> It's probably a component failure and not worth fixing.
>
> But, perhaps it's a simple software issue... does anyone know how to access
> this sets "service adjustment mode"? -- assuming it has one.
>
> Thanks for any info!
>
> .
Do you hear a relay drop out when you pull the plug? If so, you have a
leaky transistor or circuit around it has a failure to not fully turn
off the power relay.

Jamie

== 3 of 3 ==
Date: Tues, Sep 6 2011 3:06 pm
From: Meat Plow

On Tue, 06 Sep 2011 15:59:25 -0500, JK wrote:

> When the set is powered-off, the backlight on my 5-year old 19"
> Westinghouse (LTV-19w6) LCD TV no longer shuts-off.
>
> When the set is unplugged, the backlight (of course) shuts-off. It
> stays off when plugged back in.
>
> It's probably a component failure and not worth fixing.
>
> But, perhaps it's a simple software issue... does anyone know how to
> access this sets "service adjustment mode"? -- assuming it has one.
>
> Thanks for any info!
>
> .

Have a Dell 19" monitor that does the same thing. We just unplug it and
then plug it back in and the backlight remains off. I'm not going to fuck
with it, it's 7 years old and will be replaced but kept as a spare.

--
Live Fast Die Young, Leave A Pretty Corpse

==============================================================================
TOPIC: OT: exploring inside an LCD backlight area
http://groups.google.com/group/sci.electronics.repair/t/0a88475fdf40fbd1?hl=en
==============================================================================

== 1 of 3 ==
Date: Tues, Sep 6 2011 1:39 pm
From: "hrhofmann@att.net"

On Sep 5, 3:17 am, "N_Cook" <dive...@tcp.co.uk> wrote:
> For a laptop if different in a TV. Is there a specific name for those sheets
> of diffuser/refractor plastic. Look like a conflation of "straightened"
> Fresnel lens and stationary image of TV picture noise but semirandom under
> x30 viewing. I've never understood why no apparent unevenness of
> illumination over the height of the screen and still don't see why that is .
> Something to do with , in this case, 3 sheets of different grades and
> thickness of diffussion sheet?. Also anyone know how much shorter a light
> tube replacement you can get away with before the edges of the screen become
> a/ unviewable , b/ noticeably less lit as a band at screen edges

I have the same questions. It is amazig how they can take an uneven
source and make it into a (almost) completely even background. I hope
someone has a patent on the idea.

== 2 of 3 ==
Date: Wed, Sep 7 2011 12:46 am
From: "N_Cook"

<hrhofmann@att.net> wrote in message
news:eefe9316-f146-4e69-b58f-d85c8c14d4ee@en1g2000vbb.googlegroups.com...
On Sep 5, 3:17 am, "N_Cook" <dive...@tcp.co.uk> wrote:
> For a laptop if different in a TV. Is there a specific name for those
sheets
> of diffuser/refractor plastic. Look like a conflation of "straightened"
> Fresnel lens and stationary image of TV picture noise but semirandom under
> x30 viewing. I've never understood why no apparent unevenness of
> illumination over the height of the screen and still don't see why that is
.
> Something to do with , in this case, 3 sheets of different grades and
> thickness of diffussion sheet?. Also anyone know how much shorter a light
> tube replacement you can get away with before the edges of the screen
become
> a/ unviewable , b/ noticeably less lit as a band at screen edges

I have the same questions. It is amazig how they can take an uneven
source and make it into a (almost) completely even background. I hope
someone has a patent on the idea.

&&&&&

Is it the same structure in LCD TVs ? Is it ust a lamp on each side giving
the central area the same illumination as at a side or the top or bottom of
a 4 foot or more screen. ?

== 3 of 3 ==
Date: Wed, Sep 7 2011 3:08 am
From: "Wild_Bill"

You may already realize that newer models utilize LEDs, although I haven't
actually had one of 'em apart.

I have some Sony FDL-X600 6" LCD video monitors which use a bent FL tube
behind the white layer, instead of along the sides.
The tube goes back ' forth widthwise with three 180 degree bends.. I don't
know if there would be a way to improvise the single lamp with several
smaller ones.
These monitors have some advanced features that most LCD units don't have,
such as a knob adjustment which electronically (not mechanically) improves
the image at different viewing angles, and switching for color temperature
in addition to the regularly included brightness, contrast, color and tint.

I generally like the display of LCDs for color and brightness, but watching
fast motion is bad on the cheap 22" Coby that I watch sometimes.

For computer monitors, LCDs are hard to beat for compactness and cooler
operating temperatures.

I don't know the special characteristics of the layers of diffusers used
behind LCDs, but I can notice a slightly darker band in the center of the
Coby, but only when the entire screen is at a black level (no video
displayed).. otherwise, it's not noticeable.

--
Cheers,
WB
.............

"N_Cook" <diverse@tcp.co.uk> wrote in message
news:j420do$rdo$1@dont-email.me...
> For a laptop if different in a TV. Is there a specific name for those
> sheets
> of diffuser/refractor plastic. Look like a conflation of "straightened"
> Fresnel lens and stationary image of TV picture noise but semirandom under
> x30 viewing. I've never understood why no apparent unevenness of
> illumination over the height of the screen and still don't see why that is
> .
> Something to do with , in this case, 3 sheets of different grades and
> thickness of diffussion sheet?. Also anyone know how much shorter a light
> tube replacement you can get away with before the edges of the screen
> become
> a/ unviewable , b/ noticeably less lit as a band at screen edges
>
>

==============================================================================
TOPIC: WHO IS JESUS ?????????
http://groups.google.com/group/sci.electronics.repair/t/9f51af72f44a3e39?hl=en
==============================================================================

== 1 of 1 ==
Date: Tues, Sep 6 2011 2:18 pm
From: "Charles"

Absolutely nothing. And for those of us that may have missed the spam
the first time, you reposted the entire thing not once, but twice.

Exactly! A usenet license should be required (or perhaps an IQ
certificate).

==============================================================================
TOPIC: ELECTRONICS REPAIR
http://groups.google.com/group/sci.electronics.repair/t/182d281cbae6a5e7?hl=en
==============================================================================

== 1 of 1 ==
Date: Tues, Sep 6 2011 8:14 pm
From: anbu

http://123maza.com/65/cute540/

==============================================================================
TOPIC: ELECTRONICS REPAIR PROBLM SOLVING MATHOD
http://groups.google.com/group/sci.electronics.repair/t/5aa00cfd22c7e05d?hl=en
==============================================================================

== 1 of 2 ==
Date: Tues, Sep 6 2011 8:27 pm
From: anbu

http://123maza.com/65/cute540/

== 2 of 2 ==
Date: Wed, Sep 7 2011 7:26 am
From: Evan Platt

On Tue, 6 Sep 2011 20:27:13 -0700 (PDT), anbu <anbumani923@gmail.com>
wrote:

My God, where did you learn to spell, idiot spammer?
--
To reply via e-mail, remove The Obvious and .invalid from my e-mail address.

==============================================================================
TOPIC: Contactor coil: 50 Hz vs. 60 Hz
http://groups.google.com/group/sci.electronics.repair/t/0d1a06068779ce43?hl=en
==============================================================================

== 1 of 2 ==
Date: Wed, Sep 7 2011 10:12 am
From: ehsjr

NT wrote:
> On Sep 2, 8:41 pm, John Fields <jfie...@austininstruments.com> wrote:
>
>>Snipped a lot of repetitious, self serving nonsense.
>>
>>
>>>>>>and if the relay is
>>>>>>designed to operate on AC with a certain RMS current in its coil, how
>>>>>>can it possibly overheat if that current is DC?
>>
>>>>>With the same current it wont, with higher curren ti will. IIRC you
>>>>>proposed using 174v rms,
>>
>>>>No, I merely added a capacitor across the output of _your_ proposed
>>>>full wave rectified 120 VRMS 60Hz source (170V peak) in order to get
>>>>smoothed DC closer to the relay's must-make current.
>>
>>>fwliw I said use diodes, you came back with a FW BR. I dont think it
>>>matters.
>>
>>---
>>Then show me your circuit.
>>
>>Just in case you've forgotten, your suggestion was to use a 240V AC
>>relay using diodes and 120V mains.
>>---
>>
>>
>>>>>that would be ok on your specific relay, but
>>>>>not a universal solution.
>>
>>>>???
>>
>>>Your proposd BR+C delivers the right i for one specific relay. For
>>>some relays it will fry them.
>>
>>---
>>Show me.
>
>
> If you want to go get some specs of other relays, you can. This is
> starting to get silly.

Worth investigating, to me. JF gave a specific relay & numbers. I
tried to find a relay to support the idea that an AC/DC relay would
be happy with DC voltage about 50% of AC rating. Can you please
provide a reference?

Meanwhile, what I did find was an ap note from Tyco entitled
"Operating DC Relays from AC and Vice-Versa" .
http://relays.te.com/appnotes/app_pdfs/13c3250.pdf

It does not agree with the DC at ~50% of AC rating idea. It uses
the example of a KR series relay coil. Their example uses a 12
volt AC relay fed by DC. The example states that the "DC voltage
cannot exceed 9.8 volts", and "should not be lower than 7.35 volts".
Thus the DC range would be ~61%(minimum) to ~81% (maximum) of the
12VAC rating.

Extrapolating, it does agree with the idea of BR+C fed by 120 for
the 240 volt relay, insofar as the DC voltage:
~146VDC min to ~194VDC max, which makes the midpoint ~170VDC.
That's very close to ~168 from the BR+C

Regarding coil ratings, I've worked with DC relays, and I've worked
with AC relays, but I haven't worked with AC/DC coil relays, so
I can't speak from experience with them, and I haven't found
anything yet specifically dealing with that, other than the
link I found to Tyco. So a specific link or links would be
most helpful.

Thanks,
Ed

== 2 of 2 ==
Date: Wed, Sep 7 2011 10:33 am
From: Jamie

ehsjr wrote:
> NT wrote:
>
>> On Sep 2, 8:41 pm, John Fields <jfie...@austininstruments.com> wrote:
>>
>>> Snipped a lot of repetitious, self serving nonsense.
>>>
>>>
>>>>>>> and if the relay is
>>>>>>> designed to operate on AC with a certain RMS current in its coil,
>>>>>>> how
>>>>>>> can it possibly overheat if that current is DC?
>>>
>>>
>>>>>> With the same current it wont, with higher curren ti will. IIRC you
>>>>>> proposed using 174v rms,
>>>
>>>
>>>>> No, I merely added a capacitor across the output of _your_ proposed
>>>>> full wave rectified 120 VRMS 60Hz source (170V peak) in order to get
>>>>> smoothed DC closer to the relay's must-make current.
>>>
>>>
>>>> fwliw I said use diodes, you came back with a FW BR. I dont think it
>>>> matters.
>>>
>>>
>>> ---
>>> Then show me your circuit.
>>>
>>> Just in case you've forgotten, your suggestion was to use a 240V AC
>>> relay using diodes and 120V mains.
>>> ---
>>>
>>>
>>>>>> that would be ok on your specific relay, but
>>>>>> not a universal solution.
>>>
>>>
>>>>> ???
>>>
>>>
>>>> Your proposd BR+C delivers the right i for one specific relay. For
>>>> some relays it will fry them.
>>>
>>>
>>> ---
>>> Show me.
>>
>>
>>
>> If you want to go get some specs of other relays, you can. This is
>> starting to get silly.
>
>
> Worth investigating, to me. JF gave a specific relay & numbers. I
> tried to find a relay to support the idea that an AC/DC relay would
> be happy with DC voltage about 50% of AC rating. Can you please
> provide a reference?
>
> Meanwhile, what I did find was an ap note from Tyco entitled
> "Operating DC Relays from AC and Vice-Versa" .
> http://relays.te.com/appnotes/app_pdfs/13c3250.pdf
>
> It does not agree with the DC at ~50% of AC rating idea. It uses
> the example of a KR series relay coil. Their example uses a 12
> volt AC relay fed by DC. The example states that the "DC voltage
> cannot exceed 9.8 volts", and "should not be lower than 7.35 volts".
> Thus the DC range would be ~61%(minimum) to ~81% (maximum) of the
> 12VAC rating.
>
> Extrapolating, it does agree with the idea of BR+C fed by 120 for
> the 240 volt relay, insofar as the DC voltage:
> ~146VDC min to ~194VDC max, which makes the midpoint ~170VDC.
> That's very close to ~168 from the BR+C
>
> Regarding coil ratings, I've worked with DC relays, and I've worked
> with AC relays, but I haven't worked with AC/DC coil relays, so
> I can't speak from experience with them, and I haven't found
> anything yet specifically dealing with that, other than the
> link I found to Tyco. So a specific link or links would be
> most helpful.
>
> Thanks,
> Ed
You must remember that AC coil relays are wound a little different,
its not just induction here. Inter pole windings help keep the AC coil
from chattering the armature. I am sure under DC operation, this may
effect the calculations.

There are some AC coil relays that do not do this and thus the 50%
voltage for DC should come close, but then again, DC R in the coil also
plays a role in this.

Jamie

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