sci.electronics.repair@googlegroups.com

Today's topics:

* Toshiba motor control IC - 1 messages, 1 author
http://groups.google.com/group/sci.electronics.repair/t/7c9468d70d38e98e?hl=en
* computer problems - 6 messages, 5 authors
http://groups.google.com/group/sci.electronics.repair/t/d5b26a3411c63324?hl=en
* Re-winding solenoids. - 19 messages, 6 authors
http://groups.google.com/group/sci.electronics.repair/t/fd7d7813745e3da8?hl=en

==============================================================================
TOPIC: Toshiba motor control IC
http://groups.google.com/group/sci.electronics.repair/t/7c9468d70d38e98e?hl=en
==============================================================================

== 1 of 1 ==
Date: Sun, Oct 16 2011 2:00 pm
From: "news@rblack01.plus.com"

On Oct 16, 9:33 pm, Jamie
<jamie_ka1lpa_not_valid_after_ka1l...@charter.net> wrote:
> n...@rblack01.plus.com wrote:
> > Hi,
>
> > Can anyone help identify a Toshiba IC used for bidirectional control
> > of a brushed motor?  The original part number is partially missing as
> > the chip has a crater blown in the package when the mechanism
> > seized...
>
> > 12-pin staggered SIL package, with metal heatsink tab
> > Legend says TOSHIBA, part number begins TA80
>
> > The IC is part of the controller for the power antenna in a 1998 Mazda
> > 323F (known as a Miata in North America I believe).  Toshiba don't
> > list anything similar in their current line-up, so I'm assuming the IC
> > is EOL and I'm looking at obsolete parts suppliers.
>
> > If anyone can identify this chip and, better still, point me to a
> > datasheet, I might be able to find a similar part or lash something up
> > using discretes if I can't locate a replacement.
>
> > TIA
>
> > R.
>
> Does this help?
>
> http://pdf1.alldatasheet.com/datasheet-pdf/view/31395/TOSHIBA/TA8051P...
>
> YOu can use a dual channel power amp IC, found in basic medium power
> stereos for this. Or just fab a bridge from some power fets.
>
> Jamie

Excellent, thanks very much for that. I'll trace the circuit tomorrow
and check the pin functions match. Agreed, lots of other bridge chips
will do as a substitute but I'll try a few of the local obsolete
component specialists first.

Cheers

R.

==============================================================================
TOPIC: computer problems
http://groups.google.com/group/sci.electronics.repair/t/d5b26a3411c63324?hl=en
==============================================================================

== 1 of 6 ==
Date: Sun, Oct 16 2011 2:15 pm
From: Franc Zabkar

On Sun, 16 Oct 2011 10:16:51 -0700 (PDT), klem kedidelhopper
<captainvideo462009@gmail.com> put finger to keyboard and composed:

>My son suggested a possible "bios virus". I had
>no idea that such a thing was possible.

Here is one well-known example:
http://en.wikipedia.org/wiki/CIH_(computer_virus)

"CIH, also known as Chernobyl or Spacefiller, is a Microsoft Windows
computer virus written by Chen Ing Hau of Taiwan. It is one of the
most damaging viruses, overwriting critical information on infected
system drives, and more importantly, in some cases corrupting the
system BIOS."

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

== 2 of 6 ==
Date: Sun, Oct 16 2011 3:16 pm
From: whit3rd

Your computer booted into an unfamiliar operating system,
and you were seeing lots of the normal boot things on-screen
BECAUSE THE OS DOES THAT. Nothing wrong with the BIOS.

It's just a matter of booting from something (floppy, CD)
other than the 'unknown' system, then all will look normal.
Some BIOS'es are hard to enter at boot time (there's a few
seconds when they look for a keyboard entry, otherwise
it just boots up fast from the hard disk).

The good news, is that the boot process DID happen from
the unknown drive, even though it looked odd on your screen
(probably your computer had the wrong hardware to satisfy the
boot-time sequence on that hard drive). Maybe the
screen gibberish means the video card driver was not
autoidentified, and the freeze was because you didn't log in.

== 3 of 6 ==
Date: Sun, Oct 16 2011 3:22 pm
From: Jeff Liebermann

On Sun, 16 Oct 2011 10:16:51 -0700 (PDT), klem kedidelhopper
<captainvideo462009@gmail.com> wrote:

>I really hope that someone can help me with this. I have a P233 with
>American Megatrends

Ancient MB. Get something up to date.

My guess(tm) is that your BIOS and MB are fine. What you probably did
is connect the 2nd hard disk to the first IDE cable, without setting
the jumpers on either your original drive, or the used drive. The
result is that it won't boot. In that state, it will also fail to
display the BIOS screen, as it will be waiting a long time (about 5
minutes) for the drives to come ready, before showing the BIOS. Your
description would be more useful if you would describe what actually
happens when you turn on the machine, rather than what doesn't happen
(i.e. doesn't boot, won't show BIOS, etc).

Also, reversing the ribbon cable connections to the drives are
possible. In some really early machines, that would blow up the IDE
controller on the motherboard. If the drive is really mangled, with a
short between the +5V and +12V lines, it's likely that you just
applied +12V to the motherboard +5V bus, which tends to blow things
up.

If you want to continue this excercise, be sure that your main drive
is backed up. Also, either use the 2nd IDE controller and cable to
test drives, or do what I do, which is to use a USB to IDE cable, and
format it via the USB port. They're about $5 on eBay. Plan on
blowing up a few of them as drives with a short between the +12v and
+5v are likely to blow up the adapter.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

== 4 of 6 ==
Date: Sun, Oct 16 2011 4:02 pm
From: klem kedidelhopper

On Oct 16, 6:22 pm, Jeff Liebermann <je...@cruzio.com> wrote:
> On Sun, 16 Oct 2011 10:16:51 -0700 (PDT), klem kedidelhopper
>
> <captainvideo462...@gmail.com> wrote:
> >I really hope that someone can help me with this. I have a P233 with
> >American Megatrends  
>
> Ancient MB.  Get something up to date.
>
> My guess(tm) is that your BIOS and MB are fine.  What you probably did
> is connect the 2nd hard disk to the first IDE cable, without setting
> the jumpers on either your original drive, or the used drive.  The
> result is that it won't boot.  In that state, it will also fail to
> display the BIOS screen, as it will be waiting a long time (about 5
> minutes) for the drives to come ready, before showing the BIOS.  Your
> description would be more useful if you would describe what actually
> happens when you turn on the machine, rather than what doesn't happen
> (i.e. doesn't boot, won't show BIOS, etc).
>
> Also, reversing the ribbon cable connections to the drives are
> possible.  In some really early machines, that would blow up the IDE
> controller on the motherboard.  If the drive is really mangled, with a
> short between the +5V and +12V lines, it's likely that you just
> applied +12V to the motherboard +5V bus, which tends to blow things
> up.
>
> If you want to continue this excercise, be sure that your main drive
> is backed up.  Also, either use the 2nd IDE controller and cable to
> test drives, or do what I do, which is to use a USB to IDE cable, and
> format it via the USB port.  They're about $5 on eBay.  Plan on
> blowing up a few of them as drives with a short between the +12v and
> +5v are likely to blow up the adapter.
>
> --
> Jeff Liebermann     je...@cruzio.com
> 150 Felker St #D    http://www.LearnByDestroying.com
> Santa Cruz CA 95060http://802.11junk.com
> Skype: JeffLiebermann     AE6KS    831-336-2558

Right now there is no drive in the machine. I'm just trying to see if
I can go through post. The "'drive seek" doesn't seem to happen either
so "A" drive is not happening during the boot attempt. If I can just
get into bios again I would try to select that from the advanced menu
and see if it makes a difference. If I can get to an "A" prompt on a
diskette with Format and F disk on it perhaps I'll have a shot... Lenny

== 5 of 6 ==
Date: Sun, Oct 16 2011 4:46 pm
From: Jeff Liebermann

On Sun, 16 Oct 2011 16:02:29 -0700 (PDT), klem kedidelhopper
<captainvideo462009@gmail.com> wrote:

>Right now there is no drive in the machine.

Remove CMOS battery to reset everything. You may need to also
temporarily move a jumper to do the CMOS reset.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

== 6 of 6 ==
Date: Sun, Oct 16 2011 5:22 pm
From: "William Sommerwerck"

I was going to keep my nose out of this, but I'm so thoroughly confused that
I have to butt in.

What are you trying to do? Test the drives? If so, this seems about the
worst possible way. It would make more sense to set these drives as slaves
and boot them on a known-good computer (as someone else suggested). Even
better, if they're IDE-ATA drives, you can mount them in a box with a USB
interface, and simply attach them to a running machine.

What is the question you're asking? I suspect it's the wrong one.

==============================================================================
TOPIC: Re-winding solenoids.
http://groups.google.com/group/sci.electronics.repair/t/fd7d7813745e3da8?hl=en
==============================================================================

== 1 of 19 ==
Date: Sun, Oct 16 2011 2:33 pm
From: Jamie

Jeffrey Angus wrote:

> Just a few abstract thoughts here. It makes sense to me,
> but then I've been known to over look the obvious on
> occasion. ;-)
>
> I have a solenoid coil that actuates a large 3-pole
> contactor. A short pulse to pull up on a lever that
> will toggle it from on position to another, and back.
>
> Making measurements of the solenoid coil, although
> potted in epoxy, yields a few measurements and a
> couple of guesses.
>
> <http://www.pronine.ca/multind.htm>
>
> Coil form 1" diameter, 1-3/8" width and 1.5" depth.
> Going backwards on a solenoid coil java script, yields
> a matching 125 mH inductance (as measured) and 95 ohm
> DCR (as measured) for 2500 turns of #30 AWG which will
> fill the bobbin.
>
> This a 480 VAC actuator.
>
> Am I headed in the right direction if I assume the key
> factor here is ampere turns?
>
> Not allowing for the added inductance by a movable core,
> this has an impedance of roughly 100 ohms. So that works
> out to 4.8 amps or 12,000 ampere turns.
>
> Substituting 2000 turns of #28 AWG yields 80 mH, and 42
> Ohms. And subsequently roughly 12,000 ampere turns at
> 240 VAC.
>
> Putting 240 VAC across the 480 VAC coil yields only 6,000
> ampere turns and obviously is NOT enough to actuate the
> contactor transfer mechanism.
>
> The reason I'm curious is that ASCO seems to think that
> the replacement coil for this is worth $585, although
> they will sell it as the "sale price" of only $421.80.
>
> Jeff-1.0
> The other other one
>
Beware that some coils are dual coils with diodes potted in them.

WHen a diode fails in one of these, they tend to generate some noise
when energized. This is because one coil is pushing both directions
against the other that isn't.

Basically what this means is, the coil is designed to operate in a
DC state.

What we have done in the past if we suspected a shorted diode in one
of these types is to put a bridge rectifier in front of it.

But I can tell you this, if the construction of core around this coil
in the device that is using it has a laminated type layers, chances are,
you have a simple coil and there is some form of shading device near the
contact point where the accouter makes contact with it.

What is this thing? A ratcheting three position device? being ASCO, it
sounds like some kind of valve.

Jamie

== 2 of 19 ==
Date: Sun, Oct 16 2011 3:14 pm
From: Jeff Liebermann

On Sun, 16 Oct 2011 15:48:07 -0500, Jeffrey Angus <grendelair@aim.com>
wrote:

>This a 480 VAC actuator.

Make, model, and photograph?

Is there a copper D-ring on the top end of the solenoid?

If the coil it dead, try disolving the epoxy.
<http://www.esslinger.com/attack.aspx>
It will also make a useful coil form.

If you know the core dimensions and the wire guage, you can estimate
the number of turns.

>The reason I'm curious is that ASCO seems to think that
>the replacement coil for this is worth $585, although
>they will sell it as the "sale price" of only $421.80.

Check eBay?

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

== 3 of 19 ==
Date: Sun, Oct 16 2011 3:25 pm
From: Jeffrey Angus

On 10/16/2011 4:33 PM, Jamie wrote:
> Beware that some coils are dual coils with diodes potted in them.
>
> WHen a diode fails in one of these, they tend to generate some noise
> when energized. This is because one coil is pushing both directions
> against the other that isn't.
>
> Basically what this means is, the coil is designed to operate in a
> DC state.
>
> What we have done in the past if we suspected a shorted diode in one
> of these types is to put a bridge rectifier in front of it.
>
> But I can tell you this, if the construction of core around this coil
> in the device that is using it has a laminated type layers, chances are,
> you have a simple coil and there is some form of shading device near the
> contact point where the accouter makes contact with it.
>
> What is this thing? A ratcheting three position device? being ASCO, it
> sounds like some kind of valve.

This is a simple multi-layer solenoid.
It is fed with 480 VAC via an external bridge rectifier.

It is a pull up actuated 100 amp 3-pole contactor.

It is physically identical to this one, with the excption of
being 3-poles rather than 2.

<http://www.ebay.com/itm/130520617745>

The solenoid is at the top left of the contactor with the bridge
rectifier on the side.

Jeff-1.0

--
"Everything from Crackers to Coffins"

== 4 of 19 ==
Date: Sun, Oct 16 2011 3:30 pm
From: Jeffrey Angus

On 10/16/2011 5:14 PM, Jeff Liebermann wrote:
> On Sun, 16 Oct 2011 15:48:07 -0500, Jeffrey Angus<grendelair@aim.com>
> wrote:
>
>> This a 480 VAC actuator.
>
> Make, model, and photograph?

A similar model. 2-pole 120 VAC rather than 3-pole 480 VAC.
<http://www.ebay.com/itm/130520617745>

This is the coil itself from ASCO.
<http://www.ascoparts.com/343500-063.html>

> Is there a copper D-ring on the top end of the solenoid?

Nope.

> If the coil it dead, try disolving the epoxy.
> <http://www.esslinger.com/attack.aspx>
> It will also make a useful coil form.

Coil works perfectly with 480 VAC applied to the bridge
recitfier. My task is to wind a new coil that will work
at 240 VAC.

> If you know the core dimensions and the wire gauge, you
> can estimate the number of turns.

I did that, see the initial posting. Using DC resistance,
physical size and measured inductance.

>> The reason I'm curious is that ASCO seems to think that
>> the replacement coil for this is worth $585, although
>> they will sell it as the "sale price" of only $421.80.
>
> Check eBay?

They have the contactors available from $750 and up, and
complete units for $1500 and up.

No solenoids only.

Jeff-1.0

--
"Everything from Crackers to Coffins"

== 5 of 19 ==
Date: Sun, Oct 16 2011 3:43 pm
From: spamtrap1888

On Oct 16, 1:48 pm, Jeffrey Angus <grendel...@aim.com> wrote:
> Just a few abstract thoughts here. It makes sense to me,
> but then I've been known to over look the obvious on
> occasion. ;-)
>
> I have a solenoid coil that actuates a large 3-pole
> contactor. A short pulse to pull up on a lever that
> will toggle it from on position to another, and back.
>
> Making measurements of the solenoid coil, although
> potted in epoxy, yields a few measurements and a
> couple of guesses.
>
> <http://www.pronine.ca/multind.htm>
>
> Coil form 1" diameter, 1-3/8" width and 1.5" depth.
> Going backwards on a solenoid coil java script, yields
> a matching 125 mH inductance (as measured) and 95 ohm
> DCR (as measured) for 2500 turns of #30 AWG which will
> fill the bobbin.
>
> This a 480 VAC actuator.
>
> Am I headed in the right direction if I assume the key
> factor here is ampere turns?
>
> Not allowing for the added inductance by a movable core,
> this has an impedance of roughly 100 ohms. So that works
> out to 4.8 amps or 12,000 ampere turns.
>
> Substituting 2000 turns of #28 AWG yields 80 mH, and 42
> Ohms. And subsequently roughly 12,000 ampere turns at
> 240 VAC.
>
> Putting 240 VAC across the 480 VAC coil yields only 6,000
> ampere turns and obviously is NOT enough to actuate the
> contactor transfer mechanism.
>
> The reason I'm curious is that ASCO seems to think that
> the replacement coil for this is worth $585, although
> they will sell it as the "sale price" of only $421.80.

do you see the part number on this list? Seems considerably cheaper:

http://www.valvestore.com/products.asp?dept=1448

== 6 of 19 ==
Date: Sun, Oct 16 2011 6:05 pm
From: Jamie

Jeffrey Angus wrote:

> On 10/16/2011 5:14 PM, Jeff Liebermann wrote:
>
>> On Sun, 16 Oct 2011 15:48:07 -0500, Jeffrey Angus<grendelair@aim.com>
>> wrote:
>>
>>> This a 480 VAC actuator.
>>
>>
>> Make, model, and photograph?
>
>
>
> A similar model. 2-pole 120 VAC rather than 3-pole 480 VAC.
> <http://www.ebay.com/itm/130520617745>
>
> This is the coil itself from ASCO.
> <http://www.ascoparts.com/343500-063.html>
>
>> Is there a copper D-ring on the top end of the solenoid?
>
>
> Nope.
>
>> If the coil it dead, try disolving the epoxy.
>> <http://www.esslinger.com/attack.aspx>
>> It will also make a useful coil form.
>
>
> Coil works perfectly with 480 VAC applied to the bridge
> recitfier. My task is to wind a new coil that will work
> at 240 VAC.
>
>> If you know the core dimensions and the wire gauge, you
>> can estimate the number of turns.
>
>
> I did that, see the initial posting. Using DC resistance,
> physical size and measured inductance.
>
>>> The reason I'm curious is that ASCO seems to think that
>>> the replacement coil for this is worth $585, although
>>> they will sell it as the "sale price" of only $421.80.
>>
>>
>> Check eBay?
>
>
> They have the contactors available from $750 and up, and
> complete units for $1500 and up.
>
> No solenoids only.
>
> Jeff-1.0
>
>
>
Why don't you use a simple step up transformer for the coil?
you won't need a large one.

JAmie

== 7 of 19 ==
Date: Sun, Oct 16 2011 6:12 pm
From: Jamie

Jamie wrote:

> Jeffrey Angus wrote:
>
>> On 10/16/2011 5:14 PM, Jeff Liebermann wrote:
>>
>>> On Sun, 16 Oct 2011 15:48:07 -0500, Jeffrey Angus<grendelair@aim.com>
>>> wrote:
>>>
>>>> This a 480 VAC actuator.
>>>
>>>
>>>
>>> Make, model, and photograph?
>>
>>
>>
>>
>> A similar model. 2-pole 120 VAC rather than 3-pole 480 VAC.
>> <http://www.ebay.com/itm/130520617745>
>>
>> This is the coil itself from ASCO.
>> <http://www.ascoparts.com/343500-063.html>
>>
>>> Is there a copper D-ring on the top end of the solenoid?
>>
>>
>>
>> Nope.
>>
>>> If the coil it dead, try disolving the epoxy.
>>> <http://www.esslinger.com/attack.aspx>
>>> It will also make a useful coil form.
>>
>>
>>
>> Coil works perfectly with 480 VAC applied to the bridge
>> recitfier. My task is to wind a new coil that will work
>> at 240 VAC.
>>
>>> If you know the core dimensions and the wire gauge, you
>>> can estimate the number of turns.
>>
>>
>>
>> I did that, see the initial posting. Using DC resistance,
>> physical size and measured inductance.
>>
>>>> The reason I'm curious is that ASCO seems to think that
>>>> the replacement coil for this is worth $585, although
>>>> they will sell it as the "sale price" of only $421.80.
>>>
>>>
>>>
>>> Check eBay?
>>
>>
>>
>> They have the contactors available from $750 and up, and
>> complete units for $1500 and up.
>>
>> No solenoids only.
>>
>> Jeff-1.0
>>
>>
>>
> Why don't you use a simple step up transformer for the coil?
> you won't need a large one.
>
> JAmie
>
>
To add to that, a 1:1 control transformer of a very small size can
be wired as a buck boost to operate that coil.

Jamie

== 8 of 19 ==
Date: Sun, Oct 16 2011 6:01 pm
From: "Michael A. Terrell"

Jamie wrote:
>
> Jamie wrote:
>
> > Jeffrey Angus wrote:
> >
> >> On 10/16/2011 5:14 PM, Jeff Liebermann wrote:
> >>
> >>> On Sun, 16 Oct 2011 15:48:07 -0500, Jeffrey Angus<grendelair@aim.com>
> >>> wrote:
> >>>
> >>>> This a 480 VAC actuator.
> >>>
> >>>
> >>>
> >>> Make, model, and photograph?
> >>
> >>
> >>
> >>
> >> A similar model. 2-pole 120 VAC rather than 3-pole 480 VAC.
> >> <http://www.ebay.com/itm/130520617745>
> >>
> >> This is the coil itself from ASCO.
> >> <http://www.ascoparts.com/343500-063.html>
> >>
> >>> Is there a copper D-ring on the top end of the solenoid?
> >>
> >>
> >>
> >> Nope.
> >>
> >>> If the coil it dead, try disolving the epoxy.
> >>> <http://www.esslinger.com/attack.aspx>
> >>> It will also make a useful coil form.
> >>
> >>
> >>
> >> Coil works perfectly with 480 VAC applied to the bridge
> >> recitfier. My task is to wind a new coil that will work
> >> at 240 VAC.
> >>
> >>> If you know the core dimensions and the wire gauge, you
> >>> can estimate the number of turns.
> >>
> >>
> >>
> >> I did that, see the initial posting. Using DC resistance,
> >> physical size and measured inductance.
> >>
> >>>> The reason I'm curious is that ASCO seems to think that
> >>>> the replacement coil for this is worth $585, although
> >>>> they will sell it as the "sale price" of only $421.80.
> >>>
> >>>
> >>>
> >>> Check eBay?
> >>
> >>
> >>
> >> They have the contactors available from $750 and up, and
> >> complete units for $1500 and up.
> >>
> >> No solenoids only.
> >>
> >> Jeff-1.0
> >>
> >>
> >>
> > Why don't you use a simple step up transformer for the coil?
> > you won't need a large one.
> >
> > JAmie
> >
> >
> To add to that, a 1:1 control transformer of a very small size can
> be wired as a buck boost to operate that coil.

Tell him something he DOESN'T already know.

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

== 9 of 19 ==
Date: Sun, Oct 16 2011 6:12 pm
From: Jeffrey Angus

On 10/16/2011 8:05 PM, Jamie wrote:
> Why don't you use a simple step up transformer for the coil?
> you won't need a large one.

Um, however briefly, the transformer needs to supply
5.2 amps at 480 volts to successfully energize the coil.

That's 2500 VA Even a 500 VA control transformer that I have
sags too much to properly actuate the transfer switch.

Jeff-1.0

--
"Everything from Crackers to Coffins"

== 10 of 19 ==
Date: Sun, Oct 16 2011 6:19 pm
From: Jeffrey Angus

On 10/16/2011 8:12 PM, Jamie wrote:
> To add to that, a 1:1 control transformer of a very small size
> can be wired as a buck boost to operate that coil.

As I mentioned previously, the solenoid requires a 5.2 amp pulse
to properly actuate the contactor mechanism.

With a 240/240 control transformer wired up in boost mode that
would need at 1000 VA transformer as a bare minimum.

Jeff-1.0

--
"Everything from Crackers to Coffins"

== 11 of 19 ==
Date: Sun, Oct 16 2011 6:34 pm
From: Jamie

Jeffrey Angus wrote:

> On 10/16/2011 8:05 PM, Jamie wrote:
>
>> Why don't you use a simple step up transformer for the coil?
>> you won't need a large one.
>
>
> Um, however briefly, the transformer needs to supply
> 5.2 amps at 480 volts to successfully energize the coil.
>
> That's 2500 VA Even a 500 VA control transformer that I have
> sags too much to properly actuate the transfer switch.
>
> Jeff-1.0
>
I find it hard to believe that coil is using that much? Are you
sure it's in proper working order? We have 500 amp contactors with
120V coils that only require about 2 amps to pull in. Something just
does not sound right, but what ever.

Jamie

== 12 of 19 ==
Date: Sun, Oct 16 2011 6:22 pm
From: Jeffrey Angus

On 10/16/2011 8:01 PM, Michael A. Terrell wrote:
> Tell him something he DOESN'T already know.

Heh, thanks Michael. What I don't know and would like to
know is if my thinking with regards to ampere turns is
correct. Because I CAN wind a new solenoid coil with a
1/2 pound spool of wire for about $20.

Jeff-1.0

--
"Everything from Crackers to Coffins"

== 13 of 19 ==
Date: Sun, Oct 16 2011 6:44 pm
From: Jamie

Jeffrey Angus wrote:

> On 10/16/2011 8:12 PM, Jamie wrote:
>
>> To add to that, a 1:1 control transformer of a very small size
>> can be wired as a buck boost to operate that coil.
>
>
> As I mentioned previously, the solenoid requires a 5.2 amp pulse
> to properly actuate the contactor mechanism.
>
> With a 240/240 control transformer wired up in boost mode that
> would need at 1000 VA transformer as a bare minimum.
>
> Jeff-1.0
>
Then it must be pushing a large load a long distance.

at that current, you looks like you have ~ 100 ohm coil.

which means the wire in the coil is rather a large gauge since
this is DC going to it.

I would start around 20awg and see what the DCR 1M is on the
chart. Then see if that will physically fit on the form.

Jamie.

== 14 of 19 ==
Date: Sun, Oct 16 2011 6:36 pm
From: Jeffrey Angus

On 10/16/2011 8:34 PM, Jamie wrote:
> I find it hard to believe that coil is using that much? Are
> you sure it's in proper working order? We have 500 amp
> contactors with 120V coils that only require about 2 amps
> to pull in. Something just does not sound right, but what
> ever.

Yes I am sure. And yes I know what some contactors take to
actuate the coils in a steady state holding condition.

To repeat. This is a pulsed operation. The auxiliary contacts
on the transfer switch contactor interrupt the source from the
solenoid as it actuates.

The solenoid core pulls up on a link that rotates the armature
of the contactor assembly from normal to emergency position.
Each time it is pulsed, it rotates it one way, then the other
way.

The actual amount of time (I haven't measured it) this takes
is under a second roughly.

Jeff-1.0

--
"Everything from Crackers to Coffins"

== 15 of 19 ==
Date: Sun, Oct 16 2011 6:42 pm
From: "William Sommerwerck"

>> Tell him something he DOESN'T already know.

> Heh, thanks Michael. What I don't know and would like
> to know is if my thinking with regards to ampere turns is
> correct. Because I CAN wind a new solenoid coil with
> a 1/2 pound spool of wire for about $20.

Do you have good reason to believe that AWG 30 is the proper gauge, and that
your calculations are correct? If so, then buy the wire and do it. If it
doesn't work, you're out only $20 and the time it took to wind the coil.

I don't know enough about solenoids to properly judge your calculations. But
I don't see anything obviously wrong.

== 16 of 19 ==
Date: Sun, Oct 16 2011 6:52 pm
From: Jeffrey Angus

On 10/16/2011 8:44 PM, Jamie wrote:
> Then it must be pushing a large load a long distance.
>
> at that current, you looks like you have ~ 100 ohm coil

Did you read the details from my original posting? (Se below)

> which means the wire in the coil is rather a large gauge since
> this is DC going to it.
>
> I would start around 20awg and see what the DCR 1M is on the
> chart. Then see if that will physically fit on the form.

I originally wrote:
> Coil form 1" diameter, 1-3/8" width and 1.5" depth.
> Going backwards on a solenoid coil java script, yields
> a matching 125 mH inductance (as measured) and 95 ohm
> DCR (as measured) for 2500 turns of #30 AWG which will
> fill the bobbin.
>
> This a 480 VAC actuator.

roughly 100 ohms, yes.

This is NOT a constant pull and hold solenoid. This is a
pulsed operation.

> So that works out to 4.8 amps or 12,000 ampere turns.
>
> Substituting 2000 turns of #28 AWG yields 80 mH, and 42
> Ohms. And subsequently roughly 12,000 ampere turns at
> 240 VAC.

Based on: Ampere turns =
(Applied voltage * number of turns)/(coil resistance)

Both estimations of the needed number of turns and wire size
seem correct.

> Putting 240 VAC across the 480 VAC coil yields only 6,000
> ampere turns and obviously is NOT enough to actuate the
> contactor transfer mechanism.

This tends to indicate that ampere turns is indeed the magic
number as 6000 is not enough to actuate a mechanism that
appears to require 12,000.

Jeff-1.0

--
"Everything from Crackers to Coffins"

== 17 of 19 ==
Date: Sun, Oct 16 2011 6:59 pm
From: Jeffrey Angus

On 10/16/2011 8:42 PM, William Sommerwerck wrote:
> Do you have good reason to believe that AWG 30 is the proper
> gauge, and that your calculations are correct?

<http://www.pronine.ca/multind.htm>

Yields both the correct inductance and DC resistance with #30
AWG for the assumptions I've made for the physical size of the
coil bobbin.

> If so, then buy the wire and do it. If it doesn't work, you're
> out only $20 and the time it took to wind the coil.
>
> I don't know enough about solenoids to properly judge your
> calculations. But I don't see anything obviously wrong.

And that's why I thought I'd ask here. I was hoping to find
someone that _is_ familiar enough to at least tell me, "Yeah,
you seem to be heading in the right direction."

Jeff-1.0

--
"Everything from Crackers to Coffins"

== 18 of 19 ==
Date: Sun, Oct 16 2011 9:08 pm
From: spamtrap1888

On Oct 16, 6:59 pm, Jeffrey Angus <grendel...@aim.com> wrote:
> On 10/16/2011 8:42 PM, William Sommerwerck wrote:
>
> > Do you have good reason to believe that AWG 30 is the proper
> > gauge, and that your calculations are correct?
>
> <http://www.pronine.ca/multind.htm>
>
> Yields both the correct inductance and DC resistance with #30
> AWG for the assumptions I've made for the physical size of the
> coil bobbin.
>
> > If so, then buy the wire and do it. If it doesn't work, you're
> > out only $20 and the time it took to wind the coil.
>
> > I don't know enough about solenoids to properly judge your
> > calculations. But I don't see anything obviously wrong.
>
> And that's why I thought I'd ask here. I was hoping to find
> someone that _is_ familiar enough to at least tell me, "Yeah,
> you seem to be heading in the right direction."
>

You didn't say this solenoid was part of a transfer switch. This
raises the stakes substantially. Transfer switches are used to switch
the mains supply to a generator when mains power is interrupted. They
serve two main purposes: to keep critical equipment functioning when
mains power is interrupted, and to deenergize the power line so that
workers can assume it is deenergized when they work on it.

Now, the transfer switch was tested to meet specifications with the
designed solenoid installed. Knowing nothing of the design or
construction of the component, you propose to roll your own and stick
it in.

Which would be fine, if no one's life depended on its working. And if
the vendor would stand behind your handicraft.

I don't think Asco could reasonably foresee that someone would use a
program that gives the number of turns for an air-core inductor to
design a part for a life-safety application.

== 19 of 19 ==
Date: Sun, Oct 16 2011 9:11 pm
From: Jeff Liebermann

On Sun, 16 Oct 2011 17:30:05 -0500, Jeffrey Angus <grendelair@aim.com>
wrote:

>Coil works perfectly with 480 VAC applied to the bridge
>recitfier. My task is to wind a new coil that will work
>at 240 VAC.

You left that out of your initial rant. First sentence should be what
the [deleted expletive] you're trying to accomplish.

>I did that, see the initial posting. Using DC resistance,
>physical size and measured inductance.

What you want is an equal amount of magnetic force (i.e. gilberts) or
ampere-turns for both the 480VAC and 240VAC coils.

480VAC coil = 125mH and 95 ohms
XL = 2*Pi*60*125*10^-3 = 47 ohm
Total impedance is the vector sum of 95 ohms and 47 ohms =
Z = sqrt(95^2 + 47^2) = 105 ohms
Current is:
I = 480VAC / 105 ohms = 4.5A
2500 turns * 4.5A = 11,250 AT
Ok, you got that part correct.

Trying a different gauge for 240VAC. The hard part will be keeping
the max diameter to under 1.5" OD.

<http://www.pronine.ca/multind.htm>
For #29awg, 75mH, 1990 turns, 51 ohms resistance.
XL = 2*Pi*60*75*10^-3 = 28 ohm
Z = sqrt(51^2 + 28^2) = 63 ohms
I = 240VAC / 63 ohms = 3.8A
1990 turns * 3.8A = 7580 AT

For #28awg, 60mH, 1759 turns, 37 ohms resistance.
XL = 2*Pi*60*60*10^-3 = 22.5 ohm
Z = sqrt(51^2 + 37^2) = 63 ohms
I = 240VAC / 63 ohms = 3.8A
1759 turns * 3.8A = 6700 AT

Ok, that's not going to work. Most of the impedance is coming from
the DC resistance of the wire. Decreasing the gauge decreases this
resistance, but also decreases the number of turns that will fit on a
the spool to a maximum OD of 1.5". This isn't working. I give up for
tonite.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

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