Hoist brake solenoid buzzes/fluckers instead of steadily pulling

[Ignoramus22978]

I have a 3 phase Yale 1/2 ton hoist. It has an electric brake with a
solenoid, whose job is to pull away the brake lever when 230VAC is
supplied to it.

The problem is that it does not do it. Instead of steadily pulling
away, it constantly jerks the lever, but never far enough to the end
point where it is supposed to be pulled away. So, the brake is not
disengaged as the hoist operates. I am glad that I noticed that.

I tried pulling on the lever by hand when the solenoid was engaged. I
noticed that if I help the solenoid and pull away the lever to the
end, jerking stops completely, but if I slowly let go of the lever and
it returns to the brake position, jerking resumes.

I am thinking that perhaps this solenoid has two separate coils,
pulling and holding one, and the holding one is not working or not
engaging?

Any idea?

thanks

[Tony Miklos]

It may have two windings on one coil. I deal with solenoids like that
all the time. The first strong winding pulls it in then opens a "end of
stroke" switch so it doesn't burn up. Then the second weaker winding is
just strong enough to hold it and can stay energized without burning up.
If the second weak winding is broke, you get a chattering action.

[Jamie]

Or it's actually a DC coil and there is suppose to be a diode in
series some where ?

If there isn't any large amount of debris from what you think is
a dragging brake pad, I would leave it alone. It could be a design
feature to simply release the pad to allow them to slip freely and not
create a gap between the disc. This would allow for the quickest
engagement of the pads when the hoist is deactivated and thus less
mechanical slip jerk.

I suppose it could be a AC coil with at shaded ring tip in the
core, if that is the case, there should be some sign of over heated
coil wire that would indicate a few shorted turns, if you can see them.

Also, do do make coils with embedded diodes.

Jamie

[Ignoramus22978]

Here's a picture.

http://boss-proxy.chudov.com/tmp/tmp-0432.jpg.html

i

[Michael A. Terrell]

Jamie wrote:
>
> Ignoramus22978 wrote:
>
> > I have a 3 phase Yale 1/2 ton hoist. It has an electric brake with a
> > solenoid, whose job is to pull away the brake lever when 230VAC is
> > supplied to it.
> >
> > The problem is that it does not do it. Instead of steadily pulling
> > away, it constantly jerks the lever, but never far enough to the end
> > point where it is supposed to be pulled away. So, the brake is not
> > disengaged as the hoist operates. I am glad that I noticed that.
> >
> > I tried pulling on the lever by hand when the solenoid was engaged. I
> > noticed that if I help the solenoid and pull away the lever to the
> > end, jerking stops completely, but if I slowly let go of the lever and
> > it returns to the brake position, jerking resumes.
> >
> > I am thinking that perhaps this solenoid has two separate coils,
> > pulling and holding one, and the holding one is not working or not
> > engaging?
> >
> > Any idea?
> >
> > thanks
>
> Or it's actually a DC coil and there is suppose to be a diode in
> series some where ?

Sigh. As usual, Maynard (AKA: jamie) misses the point. It takes more
than a diode in series to convert an AC solenoid into a DC solenoid.
You also need a filter capacitor or you are trying to operate it on a
half cycle of the AC waveform, giving you 230 * .707 or 162.61 volts
which is 50% of the power of a full cycle. With the filter capacitor
you get 230 * 1.414 or 325.22 DC


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

[BQ340]

On 11/13/2011 10:21 AM, Ignoramus22978 wrote:

>> I am thinking that perhaps this solenoid has two separate coils,
>> pulling and holding one, and the holding one is not working or not
>> engaging?
>>
>> Any idea?
>>
>> thanks

There would be more than 2 terminals on it if it had multiple windings.

MikeB

--
Email is valid but not checked often

[GeorgeD]

On 11/13/2011 10:21 AM, Ignoramus22978 wrote:

That solenoid requires that the pole pieces be in contact. Then it will
hold (strongly). If it can not close completely, it will vibrate. Not
much of a puller, but a big holder.

Check to make sure it can pull in fully and that the poles are not
cruded up. It looks like it only needs some cleaning and TLC.

There is only one coil. You get what you see.

[Jeffrey Angus]

On 11/13/2011 9:54 AM, GeorgeD wrote:
> That solenoid requires that the pole pieces be in contact. Then it will
> hold (strongly). If it can not close completely, it will vibrate. Not
> much of a puller, but a big holder.

Looks like your typical washing machine part. And yes, lots of hold
power when the pole pieces touch.

> Check to make sure it can pull in fully and that the poles are not
> cruded up. It looks like it only needs some cleaning and TLC.

Serious case of corrosion there. No telling how much surface crud
on the sliding parts.

> There is only one coil.

Of course, but we still have to listen to Maynard's view of multi-
windings and embedded diodes.

Jeff


--
"Everything from Crackers to Coffins"

[Jamie]

I didn't look at the picture before how ever, that solenoid needs replacing!

Between the corrosion, most likely in the wire too, the laminates
are most likely bad!

THat part of the equipment should be well closed to keep it much
cleaner than that!

P.S.

I know of an area of our work place where a whole bunch of new
solenoids are stored just for that hoist! We no longer have hoist
of that type in operation. The solenoids are kept on hand for R&D
material until they run out, they also make good look bolt retractors.


Jamie

[Jamie]

You don't need to listen to me at all, if facts bother you then just
please put me on your ignore list, I wouldn't want to be responsible for
causing you any pain and agony.

It's a shame the simple minded can't see past their nose.


Jamie

[hrho...@att.net]

On Nov 13, 8:00 am, Ignoramus22978 <ignoramus22...@NOSPAM.

Have you thought of contacting the manufactirer?

[Jeffrey Angus]

On 11/13/2011 10:18 AM, Jamie wrote:
> It's a shame the simple minded can't see past their nose.

How ironic.

[Jamie]

Jeffrey Angus wrote:

> On 11/13/2011 10:18 AM, Jamie wrote:
>
>> It's a shame the simple minded can't see past their nose.
>
>
> How ironic.
>
> Jeff
>

Yeah, isn't it?

Hope you enjoy your dilemma..

Have a nice day.

Jamie

[Tony Miklos]

On 11/13/2011 10:21 AM, Ignoramus22978 wrote:

> Here's a picture.
>
> http://boss-proxy.chudov.com/tmp/tmp-0432.jpg.html

I don't see the wires. How many wires does the solenoid have?

[Jeff Liebermann]

On Sun, 13 Nov 2011 09:21:30 -0600, Ignoramus22978
<ignoram...@NOSPAM.22978.invalid> wrote:

>Here's a picture.
>http://boss-proxy.chudov.com/tmp/tmp-0432.jpg.html

Clean off the corrosion before blundering forward. It's likely that
the jerkiness is cuased by corrosion or rust on the moving parts of
the solenoid. I suggest you tear it apart, clean off what can be
easily removed, use a wire brush on everything else, coat is with some
kind of sealer (clear acrylic), and make sure everything moves easily
and correctly before reassembling. If that's too much, it looks like
the solenoid can be removed with 4 screws and a cotter pin, so start
cleaning there.
--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

[Lloyd E. Sponenburgh]

"Michael A. Terrell" <mike.t...@earthlink.net> fired this volley in
news:2-qdnbSWuLmrfyLT...@earthlink.com:

> Sigh. As usual, Maynard (AKA: jamie) misses the point. It takes
more
> than a diode in series to convert an AC solenoid into a DC solenoid.
> You also need a filter capacitor or you are trying to operate it on a
> half cycle of the AC waveform, giving you 230 * .707 or 162.61 volts
> which is 50% of the power of a full cycle. With the filter capacitor
> you get 230 * 1.414 or 325.22 DC

Michael, it's even less than that: Full-wave single-phase rectified AC
has an area under the curve of .707*Vpeak. Half-wave has half THAT area.
If you filter half-wave, and draw no current from the cap, it charges to
peak V-in.

Filtered - either half-wave or full-wave - the DC voltage never rises
above peak, regardless of draw, unless you use a doubler circuit. A
full-wave rectifier (with or without filtering) is not a doubler.

Lloyd

[Michael A. Terrell]

How is 230 * 1.414 a doubler? It is a simple rectifier & filter for
the input voltage. Of course you have the forward drop of the
rectifier, and it will be less than that if the filter is too small.
You don't need a full wave bridge, or millions of old line operated
radios would have never worked. They were a simple rectifier & a 160
VDC electrolytic, usually around 30 湩.

[Ignoramus22978]

On 2011-11-13, BQ340 <bq...@Adelphia.net> wrote:
> On 11/13/2011 10:21 AM, Ignoramus22978 wrote:
>
>>> I am thinking that perhaps this solenoid has two separate coils,
>>> pulling and holding one, and the holding one is not working or not
>>> engaging?
>>>
>>> Any idea?
>>>
>>> thanks
>
> There would be more than 2 terminals on it if it had multiple windings.
>
> MikeB
>

OK, I kind of suspected that also (based on my past diesel generator
experiences).

i

[Michael A. Terrell]

What else do you expect from 'Skippy - V2.0'? He also thinks
Electret microphones are crystal microphones, and that you can easily
change the bandgap in LEDs to adjust the color. He's a real, no class
clown on sci.electronics.design.

[Ignoramus22978]

I put some penetrating oil on the screws, I will get it off and clean
thoroughly. Thanks.

i

[Ignoramus22978]

Two.

i

[Lloyd E. Sponenburgh]

"Michael A. Terrell" <mike.t...@earthlink.net> fired this volley in

news:2-SdnfxviMFXnF3T...@earthlink.com:

> How is 230 * 1.414 a doubler? It is a simple rectifier & filter for
> the input voltage. Of course you have the forward drop of the
> rectifier, and it will be less than that if the filter is too small.
>

You are missing a basic point. 230VAC line voltage is measured RMS (root-
mean-square) it's peak is 230*sqrt(2). I said, "the voltage will never
rise above peak".

<G>
Lloyd

[Lloyd E. Sponenburgh]

Ignoramus22978 <ignoram...@NOSPAM.22978.invalid> fired this volley in
news:TcednaUF1axtn13T...@giganews.com:

> Two.

Ig, there is a case where a diode might be used, but you'd see it, and a
switch to cut it in and out of circuit, if it were there.

The case is where a coil is wound "strong" for pull-in, then a diode is
placed in series to lower the coil's average current during the hold phase.

However, that would be obvious, and external to the coil.

LLoyd

[Tony Miklos]

I've also worked on solenoids like that that have a switch and a
resistor for the "hold" circuit. Follow the wires. Same thing, if the
resistor or that circuit is open the solenoid will chatter open and closed.

This is assuming the solenoid does chatter, as if it's being turned on
and off rapidly, like a machine gun.

If it's just hanging up part way and buzzing then I'd agree with the
people who said to clean it up or replace it.

[Jamie]

It's nice that you are attempting to help others, very admiral of you
how ever, this person you are replying to has been on my ignore list for
some time now and for good reason. You may also learn why if you haven't
already.

I also write software at times and posted a question about options
that may exist in the "NNTP" protocol, which is used here, to exclude
down loading from the server if I happen to have a exclusion of a user
in the
header of the post. It gets messy trying to ignore these characters even
though you have your own reader configured to do so, how ever, reading
others post ends up showing you users that you don't want any thing to
do with.

I just though it would save lots of bandwidth for others to use and
enjoy.

I guess it's just a weakness in the protocol.

Jamie

[Lloyd E. Sponenburgh]

Jamie <jamie_ka1lpa_not_v...@charter.net> fired this
volley in news:WVTvq.35422$yY3....@newsfe01.iad:

> I just though it would save lots of bandwidth for others to use and
> enjoy.

Jamie, he was correct, except for forgetting that AC line voltage is the
root mean square of it's peak. A lot of people forget that.

I'm an old radio guy from the 60's, too. That was long before the advent
of switching power supplies. To get 5VDC at 1A off the mains used to
take a 1lb transformer, and about 40 cu.in. of rectifiers and filters --
and regulation sucked unless you really over-sized the transformer.

Now you can get that out of a 1/2-oz wall wart!

LLoyd

[Jamie]

The point is that he goes out of his way making an idiot of himself, he
can't even get my identity correct. I am not the only user with this name.

I deal with this crap at work all the time when the electricians walk
over to me with unexplained problems, some of which are hoist how ever,
we deal with much larger cranes than what is being talked about here.

We just recently had a 10 ton crane inspected after a repair done on
the motor brake which is much different than what is being talked about
here. That one uses a DC coil with a bridge rectifier and this bridge is
actually encased in the coil pack. This coil can operate from AC or DC
how ever, the way this one is being operated is it first gets energized
via 48V AC, then a time delay relay opens its contacts to operate a
single diode inline which allows for 50% duty to the coil for holding..
It is a Peak and hold motor brake and works very well. We had to
replace it not to long ago because the contacts in the control box got
welded and what happens is with a lot of constant use the coil heats up
the spline and starts to stick and thus does not always close
afterwards. You can picture what happens to the load when the operator
releases the buttons.

Personally I stay clear of MT. He is a force to be reckon with. Also I
never made any comment on his evaluation of the math or what ever he
spit out, I just don't bother reading his crap because it normally has
nothing to do with helping any one. I only see him from other users
posting replies.


Jamie

[Gunner Asch]

On Sun, 13 Nov 2011 08:00:33 -0600, Ignoramus22978

<ignoram...@NOSPAM.22978.invalid> wrote:

>I have a 3 phase Yale 1/2 ton hoist. It has an electric brake with a
>solenoid, whose job is to pull away the brake lever when 230VAC is
>supplied to it.
>
>The problem is that it does not do it. Instead of steadily pulling
>away, it constantly jerks the lever, but never far enough to the end
>point where it is supposed to be pulled away. So, the brake is not
>disengaged as the hoist operates. I am glad that I noticed that.
>
>I tried pulling on the lever by hand when the solenoid was engaged. I
>noticed that if I help the solenoid and pull away the lever to the
>end, jerking stops completely, but if I slowly let go of the lever and
>it returns to the brake position, jerking resumes.
>
>I am thinking that perhaps this solenoid has two separate coils,
>pulling and holding one, and the holding one is not working or not
>engaging?
>
>Any idea?
>
>thanks

Check to see if its not wired up for 440/480

Most of those hoists are dual voltage and while they will run on 220 if
wired for 440..the solenoids most often will not


One could not be a successful Leftwinger without realizing that,
in contrast to the popular conception supported by newspapers
and mothers of Leftwingers, a goodly number of Leftwingers are
not only narrow-minded and dull, but also just stupid.
Gunner Asch

[Michael A. Terrell]

Jamie wrote:
>
> The point is that he goes out of his way making an idiot of himself, he
> can't even get my identity correct. I am not the only user with this name.

Maynard A Philbrook JR is the only one with the callsign KA1LPA.

http://call-signs.findthebest.com/l/63823/KA1LPA

[Ignoramus22978]

On 2011-11-13, Tony Miklos <Tony....@gmail.com> wrote:
> On 11/13/2011 12:48 PM, Ignoramus22978 wrote:
>> On 2011-11-13, Tony Miklos<Tony....@gmail.com> wrote:
>>> On 11/13/2011 10:21 AM, Ignoramus22978 wrote:
>>>> Here's a picture.
>>>>
>>>> http://boss-proxy.chudov.com/tmp/tmp-0432.jpg.html
>>>
>>> I don't see the wires. How many wires does the solenoid have?
>>
>> Two.
>
> I've also worked on solenoids like that that have a switch and a
> resistor for the "hold" circuit. Follow the wires. Same thing, if the
> resistor or that circuit is open the solenoid will chatter open and closed.
>
> This is assuming the solenoid does chatter, as if it's being turned on
> and off rapidly, like a machine gun.

This is exactly what it does.

> If it's just hanging up part way and buzzing then I'd agree with the
> people who said to clean it up or replace it.

No, it chatters like a machine gun.

i

[Ignoramus22978]

On 2011-11-13, Gunner Asch <gunne...@gmail.com> wrote:
> On Sun, 13 Nov 2011 08:00:33 -0600, Ignoramus22978
><ignoram...@NOSPAM.22978.invalid> wrote:
>
>>I have a 3 phase Yale 1/2 ton hoist. It has an electric brake with a
>>solenoid, whose job is to pull away the brake lever when 230VAC is
>>supplied to it.
>>
>>The problem is that it does not do it. Instead of steadily pulling
>>away, it constantly jerks the lever, but never far enough to the end
>>point where it is supposed to be pulled away. So, the brake is not
>>disengaged as the hoist operates. I am glad that I noticed that.
>>
>>I tried pulling on the lever by hand when the solenoid was engaged. I
>>noticed that if I help the solenoid and pull away the lever to the
>>end, jerking stops completely, but if I slowly let go of the lever and
>>it returns to the brake position, jerking resumes.
>>
>>I am thinking that perhaps this solenoid has two separate coils,
>>pulling and holding one, and the holding one is not working or not
>>engaging?
>>
>>Any idea?
>>
>>thanks
>
> Check to see if its not wired up for 440/480
>
> Most of those hoists are dual voltage and while they will run on 220 if
> wired for 440..the solenoids most often will not

The hoist can be entirely rewired for 240/480. It actually WAS wired
for 480 and I had to rewire. So, you are saying that to complete this
transition to 240, I would have to replace the solenoid?

i

[Jeffrey Angus]

On 11/13/2011 8:52 PM, Ignoramus22978 wrote:
> The hoist can be entirely rewired for 240/480. It actually WAS wired
> for 480 and I had to rewire. So, you are saying that to complete this
> transition to 240, I would have to replace the solenoid?
>
> i

Ok, let's back up a bit. WHEN was the last time the hoist worked
like it should? When it was installed and operating on 480 v?

Or was it working at some point when re-wired for 240 v and THEN
started to act up with the brake solenoid?

[Bruce L. Bergman (munged human readable)]

On Sun, 13 Nov 2011 09:28:30 -0500, Tony Miklos
<Tony....@gmail.com> wrote:

>On 11/13/2011 9:00 AM, Ignoramus22978 wrote:
>> I have a 3 phase Yale 1/2 ton hoist. It has an electric brake with a
>> solenoid, whose job is to pull away the brake lever when 230VAC is
>> supplied to it.
>>
>> The problem is that it does not do it. Instead of steadily pulling
>> away, it constantly jerks the lever, but never far enough to the end
>> point where it is supposed to be pulled away. So, the brake is not
>> disengaged as the hoist operates. I am glad that I noticed that.
>>
>> I tried pulling on the lever by hand when the solenoid was engaged. I
>> noticed that if I help the solenoid and pull away the lever to the
>> end, jerking stops completely, but if I slowly let go of the lever and
>> it returns to the brake position, jerking resumes.
>>
>> I am thinking that perhaps this solenoid has two separate coils,
>> pulling and holding one, and the holding one is not working or not
>> engaging?
>>
>> Any idea?
>>
>> thanks
>

>It may have two windings on one coil. I deal with solenoids like that
>all the time. The first strong winding pulls it in then opens a "end of
>stroke" switch so it doesn't burn up. Then the second weaker winding is
>just strong enough to hold it and can stay energized without burning up.
> If the second weak winding is broke, you get a chattering action.

That would be a "Pick and Hold" solenoid. The "Pick" is the strong
winding with the switch, and the Hold would be the weak constant
winding.

And the Pick might not be able to pick without the Hold being
energized too, so it buzzes and doesn't open all the way. Or it's
bouncing on the end switch - hard to tell without looking.

Check the connections - If it's two separate windings, there might be
a loose lead.

--<< Bruce >>--

[Bruce L. Bergman (munged human readable)]

Yup, it's just a standard box solenoid, probably Dormeyer they make
zillions of them - and all crapped up inside that end-bell. If it was
something fancy it would look it.

Take it apart and clean up all the sliding and metal surfaces, a
little dab of Lubriplate white grease on the moving pole pieces inside
the solenoid, and hit it with some clear-coat to stop the surface rust
on the metal parts - and stop leaving it outside in the rain.

You do NOT want to pull an "Honest Al Babin" and start painting all
over the insides. You want to see if something is starting to crack.

--<< Bruce >>--

[Gunner Asch]

No..it means you didnt get everything changed over to 240. Check your
diagrams again. Something is still trying to run at 480 and its not
working..hence the solenoid chattering

Gunner

[Ignoramus22978]

I bought it at auction.

I have never seen this hoist run.

At my place, I have 240v 3ph only. (well, I have a transformer that I
could wire to get 460v, but it is sitting in the corner right now).

i

[Ignoramus22978]

Well, what I know is that I did measure voltage at the solenoid
terminals, and it was 230v.

i

[Gunner Asch]

On Mon, 14 Nov 2011 02:40:30 -0600, Ignoramus22978

Recheck all your wiring. And then see if the solenoids have any markings
on them that may indicate they were replaced with 480 only ones.

That chattering would indicate they are not getting enough poop to hold.

Got a 480 transformer? Rewire back to 480 and see if it works properly
at that voltage.

If there is 230 on those terminals..it means something is not properly
if the solenoids are the stock ones. So they may not be the stock ones.

[Gunner Asch]

Time to hook it up and set it up as a 480 power supply WITH DIFFERNT
PLUGS than your 240 system. You will run a lot of 480 stuff through
your shop..and you will need a power source to run/demo/test that
stuff.

Gunner

[Tony Miklos]

Follow the solenoid wires to look for an end of stroke switch. If it
has one it will be actuated and open when the solenoid is pulled in.
Check that circuit for a resistor or something else to lower the
solenoid voltage. The problem is that it gets power on the pull stroke
but no power for the hold position.

[Jeffrey Angus]

On 11/13/2011 9:21 AM, Ignoramus22978 wrote:
> Here's a picture.
>
> http://boss-proxy.chudov.com/tmp/tmp-0432.jpg.html

That amount of surface rust and corrosion INSIDE a cover
indicates it's been wet, or in a wet location.

That's a disc brake and should dis-engage when the hoist
is in operation.

Do you have the wiring diagram for this hoist?

I know that label reads, "Caution dual voltage" as an
indication it "might be wired for a different voltage than
what you're using.

Despite all the random guessing, I'm assuming that is a
very simple straight forward coil that pulls the release
on the disc brake.

If that coil is set up for 480 volts and you're putting 240
across it, it IS going to buzz and chatter. It will do that
without any missing diodes, open coils, hidden switches or
two sets pull & hold windings.

If that coil is set up for "dual voltage" it should have
more that two wires connecting to it. Or there should be a
control transformer somewhere else in the housing to supply
the correct voltage to a single voltage coil. Or a dropping
resistor (not likely) to allow a 240 coil to be used on 480.
And the instructions, as such, should have the connection
for both voltages and everything you have to reconnect listed.

[Gunner Asch]

On Mon, 14 Nov 2011 09:59:40 -0600, Jeffrey Angus <grend...@aim.com>
wrote:

The several I own (CMS) have internal transformers that allow voltage
changes. to the workings.

Though he does say that he has 240 on the coils..which is troublesome

[Jamie]

If that being the case, I then would assume that maybe the solenoid was
getting its voltage from one of the star windings on the motor?

A connection from wire 4 to wire 5 should provide ~ 230V Ac when the
motor is wired for 480 which is a standard way of doing it, how ever, I
wonder if you considered this when you did your change over?

Of course, I don't know anything about anything so don't listen to me.

Jamie

[Jamie]

Ok, so what is the original coil voltage suppose to be? 230 or 480?

You do know that many of those types of devices that allow you to
rewire uses the same coil for both voltages? Normally the coil is
spec'd out for 230V AC.. which will work in either case, it's just
where you connect the wires to.

Jamie

[hrho...@att.net]

On Nov 14, 7:35 pm, Jamie
<jamie_ka1lpa_not_valid_after_ka1l...@charter.net> wrote:
> Ignoramus22978 wrote:

>   Jamie- Hide quoted text -
>
> - Show quoted text -

Has the OP ever said if there are two or three or how many wires going
to the solenoid????

[Jamie]

From what I can remember, it's a simple 2 wire solenoid.. That being the
case, they should be connected to the # 1 & 2 wires of the motor relay
output side M1,M2. If it was wired for 480, then the coil is connected
to the #4 and #5 for example. That will get half the voltage when the
motor operates. Standard for AC motors with add on brake on the back..

Jamie

[Cydrome Leader]

In sci.electronics.repair Michael A. Terrell <mike.t...@earthlink.net> wrote:
>
> Jeffrey Angus wrote:
>>
>> On 11/13/2011 9:54 AM, GeorgeD wrote:
>> > That solenoid requires that the pole pieces be in contact. Then it will
>> > hold (strongly). If it can not close completely, it will vibrate. Not
>> > much of a puller, but a big holder.
>>
>> Looks like your typical washing machine part. And yes, lots of hold
>> power when the pole pieces touch.
>>
>> > Check to make sure it can pull in fully and that the poles are not
>> > cruded up. It looks like it only needs some cleaning and TLC.
>>
>> Serious case of corrosion there. No telling how much surface crud
>> on the sliding parts.
>>
>> > There is only one coil.
>>
>> Of course, but we still have to listen to Maynard's view of multi-
>> windings and embedded diodes.
>
>
> What else do you expect from 'Skippy - V2.0'? He also thinks
> Electret microphones are crystal microphones, and that you can easily
> change the bandgap in LEDs to adjust the color. He's a real, no class

Not sure about the flamewar going on here, but it's actually not hard to
get a LED to change colors. Get some liquid nitrogen and try it out.