creating an electromagnet using my Amp / AC signal tia sal22

[Rick T]

Greetings All

I have a pt1100 amp with an impedance of 8 ohms rated at about (1000
watts output power) and a toroidal electromagnet with the resistance
of about 1 ohm. I'm doing an experiment with AC signals, audio and
toroidal coils. I'm trying to see how much I can increase the
magnetism inside the toroidal coil basically a donut electromagnet
using AC signals.

The steps I use:
I play a signal out my computer than it's amplified by the pt1100 amp
which is connected to the wire wound around a donut shape. Like this
http://www.codecogs.com/users/13108/img_em5.jpg

The problem I'm having is after I play the signal with about an 1 amp
running through the wire the internal circuit breaker in the pt1100
amp gets tripped. Is there a way I can get all the amps to flow
through the wire without tripping the internal circuit breaker of the
pt1100 amp?

Please not that the goal is to get as much current to flow though the
wires of the toroidal coil as possible to create an electromagnet
without tripping the internal circuit breaker of the amp. At the
moment I can't increase the windings. I tried putting a ceramic
100ohm 10 watt resistor in series with the coil to see if that would
help but the change was barley noticeable .

I also tried making a glass water resistor but it looks like most of
the current was dropped in the water doing electrolysis.

And also I can't use DC at this point.

PS: I'm using 18 gauge wire.

Tia sal22

[David Nebenzahl]

On 8/21/2009 6:45 PM Rick T spake thus:

> I have a pt1100 amp with an impedance of 8 ohms rated at about (1000
> watts output power) and a toroidal electromagnet with the resistance
> of about 1 ohm. I'm doing an experiment with AC signals, audio and
> toroidal coils. I'm trying to see how much I can increase the
> magnetism inside the toroidal coil basically a donut electromagnet
> using AC signals.
>
> The steps I use:
> I play a signal out my computer than it's amplified by the pt1100 amp
> which is connected to the wire wound around a donut shape. Like this
> http://www.codecogs.com/users/13108/img_em5.jpg
>
> The problem I'm having is after I play the signal with about an 1 amp
> running through the wire the internal circuit breaker in the pt1100
> amp gets tripped. Is there a way I can get all the amps to flow
> through the wire without tripping the internal circuit breaker of the
> pt1100 amp?

Nope.

The problem is pretty obvious, and I think you already know that you're
overloading the amp. Measure the resistance of your toroid coil: it's a
*lot* less than 1 ohm, right? You do the math, as they say.


--
Found--the gene that causes belief in genetic determinism

[Phil Allison[_3_]]

"Rick T"
>
> I have a pt1100 amp with an impedance of 8 ohms rated at about (1000
> watts output power)

** That is not any kind of 1000 watt amp.

It is PILE OF **** that retails for $89.


> and a toroidal electromagnet with the resistance
> of about 1 ohm. I'm doing an experiment with AC signals, audio and
> toroidal coils. I'm trying to see how much I can increase the
> magnetism inside the toroidal coil basically a donut electromagnet
> using AC signals.

** Insanity.


> The problem I'm having is after I play the signal with about an 1 amp
> running through the wire the internal circuit breaker in the pt1100
> amp gets tripped.

** Duuhhh !!

Amazing it has not yet blown up.


> Please not that the goal is to get as much current to flow though the
> wires of the toroidal coil as possible to create an electromagnet
> without tripping the internal circuit breaker of the amp.


** Insanity.

> And also I can't use DC at this point.


** Be of no help with toroid.




...... Phil

[isw]

In article
>,
Rick T > wrote:

> Greetings All
>
> I have a pt1100 amp with an impedance of 8 ohms rated at about (1000
> watts output power)

The amplifier you mentioned cannot deliver a "thousand-watt" output;
that's what it's capable of at the *peaks* of an audio signal, into
certain loads. It's probably less than half that continuous.

> and a toroidal electromagnet with the resistance
> of about 1 ohm.

For AC signals, what's important is not resistance, but impedance.

And that amp almost certainly cannot deliver anything like 300 to 400
watts into a one-ohm load. Audio amps are almost always limited in power
output by the amount of current they can deliver (so if whatever the
current is, can drive 400 watts into 8 ohms, it can only deliver 1/8 of
that power *at most* into one ohm, because the current will be the same.

> I'm doing an experiment with AC signals, audio and
> toroidal coils. I'm trying to see how much I can increase the
> magnetism inside the toroidal coil basically a donut electromagnet
> using AC signals.
>
> The steps I use:
> I play a signal out my computer than it's amplified by the pt1100 amp
> which is connected to the wire wound around a donut shape. Like this
> http://www.codecogs.com/users/13108/img_em5.jpg

Using a coil constructed according to that drawing, the magnetic flux
will be confined to the iron core. Did you expect to have a (powerful)
field in the "hole"? Because that won't happen. Toroids are preferred as
cores for coils and transformers *specifically because* they confine
magnetic fields better than other topologies.

What did you want/expect to happen here?

> The problem I'm having is after I play the signal with about an 1 amp
> running through the wire the internal circuit breaker in the pt1100
> amp gets tripped. Is there a way I can get all the amps to flow
> through the wire without tripping the internal circuit breaker of the
> pt1100 amp?

It's probable that you need either more turns or a higher frequency
(assuming the amp can handle that).

> Please not that the goal is to get as much current to flow though the
> wires of the toroidal coil as possible to create an electromagnet
> without tripping the internal circuit breaker of the amp.

The way to maximize current *using the amp you mentioned* is to get
enough wire on the toroid to make the load look like eight ohms (and
note that's *impedance*, not just resistance. And, you have to make sure
the wire you use has a large enough cross-section to handle that amount
of current (probably seven or eight amps *if everything works out*). The
next issue will be to make sure you don't saturate the toroid (ask it to
carry a larger magnetic field than it's capable of).

As I said, even if you get a lot of current to flow, there will be no
*external* magnetic field, possibly except for a bit of leakage.

> At the
> moment I can't increase the windings. I tried putting a ceramic
> 100ohm 10 watt resistor in series with the coil to see if that would
> help but the change was barley noticeable .

> I also tried making a glass water resistor but it looks like most of
> the current was dropped in the water doing electrolysis.

A series resistor may stop the breaker from tripping, but it will do
that by limiting the current, which is counterproductive if you want a
powerful field (the strength of which is proportional to the current
times the number of turns on your coil).

> And also I can't use DC at this point.

That would not produce an external field either.

> PS: I'm using 18 gauge wire.

The wire gauge is not first-order important here. It just gives you a
clue as to how much current might produce how much heating at some
specific frequency.

If you're genuinely interested in pursuing this project, I suggest you
do a bit of reading. Start with the relationships of resistqnce,
reactance, and impedance -- what they are, and how they are measured;
check into magnetic saturation and why it's a good idea to avoid it;
learn what the specs of that amplifier *really mean*, so you'll
understand just how much current it can actually deliver (at different
frequencies). Then you'll be much better equipped to get something
working that does what you want it to.

Isaac

[Trevor Wilson]

"Rick T" > wrote in message
...
> Greetings All
>
> I have a pt1100 amp with an impedance of 8 ohms rated at about (1000
> watts output power)

**BZZZZTT! Wrong. Given the abscence of real specs, I would guess that your
amp can deliver no more than 50 Watts/channel.

and a toroidal electromagnet with the resistance
> of about 1 ohm.

**Define "toroidal electromagnet". Electromagnets are NEVER toroidals. Are
you attempting to use a toroidal transformer as an electromagnet? You are
doomed to fail.

I'm doing an experiment with AC signals, audio and
> toroidal coils.

**Why? What frequency?

I'm trying to see how much I can increase the
> magnetism inside the toroidal coil basically a donut electromagnet
> using AC signals.

**Won't work with AC signals. Go read a text book on the subject.

>
> The steps I use:
> I play a signal out my computer than it's amplified by the pt1100 amp
> which is connected to the wire wound around a donut shape. Like this
> http://www.codecogs.com/users/13108/img_em5.jpg

**That is not an electromagnet. It is a simple inductor.

>
> The problem I'm having is after I play the signal with about an 1 amp
> running through the wire the internal circuit breaker in the pt1100
> amp gets tripped. Is there a way I can get all the amps to flow
> through the wire without tripping the internal circuit breaker of the
> pt1100 amp?

**You probably already are. Your pitifully crappy amplifier does not like
the abuse.

>
> Please not that the goal is to get as much current to flow though the
> wires of the toroidal coil as possible to create an electromagnet
> without tripping the internal circuit breaker of the amp. At the
> moment I can't increase the windings. I tried putting a ceramic
> 100ohm 10 watt resistor in series with the coil to see if that would
> help but the change was barley noticeable .
>
> I also tried making a glass water resistor but it looks like most of
> the current was dropped in the water doing electrolysis.
>
> And also I can't use DC at this point.

**Then stop wasting your time. Go study some texts on the subject.

>
> PS: I'm using 18 gauge wire.

**Doesn't matter what you are using. Whatever you're trying to do is doomed
to fail. Well, unless you want to destroy your POS amplifier. On that
aspect, you are on track to succeed.


--
Trevor Wilson
www.rageaudio.com.au

[GregS[_3_]]

In article >, Rick T > wrote:
>Greetings All
>
>I have a pt1100 amp with an impedance of 8 ohms rated at about (1000
>watts output power) and a toroidal electromagnet with the resistance
>of about 1 ohm. I'm doing an experiment with AC signals, audio and
>toroidal coils. I'm trying to see how much I can increase the
>magnetism inside the toroidal coil basically a donut electromagnet
>using AC signals.
>
>The steps I use:
>I play a signal out my computer than it's amplified by the pt1100 amp
>which is connected to the wire wound around a donut shape. Like this
>http://www.codecogs.com/users/13108/img_em5.jpg
>
>The problem I'm having is after I play the signal with about an 1 amp
>running through the wire the internal circuit breaker in the pt1100
>amp gets tripped. Is there a way I can get all the amps to flow
>through the wire without tripping the internal circuit breaker of the
>pt1100 amp?
>
>Please not that the goal is to get as much current to flow though the
>wires of the toroidal coil as possible to create an electromagnet
>without tripping the internal circuit breaker of the amp. At the
>moment I can't increase the windings. I tried putting a ceramic
>100ohm 10 watt resistor in series with the coil to see if that would
>help but the change was barley noticeable .
>
>I also tried making a glass water resistor but it looks like most of
>the current was dropped in the water doing electrolysis.
>
>And also I can't use DC at this point.
>
>PS: I'm using 18 gauge wire.
>
>Tia sal22


You need to use a variac.

[Trevor Wilson]

"GregS" > wrote in message
...
> In article
> >, Rick
> T > wrote:
>>Greetings All
>>
>>I have a pt1100 amp with an impedance of 8 ohms rated at about (1000
>>watts output power) and a toroidal electromagnet with the resistance
>>of about 1 ohm. I'm doing an experiment with AC signals, audio and
>>toroidal coils. I'm trying to see how much I can increase the
>>magnetism inside the toroidal coil basically a donut electromagnet
>>using AC signals.
>>
>>The steps I use:
>>I play a signal out my computer than it's amplified by the pt1100 amp
>>which is connected to the wire wound around a donut shape. Like this
>>http://www.codecogs.com/users/13108/img_em5.jpg
>>
>>The problem I'm having is after I play the signal with about an 1 amp
>>running through the wire the internal circuit breaker in the pt1100
>>amp gets tripped. Is there a way I can get all the amps to flow
>>through the wire without tripping the internal circuit breaker of the
>>pt1100 amp?
>>
>>Please not that the goal is to get as much current to flow though the
>>wires of the toroidal coil as possible to create an electromagnet
>>without tripping the internal circuit breaker of the amp. At the
>>moment I can't increase the windings. I tried putting a ceramic
>>100ohm 10 watt resistor in series with the coil to see if that would
>>help but the change was barley noticeable .
>>
>>I also tried making a glass water resistor but it looks like most of
>>the current was dropped in the water doing electrolysis.
>>
>>And also I can't use DC at this point.
>>
>>PS: I'm using 18 gauge wire.
>>
>>Tia sal22
>
>
> You need to use a variac.

**A risky move to suggest that a moron like this use a (non-isolated,
presumably) VariacT for such a doomed project. Still, maybe it's the best
thing for society as a whole....


--
Trevor Wilson
www.rageaudio.com.au

[Wim Lewis]

In article >,
Trevor Wilson > wrote:
>**Won't work with AC signals. Go read a text book on the subject.
[etc]


Huh. Are you related to Phil Allison?


--
Wim Lewis >, Seattle, WA, USA. PGP keyID 27F772C1
"We learn from history that we do not learn from history." -Hegel

[Trevor Wilson]

"Wim Lewis" > wrote in message
...
> In article >,
> Trevor Wilson > wrote:
>>**Won't work with AC signals. Go read a text book on the subject.
> [etc]
>
>
> Huh. Are you related to Phil Allison?

**No. Why do you ask? Did I use profanity in my post? Was I accurate and
succinct in my points?


--
Trevor Wilson
www.rageaudio.com.au

[Arny Krueger]

"Wim Lewis" > wrote in message

> In article >,
> Trevor Wilson > wrote:
>> **Won't work with AC signals. Go read a text book on the
>> subject. [etc]
>
>
> Huh. Are you related to Phil Allison?

No matter what, virtually every point that Trevor made in that post is true.