Cylindrical. Axial leads.

Ordered caps for a speaker crossover because the leads had literally been shaken out of the originals. But I had no luck finding those bulbs. I would rather not jump it out. I guess I could and just put a beefier horn in it.

On 24/10/2015 15:07, wrote:
Cylindrical. Axial leads.

Ordered caps for a speaker crossover because the leads had literally been shaken out of the originals. But I had no luck finding those bulbs. I would rather not jump it out. I guess I could and just put a beefier horn in it.


Possibly an automotive parts store, depending on what voltage rating was
originally fitted. Some trailer lights use them. If it was not 12V or
24V then you'd have to look elsewhere.

wrote:
Cylindrical. Axial leads.

Ordered caps for a speaker crossover because the leads had literally been
shaken out of the originals. But I had no luck finding those bulbs. I
would rather not jump it out. I guess I could and just put a beefier horn in it.

I assume they are burnt out. You could try a 12 volt lamp with no more than
1-2 ohms cold resistance. You could also use a tweeter protector PTC
resistor.
I assume they were overdriven.

Greg

wrote in message
...

Cylindrical. Axial leads.

Ordered caps for a speaker crossover because the leads had literally been
shaken out of the originals. But I had no luck finding those bulbs. I would
rather not jump it out. I guess I could and just put a beefier horn in it.





http://www.parts-express.com/speaker...-lamp--260-231

http://www.amazon.com/Eminence-PX-Re.../dp/B000BBOVS0



Gareth.

wrote in message
...

Cylindrical. Axial leads.

Ordered caps for a speaker crossover because the leads had literally been
shaken out of the originals. But I had no luck finding those bulbs. I would
rather not jump it out. I guess I could and just put a beefier horn in it.





JBL also do one with flying leads.

https://www.bluearan.co.uk/index.php?id=JBLSK3BULB



Gareth.

On Friday, October 23, 2015 at 9:07:18 PM UTC-7, wrote:
Cylindrical. Axial leads.

Ordered caps for a speaker crossover because the leads had literally been shaken out of the originals. But I had no luck finding those bulbs. I would rather not jump it out. I guess I could and just put a beefier horn in it.

It's called a "barreter". It's just a lamp used as a current limiter.

On 24/10/2015 3:07 PM, wrote:
Cylindrical. Axial leads.

Ordered caps for a speaker crossover because the leads had literally
been shaken out of the originals. But I had no luck finding those
bulbs. I would rather not jump it out. I guess I could and just put a
beefier horn in it.


**Select an appropriate sized Polyswitch™. Cheap, reliable and effective.

--
Trevor Wilson
www.rageaudio.com.au

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

"Trevor Wilson" wrote in message ...

On 24/10/2015 3:07 PM, wrote:
Cylindrical. Axial leads.

Ordered caps for a speaker crossover because the leads had literally
been shaken out of the originals. But I had no luck finding those
bulbs. I would rather not jump it out. I guess I could and just put a
beefier horn in it.


**Select an appropriate sized Polyswitch™. Cheap, reliable and effective.





Polyswitches are not compressors.



Gareth.

On 25/10/2015 8:49 AM, Gareth Magennis wrote:


"Trevor Wilson" wrote in message ...

On 24/10/2015 3:07 PM, wrote:
Cylindrical. Axial leads.

Ordered caps for a speaker crossover because the leads had literally
been shaken out of the originals. But I had no luck finding those
bulbs. I would rather not jump it out. I guess I could and just put a
beefier horn in it.


**Select an appropriate sized Polyswitch™. Cheap, reliable and effective.





Polyswitches are not compressors.


**Correct. They're much better. They protect drivers, without
significant audible problems (like compression).


--
Trevor Wilson
www.rageaudio.com.au

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

"Trevor Wilson" wrote in message ...

On 25/10/2015 8:49 AM, Gareth Magennis wrote:


"Trevor Wilson" wrote in message ...

On 24/10/2015 3:07 PM, wrote:
Cylindrical. Axial leads.

Ordered caps for a speaker crossover because the leads had literally
been shaken out of the originals. But I had no luck finding those
bulbs. I would rather not jump it out. I guess I could and just put a
beefier horn in it.


**Select an appropriate sized Polyswitch™. Cheap, reliable and effective.





Polyswitches are not compressors.


**Correct. They're much better. They protect drivers, without
significant audible problems (like compression).






Do you think you would be able to hear such a compression problem?


Gareth.

On 25/10/2015 11:54 AM, Gareth Magennis wrote:


"Trevor Wilson" wrote in message ...

On 25/10/2015 8:49 AM, Gareth Magennis wrote:


"Trevor Wilson" wrote in message
...

On 24/10/2015 3:07 PM, wrote:
Cylindrical. Axial leads.

Ordered caps for a speaker crossover because the leads had literally
been shaken out of the originals. But I had no luck finding those
bulbs. I would rather not jump it out. I guess I could and just put a
beefier horn in it.


**Select an appropriate sized Polyswitch™. Cheap, reliable and effective.





Polyswitches are not compressors.


**Correct. They're much better. They protect drivers, without
significant audible problems (like compression).






Do you think you would be able to hear such a compression problem?

**Absolutely. I've proven it, under blind test conditions, to clients
who own speakers that are equipped with such things.


--
Trevor Wilson
www.rageaudio.com.au

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

Trevor Wilson wrote:


**Select an appropriate sized Polyswitch(tm). Cheap, reliable and effective.


** Polyswitches are not a good alternative to low voltage lamps with horn drivers in systems used for sound reinforcement.

Biggest problem is the sudden switch off of the horn and long wait for it to come back on - this is unacceptable to performers or audiences.

OTOH, correctly chosen lamps act immediately - reducing the over power condition to a safe level for the horn driver and then recover almost as fast.

Many active systems use limiters that do the same job.


.... Phil

"Trevor Wilson" wrote in message ...

On 25/10/2015 11:54 AM, Gareth Magennis wrote:


"Trevor Wilson" wrote in message ...

On 25/10/2015 8:49 AM, Gareth Magennis wrote:


"Trevor Wilson" wrote in message
...

On 24/10/2015 3:07 PM, wrote:
Cylindrical. Axial leads.

Ordered caps for a speaker crossover because the leads had literally
been shaken out of the originals. But I had no luck finding those
bulbs. I would rather not jump it out. I guess I could and just put a
beefier horn in it.


**Select an appropriate sized Polyswitch™. Cheap, reliable and effective.





Polyswitches are not compressors.


**Correct. They're much better. They protect drivers, without
significant audible problems (like compression).






Do you think you would be able to hear such a compression problem?

**Absolutely. I've proven it, under blind test conditions, to clients
who own speakers that are equipped with such things.




OK, but the point I didn't quite make yesterday was that you would only hear
such a compression "problem" if the system was being abused, i.e.
overdriven.
This is when the compression kicks in, to protect the tweeter.

To single out the compression as a problem is to completely ignore the
simple fact that this is happening because of a far bigger problem
elsewhere, and the volume needs to be reduced before something blows up.


Gareth.

"Ken Layton" wrote in message
...
On Friday, October 23, 2015 at 9:07:18 PM UTC-7, wrote:
Cylindrical. Axial leads.

Ordered caps for a speaker crossover because the leads had literally been
shaken out of the originals. But I had no luck finding those bulbs. I
would rather not jump it out. I guess I could and just put a beefier horn
in it.

It's called a "barreter". It's just a lamp used as a current limiter.

The earliest reference I could find to baretter was from the pioneering days
of wireless - apparently it was used as a detector.

The type I remember from the days of AC/DC TVs and radios was an iron wire
filament enclosed in a hydrogen filled envelope.

The series chain of heaters had a very low cold resistance, so the baretter
was included in series with any dropper resistor to reduce the surge current
when switching on from cold.

In later equipment, NTC themistors became the norm, they reduce in
resistance as current through them causes them to heat up, so they
compensate for the low cold resistance of heaters.

The Polyfuse is a PTC thermistor; the resistance increases with temperature,
at room temperature the resistance should be insignificant in the
application, too much current causes heating and the Polyfuse has a sharp
knee, so it cuts off current to the load till it cools again.

The thermistor types have significant recovery time - the PTC thermistor
used to deliver a decaying burst of AC to the degauss coil in a CRT display
had about 6 minute recovery time.

On 26/10/2015 6:32 AM, Gareth Magennis wrote:


"Trevor Wilson" wrote in message ...

On 25/10/2015 11:54 AM, Gareth Magennis wrote:


"Trevor Wilson" wrote in message
...

On 25/10/2015 8:49 AM, Gareth Magennis wrote:


"Trevor Wilson" wrote in message
...

On 24/10/2015 3:07 PM, wrote:
Cylindrical. Axial leads.

Ordered caps for a speaker crossover because the leads had literally
been shaken out of the originals. But I had no luck finding those
bulbs. I would rather not jump it out. I guess I could and just put a
beefier horn in it.


**Select an appropriate sized Polyswitch™. Cheap, reliable and
effective.





Polyswitches are not compressors.


**Correct. They're much better. They protect drivers, without
significant audible problems (like compression).






Do you think you would be able to hear such a compression problem?

**Absolutely. I've proven it, under blind test conditions, to clients
who own speakers that are equipped with such things.




OK, but the point I didn't quite make yesterday was that you would only
hear such a compression "problem" if the system was being abused, i.e.
overdriven.
This is when the compression kicks in, to protect the tweeter.

**Well, yes it does. However, it depends on the system. For sound
reinforcement, the compression effects are not likely to be a problem,
though most professional systems use far more sophisticated electronic
compression systems.


To single out the compression as a problem is to completely ignore the
simple fact that this is happening because of a far bigger problem
elsewhere, and the volume needs to be reduced before something blows up.

**In domestic systems a Polyswitch™ is, IMO, a better choice.

I located and measured a long, thin filament lamp (which looks like a
baretter). Part # GE1936. Nominally, I would guess it is a 12 Volt lamp.
At 12 Volts, current consumption is 0.75 Amps. Here is the resistance
plot, vs. current:

0.1 A - 1.7 Ohms
0.2 A - 2.15 Ohms
0.3 A - 3.4 Ohms
0.4 A - 6.3 Ohms
0.5 A - 9.68 Ohms
0.6 A - 12.53 Ohms
0.7 A - 15.13 Ohms
0.75 A - 16 Ohms

A Polyswitch™ typically exhibits insignificant resistance changes, until
the switching point is reached. They're self-resetting and, provided
Voltage ratings are not exceeded, quite reliable.

--
Trevor Wilson
www.rageaudio.com.au

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

On Saturday, October 24, 2015 at 12:07:18 AM UTC-4, wrote:
Cylindrical. Axial leads.

Ordered caps for a speaker crossover because the leads had literally been shaken out of the originals. But I had no luck finding those bulbs. I would rather not jump it out. I guess I could and just put a beefier horn in it.

How big are they? We buy little incandescent bulbs from Mouser.
http://www.mouser.com/ds/2/423/T-11_...nal-552494.pdf

They might have others.. not the best search engine.

George H.

On Sunday, October 25, 2015 at 7:12:18 PM UTC-4, Trevor Wilson wrote:
On 26/10/2015 6:32 AM, Gareth Magennis wrote:


"Trevor Wilson" wrote in message ...

On 25/10/2015 11:54 AM, Gareth Magennis wrote:


"Trevor Wilson" wrote in message
...

On 25/10/2015 8:49 AM, Gareth Magennis wrote:


"Trevor Wilson" wrote in message
...

On 24/10/2015 3:07 PM, wrote:
Cylindrical. Axial leads.

Ordered caps for a speaker crossover because the leads had literally
been shaken out of the originals. But I had no luck finding those
bulbs. I would rather not jump it out. I guess I could and just put a
beefier horn in it.


**Select an appropriate sized Polyswitch(tm). Cheap, reliable and
effective.





Polyswitches are not compressors.


**Correct. They're much better. They protect drivers, without
significant audible problems (like compression).






Do you think you would be able to hear such a compression problem?

**Absolutely. I've proven it, under blind test conditions, to clients
who own speakers that are equipped with such things.




OK, but the point I didn't quite make yesterday was that you would only
hear such a compression "problem" if the system was being abused, i.e.
overdriven.
This is when the compression kicks in, to protect the tweeter.

**Well, yes it does. However, it depends on the system. For sound
reinforcement, the compression effects are not likely to be a problem,
though most professional systems use far more sophisticated electronic
compression systems.


To single out the compression as a problem is to completely ignore the
simple fact that this is happening because of a far bigger problem
elsewhere, and the volume needs to be reduced before something blows up.

**In domestic systems a Polyswitch(tm) is, IMO, a better choice.

I located and measured a long, thin filament lamp (which looks like a
baretter). Part # GE1936. Nominally, I would guess it is a 12 Volt lamp.
At 12 Volts, current consumption is 0.75 Amps. Here is the resistance
plot, vs. current:

0.1 A - 1.7 Ohms
0.2 A - 2.15 Ohms
0.3 A - 3.4 Ohms
0.4 A - 6.3 Ohms
0.5 A - 9.68 Ohms
0.6 A - 12.53 Ohms
0.7 A - 15.13 Ohms
0.75 A - 16 Ohms

A Polyswitch(tm) typically exhibits insignificant resistance changes, until
the switching point is reached. They're self-resetting and, provided
Voltage ratings are not exceeded, quite reliable.

--
Trevor Wilson
www.rageaudio.com.au

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

Hi Trevor, I'm not an audio guy. But one thing about polyswitches is that
they do age.. the more times they trip the lower the trip point.
I don't know if that would be an issue where you use them.

George H.

Ian Field wrote:


"Ken Layton" wrote in message
...
On Friday, October 23, 2015 at 9:07:18 PM UTC-7, wrote:
Cylindrical. Axial leads.

Ordered caps for a speaker crossover because the leads had literally been
shaken out of the originals. But I had no luck finding those bulbs. I
would rather not jump it out. I guess I could and just put a beefier horn
in it.

It's called a "barreter". It's just a lamp used as a current limiter.

The earliest reference I could find to baretter was from the pioneering days
of wireless - apparently it was used as a detector.

The type I remember from the days of AC/DC TVs and radios was an iron wire
filament enclosed in a hydrogen filled envelope.

What did these tubes look like, any idea why they used iron and hydrogen?

"Cydrome Leader" wrote in message
...
Ian Field wrote:


"Ken Layton" wrote in message
...
On Friday, October 23, 2015 at 9:07:18 PM UTC-7,
wrote:
Cylindrical. Axial leads.

Ordered caps for a speaker crossover because the leads had literally
been
shaken out of the originals. But I had no luck finding those bulbs. I
would rather not jump it out. I guess I could and just put a beefier
horn
in it.

It's called a "barreter". It's just a lamp used as a current limiter.

The earliest reference I could find to baretter was from the pioneering
days
of wireless - apparently it was used as a detector.

The type I remember from the days of AC/DC TVs and radios was an iron
wire
filament enclosed in a hydrogen filled envelope.

What did these tubes look like, any idea why they used iron and hydrogen?

They were long-ish tubes with an octal base. There was a glass stem inside
with radial support spring struts and the wire zig-zagged up and down to
complete a circle inside the tube.

When I got into the trade, they'd been largely superseded by rod type
thermistors, there was just the odd one or two turned up in older gear - as
they never gave me any problem, I never bothered researching it much.

Searching; "C1.pdf" will get you a datasheet, or search; "barretter" will
get you some old radio museum pages for stuff they're used in.

On 27/10/2015 3:58 AM, wrote:
On Sunday, October 25, 2015 at 7:12:18 PM UTC-4, Trevor Wilson wrote:
On 26/10/2015 6:32 AM, Gareth Magennis wrote:


"Trevor Wilson" wrote in message ...

On 25/10/2015 11:54 AM, Gareth Magennis wrote:


"Trevor Wilson" wrote in message
...

On 25/10/2015 8:49 AM, Gareth Magennis wrote:


"Trevor Wilson" wrote in message
...

On 24/10/2015 3:07 PM, wrote:
Cylindrical. Axial leads.

Ordered caps for a speaker crossover because the leads had literally
been shaken out of the originals. But I had no luck finding those
bulbs. I would rather not jump it out. I guess I could and just put a
beefier horn in it.


**Select an appropriate sized Polyswitch(tm). Cheap, reliable and
effective.





Polyswitches are not compressors.


**Correct. They're much better. They protect drivers, without
significant audible problems (like compression).






Do you think you would be able to hear such a compression problem?

**Absolutely. I've proven it, under blind test conditions, to clients
who own speakers that are equipped with such things.




OK, but the point I didn't quite make yesterday was that you would only
hear such a compression "problem" if the system was being abused, i.e.
overdriven.
This is when the compression kicks in, to protect the tweeter.

**Well, yes it does. However, it depends on the system. For sound
reinforcement, the compression effects are not likely to be a problem,
though most professional systems use far more sophisticated electronic
compression systems.


To single out the compression as a problem is to completely ignore the
simple fact that this is happening because of a far bigger problem
elsewhere, and the volume needs to be reduced before something blows up.

**In domestic systems a Polyswitch(tm) is, IMO, a better choice.

I located and measured a long, thin filament lamp (which looks like a
baretter). Part # GE1936. Nominally, I would guess it is a 12 Volt lamp.
At 12 Volts, current consumption is 0.75 Amps. Here is the resistance
plot, vs. current:

0.1 A - 1.7 Ohms
0.2 A - 2.15 Ohms
0.3 A - 3.4 Ohms
0.4 A - 6.3 Ohms
0.5 A - 9.68 Ohms
0.6 A - 12.53 Ohms
0.7 A - 15.13 Ohms
0.75 A - 16 Ohms

A Polyswitch(tm) typically exhibits insignificant resistance changes, until
the switching point is reached. They're self-resetting and, provided
Voltage ratings are not exceeded, quite reliable.

--
Trevor Wilson
www.rageaudio.com.au

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

Hi Trevor, I'm not an audio guy. But one thing about polyswitches is that
they do age.. the more times they trip the lower the trip point.
I don't know if that would be an issue where you use them.


**Whilst I have not noticed the effect you describe, I do not suggest
that you are wrong, but it would be instructive to know how many trips
lead to unacceptable aging. That figure would need to be balanced
against the life-span of a baretter.


--
Trevor Wilson
www.rageaudio.com.au

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

wrote:


Hi Trevor, I'm not an audio guy. But one thing about polyswitches is that
they do age.. the more times they trip the lower the trip point.



** Absolutely correct and it can be a real PITA.

Polyswitches go high resistance at about 100C and running one for long periods near the trip temp reduces the current needed to cause tripping.

For predictable long term operation, the trip current needs to be at least double the running current of the device.

FYI: Average DC or RMS AC values must be used in all tests.


.... Phil

On Monday, October 26, 2015 at 4:44:13 PM UTC-4, Trevor Wilson wrote:
On 27/10/2015 3:58 AM, wrote:
On Sunday, October 25, 2015 at 7:12:18 PM UTC-4, Trevor Wilson wrote:
On 26/10/2015 6:32 AM, Gareth Magennis wrote:


"Trevor Wilson" wrote in message ...

On 25/10/2015 11:54 AM, Gareth Magennis wrote:


"Trevor Wilson" wrote in message
...

On 25/10/2015 8:49 AM, Gareth Magennis wrote:


"Trevor Wilson" wrote in message
...

On 24/10/2015 3:07 PM, wrote:
Cylindrical. Axial leads.

Ordered caps for a speaker crossover because the leads had literally
been shaken out of the originals. But I had no luck finding those
bulbs. I would rather not jump it out. I guess I could and just put a
beefier horn in it.


**Select an appropriate sized Polyswitch(tm). Cheap, reliable and
effective.





Polyswitches are not compressors.


**Correct. They're much better. They protect drivers, without
significant audible problems (like compression).






Do you think you would be able to hear such a compression problem?

**Absolutely. I've proven it, under blind test conditions, to clients
who own speakers that are equipped with such things.




OK, but the point I didn't quite make yesterday was that you would only
hear such a compression "problem" if the system was being abused, i.e.
overdriven.
This is when the compression kicks in, to protect the tweeter.

**Well, yes it does. However, it depends on the system. For sound
reinforcement, the compression effects are not likely to be a problem,
though most professional systems use far more sophisticated electronic
compression systems.


To single out the compression as a problem is to completely ignore the
simple fact that this is happening because of a far bigger problem
elsewhere, and the volume needs to be reduced before something blows up.

**In domestic systems a Polyswitch(tm) is, IMO, a better choice.

I located and measured a long, thin filament lamp (which looks like a
baretter). Part # GE1936. Nominally, I would guess it is a 12 Volt lamp.
At 12 Volts, current consumption is 0.75 Amps. Here is the resistance
plot, vs. current:

0.1 A - 1.7 Ohms
0.2 A - 2.15 Ohms
0.3 A - 3.4 Ohms
0.4 A - 6.3 Ohms
0.5 A - 9.68 Ohms
0.6 A - 12.53 Ohms
0.7 A - 15.13 Ohms
0.75 A - 16 Ohms

A Polyswitch(tm) typically exhibits insignificant resistance changes, until
the switching point is reached. They're self-resetting and, provided
Voltage ratings are not exceeded, quite reliable.

--
Trevor Wilson
www.rageaudio.com.au

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

Hi Trevor, I'm not an audio guy. But one thing about polyswitches is that
they do age.. the more times they trip the lower the trip point.
I don't know if that would be an issue where you use them.


**Whilst I have not noticed the effect you describe, I do not suggest
that you are wrong, but it would be instructive to know how many trips
lead to unacceptable aging. That figure would need to be balanced
against the life-span of a baretter.
I wrote an email to littlefuse a while back when I noticed this effect.
I went looking (for where I might have put the data.)

OK here's a link to where I asked the question on Stack exchange.
http://electronics.stackexchange.com...e-ptc-lifetime

Lot's of numbers there.. And I summarize the data from littlefuse.

George H.


--
Trevor Wilson
www.rageaudio.com.au

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

On 28/10/2015 1:47 AM, wrote:
On Monday, October 26, 2015 at 4:44:13 PM UTC-4, Trevor Wilson wrote:
On 27/10/2015 3:58 AM, wrote:
On Sunday, October 25, 2015 at 7:12:18 PM UTC-4, Trevor Wilson wrote:
On 26/10/2015 6:32 AM, Gareth Magennis wrote:


"Trevor Wilson" wrote in message ...

On 25/10/2015 11:54 AM, Gareth Magennis wrote:


"Trevor Wilson" wrote in message
...

On 25/10/2015 8:49 AM, Gareth Magennis wrote:


"Trevor Wilson" wrote in message
...

On 24/10/2015 3:07 PM, wrote:
Cylindrical. Axial leads.

Ordered caps for a speaker crossover because the leads had literally
been shaken out of the originals. But I had no luck finding those
bulbs. I would rather not jump it out. I guess I could and just put a
beefier horn in it.


**Select an appropriate sized Polyswitch(tm). Cheap, reliable and
effective.





Polyswitches are not compressors.


**Correct. They're much better. They protect drivers, without
significant audible problems (like compression).






Do you think you would be able to hear such a compression problem?

**Absolutely. I've proven it, under blind test conditions, to clients
who own speakers that are equipped with such things.




OK, but the point I didn't quite make yesterday was that you would only
hear such a compression "problem" if the system was being abused, i.e.
overdriven.
This is when the compression kicks in, to protect the tweeter.

**Well, yes it does. However, it depends on the system. For sound
reinforcement, the compression effects are not likely to be a problem,
though most professional systems use far more sophisticated electronic
compression systems.


To single out the compression as a problem is to completely ignore the
simple fact that this is happening because of a far bigger problem
elsewhere, and the volume needs to be reduced before something blows up.

**In domestic systems a Polyswitch(tm) is, IMO, a better choice.

I located and measured a long, thin filament lamp (which looks like a
baretter). Part # GE1936. Nominally, I would guess it is a 12 Volt lamp.
At 12 Volts, current consumption is 0.75 Amps. Here is the resistance
plot, vs. current:

0.1 A - 1.7 Ohms
0.2 A - 2.15 Ohms
0.3 A - 3.4 Ohms
0.4 A - 6.3 Ohms
0.5 A - 9.68 Ohms
0.6 A - 12.53 Ohms
0.7 A - 15.13 Ohms
0.75 A - 16 Ohms

A Polyswitch(tm) typically exhibits insignificant resistance changes, until
the switching point is reached. They're self-resetting and, provided
Voltage ratings are not exceeded, quite reliable.

--
Trevor Wilson
www.rageaudio.com.au

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

Hi Trevor, I'm not an audio guy. But one thing about polyswitches is that
they do age.. the more times they trip the lower the trip point.
I don't know if that would be an issue where you use them.


**Whilst I have not noticed the effect you describe, I do not suggest
that you are wrong, but it would be instructive to know how many trips
lead to unacceptable aging. That figure would need to be balanced
against the life-span of a baretter.
I wrote an email to littlefuse a while back when I noticed this effect.
I went looking (for where I might have put the data.)

OK here's a link to where I asked the question on Stack exchange.
http://electronics.stackexchange.com...e-ptc-lifetime

Lot's of numbers there.. And I summarize the data from littlefuse.


**Raychem (the inventor and the only supplier I use) cites something
like 2,000 resets, before significant resistance changes occur.


--
Trevor Wilson
www.rageaudio.com.au

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus