Where Do You Get Those Light Bulbs In Series With Tweeters ?

Trevor Wilson <trevor@spamblockrageaudio.com.au> wrote:
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.
Click to expand...

For what it's worth, this lamp appears to be a 22 V, 1 A nominal rating.

http://www.donsbulbs.com/cgi-bin/r/b.pl/1936~general-electric.html

Standard disclaimers apply: I don't get money or other consideration
from any companies mentioned.

Matt Roberds
 
On 27/10/2015 3:58 AM, ggherold@gmail.com 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 news:d930b6Fctf6U1@mid.individual.net...

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


"Trevor Wilson" wrote in message
news:d92kb7Fa87iU3@mid.individual.net...

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


"Trevor Wilson" wrote in message
news:d92c5nF8av2U3@mid.individual.net...

On 24/10/2015 3:07 PM, jurb6006@gmail.com 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.
Click to expand...

**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
 
On 27/10/2015 11:08 AM, mroberds@att.net wrote:
Trevor Wilson <trevor@spamblockrageaudio.com.au> wrote:
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.

For what it's worth, this lamp appears to be a 22 V, 1 A nominal rating.

http://www.donsbulbs.com/cgi-bin/r/b.pl/1936~general-electric.html

Standard disclaimers apply: I don't get money or other consideration
from any companies mentioned.

Matt Roberds
Click to expand...

**Nice catch. That is, indeed, the lamp. At 22 Volts, current
consumption is 1.04 Amps. Near enough.

--
Trevor Wilson
www.rageaudio.com.au

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
 
gghe...@gmail.com 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.
Click to expand...

** 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, ggherold@gmail.com 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 news:d930b6Fctf6U1@mid.individual.net...

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


"Trevor Wilson" wrote in message
news:d92kb7Fa87iU3@mid.individual.net...

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


"Trevor Wilson" wrote in message
news:d92c5nF8av2U3@mid.individual.net...

On 24/10/2015 3:07 PM, jurb6006@gmail.com 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.
Click to expand...
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/questions/121845/polyfuse-resettable-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
Click to expand...
 
On 28/10/2015 1:47 AM, ggherold@gmail.com wrote:
On Monday, October 26, 2015 at 4:44:13 PM UTC-4, Trevor Wilson wrote:
On 27/10/2015 3:58 AM, ggherold@gmail.com 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 news:d930b6Fctf6U1@mid.individual.net...

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


"Trevor Wilson" wrote in message
news:d92kb7Fa87iU3@mid.individual.net...

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


"Trevor Wilson" wrote in message
news:d92c5nF8av2U3@mid.individual.net...

On 24/10/2015 3:07 PM, jurb6006@gmail.com 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/questions/121845/polyfuse-resettable-ptc-lifetime

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

**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
 
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