If it 4 3/4" square by 1 1/2" thick they are popular muffin fans. Companies selling surplus like goldmine-elec.com should have replacement fans.
Norm
:I have a 120V AC fan for my amplifier and it is kind of noisy. I can't figur out or see anywhere to take it apart. It is a ROTRON Whisper fan and is approx 6 x 6 inches and about 1.5 inches thick. I put some sewing machine oil in it and it didn't really help it sounds kind of like barings winding very very faintly though.. It's an Ampeg SVT
I've had poor luck in trying to rebuild small 120-V AC induction motors. But you could tear it apart and see what you can do.
Good Luck!
Doug
:Hi Bubba
:
: If it 4 3/4" square by 1 1/2" thick they are popular muffin fans. Companies selling surplus like goldmine-elec.com should have replacement fans.
:
:Norm
:
::I have a 120V AC fan for my amplifier and it is kind of noisy. I can't figur out or see anywhere to take it apart. It is a ROTRON Whisper fan and is approx 6 x 6 inches and about 1.5 inches thick. I put some sewing machine oil in it and it didn't really help it sounds kind of like barings winding very very faintly though.. It's an Ampeg SVT
Have you looked at radio shack??
They have small 110 to dc votages( looks more like the 110v plug) or their 110 v computer fan.
Marvis
Most muffin fans, as used in computers, are brushless DC motors. They run on DC, e.g. 12 V, not AC. In amps and tube-type radios, there's normally no DC voltage available except the B+ plate supply, which is too high.
:
:I've had poor luck in trying to rebuild small 120-V AC induction motors. But you could tear it apart and see what you can do.
:
:Good Luck!
:Doug
:
:
:
::Hi Bubba
::
:: If it 4 3/4" square by 1 1/2" thick they are popular muffin fans. Companies selling surplus like goldmine-elec.com should have replacement fans.
::
::Norm
::
:::I have a 120V AC fan for my amplifier and it is kind of noisy. I can't figur out or see anywhere to take it apart. It is a ROTRON Whisper fan and is approx 6 x 6 inches and about 1.5 inches thick. I put some sewing machine oil in it and it didn't really help it sounds kind of like barings winding very very faintly though.. It's an Ampeg SVT
Have you looked at radio shack??
They have small 110 to dc votages power supplys( looks more like the 110v plug ) or their 110 v computer fans ?
Marvis
Most muffin fans, as used in computers, are brushless DC motors. They run on DC, e.g. 12 V, not AC. In amps and tube-type radios, there's normally no DC voltage available except the B+ plate supply, which is too high.
:
:I've had poor luck in trying to rebuild small 120-V AC induction motors. But you could tear it apart and see what you can do.
:
:Good Luck!
:Doug
:
:
:
::Hi Bubba
::
:: If it 4 3/4" square by 1 1/2" thick they are popular muffin fans. Companies selling surplus like goldmine-elec.com should have replacement fans.
::
::Norm
::
:::I have a 120V AC fan for my amplifier and it is kind of noisy. I can't figur out or see anywhere to take it apart. It is a ROTRON Whisper fan and is approx 6 x 6 inches and about 1.5 inches thick. I put some sewing machine oil in it and it didn't really help it sounds kind of like barings winding very very faintly though.. It's an Ampeg SVT
Thomas
:
:Have you looked at radio shack??
:They have small 110 to dc votages power supplys( looks more like the 110v plug ) or their 110 v computer fans ?
:
:Marvis
:
:
:
:
:
:
:
:Most muffin fans, as used in computers, are brushless DC motors. They run on DC, e.g. 12 V, not AC. In amps and tube-type radios, there's normally no DC voltage available except the B+ plate supply, which is too high.
::
::I've had poor luck in trying to rebuild small 120-V AC induction motors. But you could tear it apart and see what you can do.
::
::Good Luck!
::Doug
::
::
::
:::Hi Bubba
:::
::: If it 4 3/4" square by 1 1/2" thick they are popular muffin fans. Companies selling surplus like goldmine-elec.com should have replacement fans.
:::
:::Norm
:::
::::I have a 120V AC fan for my amplifier and it is kind of noisy. I can't figur out or see anywhere to take it apart. It is a ROTRON Whisper fan and is approx 6 x 6 inches and about 1.5 inches thick. I put some sewing machine oil in it and it didn't really help it sounds kind of like barings winding very very faintly though.. It's an Ampeg SVT
:Brushless direct current "muffin" fans have only been available recently because of modern circuitry. They accept direct current for their operation, but their operation within does not use direct current. Because there are no brushes and commutator to reverse current to the coils each time the armature moves to the next pole piece, this must be achieved electrically. A very small circuit within the fan does this electrically, and within this fan, you will actually find the permanent magnet on the armature, and the coils around the edge. With special transistorized circuitry, the coils will be energized in just the right way, an alternating current that is in sync with the movement of the armature. 120 volt AC varieties are available, and are readily made (....and yes, they are at Radio Shack). Just like your tube amplifier can only run on direct current, such is with the circuitry of these fans, but just like we have rectifier tubes within our tube amplifiers to convert AC to DC, the 120 volt AC varieties of these "muffin" fans have solid state rectifiers within them.
:
:Thomas
::
::Have you looked at radio shack??
::They have small 110 to dc votages power supplys( looks more like the 110v plug ) or their 110 v computer fans ?
::
::Marvis
::
::
::
::
::
::
::
::Most muffin fans, as used in computers, are brushless DC motors. They run on DC, e.g. 12 V, not AC. In amps and tube-type radios, there's normally no DC voltage available except the B+ plate supply, which is too high.
:::
:::I've had poor luck in trying to rebuild small 120-V AC induction motors. But you could tear it apart and see what you can do.
:::
:::Good Luck!
:::Doug
:::
:::
:::
::::Hi Bubba
::::
:::: If it 4 3/4" square by 1 1/2" thick they are popular muffin fans. Companies selling surplus like goldmine-elec.com should have replacement fans.
::::
::::Norm
::::
:::::I have a 120V AC fan for my amplifier and it is kind of noisy. I can't figur out or see anywhere to take it apart. It is a ROTRON Whisper fan and is approx 6 x 6 inches and about 1.5 inches thick. I put some sewing machine oil in it and it didn't really help it sounds kind of like barings winding very very faintly though.. It's an Ampeg SVT
Things have sure changed. Years ago most of these fans ran on 115 volts AC. Now they have built in circuitry and operate on DC.
You should still be able to find 115 volt AC fans surplus. They were common in computers and rack mounted equipment during 1960's & 1970's.
Norm
:......follow up to what I just said..... If you are having trouble with your brushless muffin fan, it is not likely that this is a mechanical fault. These fans have very fine ball bearings that are lubricated quite well. It is more likely that the transistorized circuitry has gone bad, or the rectifier and filter network, or both. Not an easy repair, as it's all microcircuitry. Best to obtain a new one at a very low price--$30.00 or less, which is hardly worth your effort in repairing the old one.
:
::Brushless direct current "muffin" fans have only been available recently because of modern circuitry. They accept direct current for their operation, but their operation within does not use direct current. Because there are no brushes and commutator to reverse current to the coils each time the armature moves to the next pole piece, this must be achieved electrically. A very small circuit within the fan does this electrically, and within this fan, you will actually find the permanent magnet on the armature, and the coils around the edge. With special transistorized circuitry, the coils will be energized in just the right way, an alternating current that is in sync with the movement of the armature. 120 volt AC varieties are available, and are readily made (....and yes, they are at Radio Shack). Just like your tube amplifier can only run on direct current, such is with the circuitry of these fans, but just like we have rectifier tubes within our tube amplifiers to convert AC to DC, the 120 volt AC varieties of these "muffin" fans have solid state rectifiers within them.
::
::Thomas
:::
:::Have you looked at radio shack??
:::They have small 110 to dc votages power supplys( looks more like the 110v plug ) or their 110 v computer fans ?
:::
:::Marvis
:::
:::
:::
:::
:::
:::
:::
:::Most muffin fans, as used in computers, are brushless DC motors. They run on DC, e.g. 12 V, not AC. In amps and tube-type radios, there's normally no DC voltage available except the B+ plate supply, which is too high.
::::
::::I've had poor luck in trying to rebuild small 120-V AC induction motors. But you could tear it apart and see what you can do.
::::
::::Good Luck!
::::Doug
::::
::::
::::
:::::Hi Bubba
:::::
::::: If it 4 3/4" square by 1 1/2" thick they are popular muffin fans. Companies selling surplus like goldmine-elec.com should have replacement fans.
:::::
:::::Norm
:::::
::::::I have a 120V AC fan for my amplifier and it is kind of noisy. I can't figur out or see anywhere to take it apart. It is a ROTRON Whisper fan and is approx 6 x 6 inches and about 1.5 inches thick. I put some sewing machine oil in it and it didn't really help it sounds kind of like barings winding very very faintly though.. It's an Ampeg SVT