On Wed, 21 Mar 2018 16:53:13 -0400, Jeff Wisnia
wrote:


Will a typical solid state wall mounted dimmer control the speed of a
small 120 volt universal motor (with brushes).

It was previously controlled with a low resistance wire wound variable
resistor which has failed, and If I can use one of the several dimmers I
have on hand that would be great.

Jeff

It should work if it is rated for motors and that horsepower.

On Wed, 21 Feb 2018 21:38:02 -0500, wrote:

On Wed, 21 Mar 2018 16:53:13 -0400, Jeff Wisnia
wrote:


Will a typical solid state wall mounted dimmer control the speed of a
small 120 volt universal motor (with brushes).

It was previously controlled with a low resistance wire wound variable
resistor which has failed, and If I can use one of the several dimmers I
have on hand that would be great.

Jeff

It should work if it is rated for motors and that horsepower.


A universal motor will respond well to a lamp dimmer as long as the
motor starting current does not excede the rating of the dimmer
(usually 600 watts)

On 3/21/2018 4:53 PM, Jeff Wisnia wrote:

Will a typical solid state wall mounted dimmer control the speed of a small 120 volt universal motor (with brushes).

It was previously controlled with a low resistance wire wound variable resistor which has failed, and If I can use one of the several dimmers I have on hand that would be great.

Jeff




Why not grab a fire extinguisher and try it?

David Berkowitz wrote:
On 3/21/2018 4:53 PM, Jeff Wisnia wrote:

Will a typical solid state wall mounted dimmer control the speed of a
small 120 volt universal motor (with brushes).

It was previously controlled with a low resistance wire wound variable
resistor which has failed, and If I can use one of the several dimmers
I have on hand that would be great.

Jeff




Why not grab a fire extinguisher and try it?

Because I wouldn't want to mess up the Orchestrion (Nickleodeon) I
created about 45 years ago by adding instruments to a player piano. See:

https://www.wkrp.org/jeff/Piano/

The present owner is fixing up a few things on that monster which have
deteriorated over the years and I'm trying to help him out with advice
on what to do and how.

The "Roll Box" where the piano roll sits has a small universal motor on
the left inside of the piano case powering it through a belt. That motor
had a rheostat in series with it to adjust the speed of the motor and
hence the tempo of the music.

The rheostat has failed (It measures wide open with an ohmmeter) and
while a similar one could probably still be found I thought I'd ask
about replacing it with a modern light dimmer.

Jeff
--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.

The rheostat has failed (It measures wide open with an ohmmeter) and
while a similar one could probably still be found I thought I'd ask
about replacing it with a modern light dimmer.


no one will be able to tell you for sure

there are leading edge pulse and trailing edge pulse dimmers

there are all kinds of motors

The best answer is to try it.

The worst that could happen is you blow
out the dimmer and it goes to full speed.

mark

On Thu, 22 Feb 2018 13:05:26 -0500, Jeff Wisnia
wrote:



David Berkowitz wrote:
On 3/21/2018 4:53 PM, Jeff Wisnia wrote:

Will a typical solid state wall mounted dimmer control the speed of a
small 120 volt universal motor (with brushes).

It was previously controlled with a low resistance wire wound variable
resistor which has failed, and If I can use one of the several dimmers
I have on hand that would be great.

Jeff




Why not grab a fire extinguisher and try it?

Because I wouldn't want to mess up the Orchestrion (Nickleodeon) I
created about 45 years ago by adding instruments to a player piano. See:

https://www.wkrp.org/jeff/Piano/

The present owner is fixing up a few things on that monster which have
deteriorated over the years and I'm trying to help him out with advice
on what to do and how.

The "Roll Box" where the piano roll sits has a small universal motor on
the left inside of the piano case powering it through a belt. That motor
had a rheostat in series with it to adjust the speed of the motor and
hence the tempo of the music.

The rheostat has failed (It measures wide open with an ohmmeter) and
while a similar one could probably still be found I thought I'd ask
about replacing it with a modern light dimmer.

Safest would be to find a suitable wire wound pot. I don't you would
have trouble with a dimmer but why take a chance on an antique.
What is the current draw of the motor?

wrote:
On Thu, 22 Feb 2018 13:05:26 -0500, Jeff Wisnia
wrote:



David Berkowitz wrote:
On 3/21/2018 4:53 PM, Jeff Wisnia wrote:

Will a typical solid state wall mounted dimmer control the speed of a
small 120 volt universal motor (with brushes).

It was previously controlled with a low resistance wire wound variable
resistor which has failed, and If I can use one of the several dimmers
I have on hand that would be great.

Jeff




Why not grab a fire extinguisher and try it?

Because I wouldn't want to mess up the Orchestrion (Nickleodeon) I
created about 45 years ago by adding instruments to a player piano. See:

https://www.wkrp.org/jeff/Piano/

The present owner is fixing up a few things on that monster which have
deteriorated over the years and I'm trying to help him out with advice
on what to do and how.

The "Roll Box" where the piano roll sits has a small universal motor on
the left inside of the piano case powering it through a belt. That motor
had a rheostat in series with it to adjust the speed of the motor and
hence the tempo of the music.

The rheostat has failed (It measures wide open with an ohmmeter) and
while a similar one could probably still be found I thought I'd ask
about replacing it with a modern light dimmer.

Safest would be to find a suitable wire wound pot. I don't you would
have trouble with a dimmer but why take a chance on an antique.
What is the current draw of the motor?



That was my first suggestion to the present owner and I showed him some
online sites which sell them. It was he who suggested a solid state
dimmer and I told him I'd ask around.

I don't know the motor's current draw but it's pretty small and I'd
expect it would prolly be less than one amp.

I'll see if I can get the present owner to measure it. He does have a
meter and hopefully he can measure ac current with it, or stick a 5 ohm
resistor in series with the motor and measure the voltage drop across it
with his meter.

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.

On Thu, 22 Feb 2018 18:26:02 -0500, Jeff Wisnia
wrote:



wrote:
On Thu, 22 Feb 2018 13:05:26 -0500, Jeff Wisnia
wrote:



David Berkowitz wrote:
On 3/21/2018 4:53 PM, Jeff Wisnia wrote:

Will a typical solid state wall mounted dimmer control the speed of a
small 120 volt universal motor (with brushes).

It was previously controlled with a low resistance wire wound variable
resistor which has failed, and If I can use one of the several dimmers
I have on hand that would be great.

Jeff




Why not grab a fire extinguisher and try it?

Because I wouldn't want to mess up the Orchestrion (Nickleodeon) I
created about 45 years ago by adding instruments to a player piano. See:

https://www.wkrp.org/jeff/Piano/

The present owner is fixing up a few things on that monster which have
deteriorated over the years and I'm trying to help him out with advice
on what to do and how.

The "Roll Box" where the piano roll sits has a small universal motor on
the left inside of the piano case powering it through a belt. That motor
had a rheostat in series with it to adjust the speed of the motor and
hence the tempo of the music.

The rheostat has failed (It measures wide open with an ohmmeter) and
while a similar one could probably still be found I thought I'd ask
about replacing it with a modern light dimmer.

Safest would be to find a suitable wire wound pot. I don't you would
have trouble with a dimmer but why take a chance on an antique.
What is the current draw of the motor?



That was my first suggestion to the present owner and I showed him some
online sites which sell them. It was he who suggested a solid state
dimmer and I told him I'd ask around.

I don't know the motor's current draw but it's pretty small and I'd
expect it would prolly be less than one amp.

I'll see if I can get the present owner to measure it. He does have a
meter and hopefully he can measure ac current with it, or stick a 5 ohm
resistor in series with the motor and measure the voltage drop across it
with his meter.

Jeff

Are there any numbers on the rheostat? Can you measure that with a
meter? Try to figure out if the winding is bad or just the wiper.

wrote:


Are there any numbers on the rheostat? Can you measure that with a
meter? Try to figure out if the winding is bad or just the wiper.

The numbers on the tag on it didn't bring up anything when I Googled
them. And, the tag did read that it was guaranteed until early 1993.

Ive already told him to try measuring what's left there. I said he might
have to pry it open and use ohmmeter probes touched to the resistance
winding to see the resistance of what's left in there.


Jeff
--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.

On Fri, 23 Feb 2018 11:48:12 -0500, Jeff Wisnia
wrote:



wrote:


Are there any numbers on the rheostat? Can you measure that with a
meter? Try to figure out if the winding is bad or just the wiper.

The numbers on the tag on it didn't bring up anything when I Googled
them. And, the tag did read that it was guaranteed until early 1993.

Ive already told him to try measuring what's left there. I said he might
have to pry it open and use ohmmeter probes touched to the resistance
winding to see the resistance of what's left in there.

If you have a rough idea of the resistance and you can judge the
wattage by the size it should not be too hard to find something that
will work.

I use an ordinary cheap and dirty lamp dimmer to control the speed of a used sewing machine motor that is now used in a Van De Graf generator that I built for showing at science fairs. The dimmer does a reasonable job of controlling the motor speed, but the motor is running under a fairly light load, and I don't know how it would doo under a heavy load.

On Fri, 23 Feb 2018 13:09:18 -0800 (PST), wrote:

I use an ordinary cheap and dirty lamp dimmer to control the speed of a used sewing machine motor that is now used in a Van De Graf generator that I built for showing at science fairs. The dimmer does a reasonable job of controlling the motor speed, but the motor is running under a fairly light load, and I don't know how it would doo under a heavy load.
Speed regulation should be better with the dimmer under load than
the rheostat because it is not load dependent like a resistor. It
varies the power by time-slicing the torque instead of reducing it.

Normal dimmers are forward phase control.
A MLV dimmer (for magnetic transformer low foltage lighting) is
symetrical phase controland would likely be more suitable for the
inductive load of a universal motor. A reverse phase controlunit
(spec'd for electronic transformer low voltage lighting) might also be
better than a forward control as it switches on at the zero crossing
point.

Lutron DVLV 10p is symetrical, 1000va, 600p is 600va - add csa suffix
for canada.
DVRP 253P is reverse

The standard dv10p is forward 1000 va


(A PWM controller would be better yet, but is not part of this
discussion)

Also another question. Are you SURE it was a rheostat, and not a
variac??? The variac would be MUCH more suitable than a rheostat for
the application and kinda looks like a rheostat.

I have a 210va Powerstat 10B in my hands as I type this - about 2.75
inches in diameter and 2 inches deep. A WHOLE lot more efficient than
a rheostat.

A guy in Phoenix has one on Flea-bay for $76 USA (plus shipping - $96
to Canada - likely a LOT less within the CUSA.

I'll sell you mine for $75 Canadian Pesos but the shipping would
likely kill you. (The little blighters are not exactly light)

wrote:
On Fri, 23 Feb 2018 11:48:12 -0500, Jeff Wisnia
wrote:



wrote:


Are there any numbers on the rheostat? Can you measure that with a
meter? Try to figure out if the winding is bad or just the wiper.

The numbers on the tag on it didn't bring up anything when I Googled
them. And, the tag did read that it was guaranteed until early 1993.

Ive already told him to try measuring what's left there. I said he might
have to pry it open and use ohmmeter probes touched to the resistance
winding to see the resistance of what's left in there.

If you have a rough idea of the resistance and you can judge the
wattage by the size it should not be too hard to find something that
will work.

Well, the fellow who is getting the Orchestrion back up and running told
me that the motor speed control unit was a rheostat but that an ohmmeter
measurement between the 120 volt input and the output going to the motor
was "wide open", so I assumed it was an open rheostat.

Today he emailed me and told me he'd wired it up between the line
voltage and the motor and found it controlled the motor speed just
fine, so I guess it already is some kind of solid state controller.
Sorry for bothering the group about it.

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.

On Sun, 25 Feb 2018 22:06:43 -0000, Birdbrain Macaw (now "James Wilkinson"),
the pathological attention whore of all the uk ngs, blathered again:



[Grabs nearest dimmer]. One amp, 250 watts.

YOU are certainly the dimmest bulb on all these groups, Birdbrain!

--
AndyW addressing Birdbrain:
"Troll or idiot?...
You have been presented with a viewpoint with information, reasoning,
historical cases, citations and references to back it up and wilfully
ignore all going back to your idea which has no supporting information."
MID:

--
Phil Lee adressing Birdbrain Macaw:
"You are too stupid to be wasting oxygen."
MID:

--
Phil Lee describing Birdbrain Macaw:
"I've never seen such misplaced pride in being a ****ing moronic motorist."
MID:

--
Tony944 addressing Birdbrain Macaw:
"I seen and heard many people but you are on top of list being first class
ass hole jerk. ...You fit under unconditional Idiot and should be put in
mental institution.
MID:

--
Pelican to Birdbrain Macaw:
"Ok. I'm persuaded . You are an idiot."
MID:

On Sun, 25 Feb 2018 22:13:38 -0000, Birdbrain Macaw (now "James Wilkinson"),
the pathological attention whore of all the uk ngs, blathered again:

FLUSH another load of idiotic drivel unread

--
AndyW addressing Birdbrain:
"Troll or idiot?...
You have been presented with a viewpoint with information, reasoning,
historical cases, citations and references to back it up and wilfully
ignore all going back to your idea which has no supporting information."
MID:

--
Phil Lee adressing Birdbrain Macaw:
"You are too stupid to be wasting oxygen."
MID:

--
Phil Lee describing Birdbrain Macaw:
"I've never seen such misplaced pride in being a ****ing moronic motorist."
MID:

Gif: Laughter: https://media.giphy.com/media/VrSZDlpRaHYje/giphy.gif

--
Tony944 addressing Birdbrain Macaw:
"I seen and heard many people but you are on top of list being first class
ass hole jerk. ...You fit under unconditional Idiot and should be put in
mental institution.
MID:

--
Pelican to Birdbrain Macaw:
"Ok. I'm persuaded . You are an idiot."
MID:

On Sun, 25 Feb 2018 22:13:38 -0000, "James Wilkinson Sword"
wrote:

On Thu, 22 Feb 2018 19:10:31 -0000, wrote:

The rheostat has failed (It measures wide open with an ohmmeter) and
while a similar one could probably still be found I thought I'd ask
about replacing it with a modern light dimmer.

no one will be able to tell you for sure

there are leading edge pulse and trailing edge pulse dimmers

there are all kinds of motors

The best answer is to try it.

The worst that could happen is you blow
out the dimmer and it goes to full speed.

I recently tried using a dimmer to blow a 12 volt lightbulb with strange results. The reason I was doing so is I have a 7 watt cat flea killer which uses a 240V lightbulb to attract them, the trouble being the bulbs last about 2 weeks - they die as soon as I or a cat knocks them. So I tried a 7 watt heater, which didn't attract the fleas. I decided they needed the light aswell as the heat, so I thought about a lower voltage car bulb which is used to vibration and has a thicker filament. The trouble is 7 watts is hard to come by and I had to get a dual filament 7/27W bulb, and the only socket I could obtain only lit the 27W filament. I managed to short the two filaments together, but I needed to blow the 27W one. Attaching it straight to the 240V mains caused the bulb to explode, which was no good. The dimmer switch (turned gradually on) immediately blew a 1A mains plug fuse which I thought was odd, as the lamp didn't even light before the fuse blew. A 13A fuse survived and
killed the filament successfully, but I feared I'd break the dimmer by doing this many times. I'm going to use three car batteries to do so in the future (two seems to take forever - double the voltage just make the bulb very hot for 5 minutes before blowing, melting the plastic housing).

Don't they sell "hard service" bulbs there like mechanics used in
their drop lights? (before fluorescent and LEDs that don't burn the
hell out of you)
It is a bulb with a plastic coating on the glass and a special
filament that will put up with just about anything.

Will a typical solid state wall mounted dimmer control the speed of a
small 120 volt universal motor (with brushes).

It was previously controlled with a low resistance wire wound variable
resistor which has failed, and If I can use one of the several dimmers I
have on hand that would be great.

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.