Mounting toroidal transformers

[Stoatgobbler]

Hi there,

Does anyone know if there is a reason why I cannot mount toroidal
transformers one on top of another (stacking them) with a single metal
mounting bolt going through both? I can't see anything on the web which
suggests I don't do this.

Stoat

 

[Shaun]

Hi there,

Does anyone know if there is a reason why I cannot mount toroidal
transformers one on top of another (stacking them) with a single metal
mounting bolt going through both? I can't see anything on the web which
suggests I don't do this.

Stoat

The magnetic flux from one transformer could interact with the other one
being that they are that close to eachother. I've seen cases where cases
where the toroidal transformer was made up of two or more rings stacked one
on top of the other, and then the wire wrapped around them all.

I used to repair industrial electronics and I've never seen someone stack
toroidal transformers before. They mount them side by side with clearance.

Shaun

 

[Stoatgobbler]

The magnetic flux from one transformer could interact with the other one
being that they are that close to eachother. I've seen cases where cases
where the toroidal transformer was made up of two or more rings stacked one
on top of the other, and then the wire wrapped around them all.

I used to repair industrial electronics and I've never seen someone stack
toroidal transformers before. They mount them side by side with clearance.

Shaun

Well, I've mounted them on top of one another, I can't find any problem
with it.....however....I've got I've used these toroids to create two
split rail power supplies (two independent +22v - 0 - -22v supplies) and
to make them independant I've "lifted" the 0v commons from the chassis
earth via 60ohm resistors. The greater the current I pull out of the
power supply the greater the potential difference across the 60ohm
resistor. when I pull 1.1A from the power supply then I have nearly 17v
across the 60ohm resistor. This voltage does not seem to vary with
raising the upper toroidal away from the lower so I don't think its to
do with this.

I've never "played" with this, I did expect a voltage across it (due to
eddy currents within the transformer?) but I thought it would be
nominal....0.25A is not nominal.

Is this normal?

 

[Shaun]

Well, I've mounted them on top of one another, I can't find any problem
with it.....however....I've got I've used these toroids to create two
split rail power supplies (two independent +22v - 0 - -22v supplies) and
to make them independant I've "lifted" the 0v commons from the chassis
earth via 60ohm resistors. The greater the current I pull out of the power
supply the greater the potential difference across the 60ohm resistor.
when I pull 1.1A from the power supply then I have nearly 17v across the
60ohm resistor. This voltage does not seem to vary with raising the upper
toroidal away from the lower so I don't think its to do with this.

I've never "played" with this, I did expect a voltage across it (due to
eddy currents within the transformer?) but I thought it would be
nominal....0.25A is not nominal.

Is this normal?

I don't have an answer for you about that.

Shaun

 

[[email protected]]

The magnetic flux from one transformer could interact with the other one
being that they are that close to eachother.  I've seen cases where cases
where the toroidal transformer was made up of two or more rings stacked one
on top of the other, and then the wire wrapped around them all.

I used to repair industrial electronics and I've never seen someone stack
toroidal transformers before.  They mount them side by side with clearance.

Shaun

Consider placing a soft steel washer just larger in diameter than the
toroid between each.

 

[[email protected]]

Hi there,

Does anyone know if there is a reason why I cannot mount toroidal
transformers one on top of another (stacking them) with a single metal
mounting bolt going through both? I can't see anything on the web which
suggests I don't do this.

Stoat

The strongest magnetic field is produced in a rod shape through the
center of the toroid, when stacking them make sure to orient them both
with the same side facing up, or to put it another way, opposite sides
facing each other if non-horizontally mounted. If they are ran near
capacity, they will stay cooler if you do not block one of the larger
sides with another (heat-producing) transformer.