On 13 Jun 2005 12:39:44 -0700 wrote:

I need to find a transformer (converter?) that will allow me to
upconvert from 12VAC to 24VAC in order to drive a small motorized
device (50 watts) for continuous duty. I tried using a 110V/220V
'travel' transformer -- it gave me the correct voltage but not enough
output wattage (probably not enough turns on the windings).

The 110/220 transformer had more than enough turns, they were just
wound with wire that was too small for the current that you require.

You could try to find a similar 110/220 transformer with more current
capacity, but this would be big.

An alternative would be to pick up a transformer with 2 12V
secondaries. Ignore the primaries and put the secondaries in series.
Then you apply your 12V between one end and the "center tap" and you
get 24V between the 2 ends, assuming you have the phasing right.

The 2 12V secondaries have to be rated for the current you plan to
draw.

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------

Yet another possibility is to get a 110-to-12 volt transformer and a
110-to-24 volt transformer. Connect the 110 volt windings to each other,
put your 12 volts into the 12 volt winding and take 24 out of the 24
volt winding. I'm sure you're getting the general idea. . .

Roy Lewallen, W7EL

Jim Adney wrote:
On 13 Jun 2005 12:39:44 -0700 wrote:


I need to find a transformer (converter?) that will allow me to
upconvert from 12VAC to 24VAC in order to drive a small motorized
device (50 watts) for continuous duty. I tried using a 110V/220V
'travel' transformer -- it gave me the correct voltage but not enough
output wattage (probably not enough turns on the windings).


The 110/220 transformer had more than enough turns, they were just
wound with wire that was too small for the current that you require.

You could try to find a similar 110/220 transformer with more current
capacity, but this would be big.

An alternative would be to pick up a transformer with 2 12V
secondaries. Ignore the primaries and put the secondaries in series.
Then you apply your 12V between one end and the "center tap" and you
get 24V between the 2 ends, assuming you have the phasing right.

The 2 12V secondaries have to be rated for the current you plan to
draw.

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------

Roy Lewallen wrote:
Yet another possibility is to get a 110-to-12 volt transformer and a
110-to-24 volt transformer. Connect the 110 volt windings to each other,
put your 12 volts into the 12 volt winding and take 24 out of the 24
volt winding. I'm sure you're getting the general idea. . .

Roy Lewallen, W7EL

Jim Adney wrote:

On 13 Jun 2005 12:39:44 -0700 wrote:


I need to find a transformer (converter?) that will allow me to
upconvert from 12VAC to 24VAC in order to drive a small motorized
device (50 watts) for continuous duty. I tried using a 110V/220V
'travel' transformer -- it gave me the correct voltage but not enough
output wattage (probably not enough turns on the windings).



The 110/220 transformer had more than enough turns, they were just
wound with wire that was too small for the current that you require.

You could try to find a similar 110/220 transformer with more current
capacity, but this would be big.

An alternative would be to pick up a transformer with 2 12V
secondaries. Ignore the primaries and put the secondaries in series.
Then you apply your 12V between one end and the "center tap" and you
get 24V between the 2 ends, assuming you have the phasing right.

The 2 12V secondaries have to be rated for the current you plan to
draw.

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------
I did that, but with identical transformers to replace a small
power transformer giving 115v@20ma and [email protected] amp
Used two 6.3v 1A transformers back to back and a bridge
rectifier on the 115v side.