R
[email protected]
- Jan 1, 1970
- 0
At first blush, it seems like you should be able to use a power
transformer as either step-down or step-up, simply by feeding the
input into either the primary or secondary. However, is this really
the case? For example, consider one of those pole transformers that
normally step down, say, 12kV to 220V. If the secondary is not
connected to anything, I would expect the primary current to be quite
small. However, if you were to feed 220V into the secondary with the
primary open, wouldn't quite a bit of current be drawn by the 220V
secondary? (I've never tried this, I'm running on intuition here, so
I would welcome any insight.)
A similar situation: one of those Weller soldering guns. It has a
transformer with many turns on the 120V primary, and a ONE-turn heavy
copper secondary going to the tip. Surely if you reverse that and
feed in 1V (or whatever the secondary voltage is) it will be almost a
direct short at 60Hz, even if the primary is unloaded?
Is my intuition right, or am I totally off base here?
If I am right, what is it that makes the transformer asymmetrical?
That is, different when used as step-up or step-down? How would a
step-up transformer that is meant to convert 220V to 12kV differ in
construction from the step-down pole transformer, and why?
Robert
transformer as either step-down or step-up, simply by feeding the
input into either the primary or secondary. However, is this really
the case? For example, consider one of those pole transformers that
normally step down, say, 12kV to 220V. If the secondary is not
connected to anything, I would expect the primary current to be quite
small. However, if you were to feed 220V into the secondary with the
primary open, wouldn't quite a bit of current be drawn by the 220V
secondary? (I've never tried this, I'm running on intuition here, so
I would welcome any insight.)
A similar situation: one of those Weller soldering guns. It has a
transformer with many turns on the 120V primary, and a ONE-turn heavy
copper secondary going to the tip. Surely if you reverse that and
feed in 1V (or whatever the secondary voltage is) it will be almost a
direct short at 60Hz, even if the primary is unloaded?
Is my intuition right, or am I totally off base here?
If I am right, what is it that makes the transformer asymmetrical?
That is, different when used as step-up or step-down? How would a
step-up transformer that is meant to convert 220V to 12kV differ in
construction from the step-down pole transformer, and why?
Robert