Additive and Subtractive Polarity

[foolios]

In the case of step-down transformers:

The polarity between the primary and secondary transformer is subtracting when supplying test voltage to the primary transformer in the case where the H1 is matching the X1.

Now if the polarity markings are wired but switched on the transformers to be additive. Does that mean the step down transformer has become a step up transformer?

 

[vk6kro]

On a normal transformer, polarity won't affect the step-up or step-down action of the transformer.

The ratio of output voltage / input voltage depends on the ratio of secondary to primary turns in the transformer

On an AUTO transformer like this:

The polarity is normally marked but for safety reasons if the input is the mains power supply. It is necessary to get the active and neutral the right way around.
However getting them wrong will not affect the output voltage as long as the turns ratio stays the same.

EDIT:
If you did have two independent windings as in the first case above, but connected one end of the secondary to the top end of the primary, then it would make a difference which end of the secondary you did this with.

The secondary would then add to, or subtract from, the primary (if you took the output from the other end of the secondary) depending on whether it was in phase with it or out of phase.

 

[oswaler]

In the case of step-down transformers, the polarity between the primary and secondary transformer is subtractive. This means that the voltage in the secondary coil is opposite in direction to the voltage in the primary coil. This is important for proper functioning of the transformer and to prevent short circuits.

Switching the polarity markings to be additive does not change the fundamental principle of a step-down transformer. The transformer will still step down the voltage from the primary to the secondary coil. However, the voltage in the secondary coil will now be in the same direction as the voltage in the primary coil.

This change in polarity does not turn the step-down transformer into a step-up transformer. A step-up transformer has a higher voltage in the secondary coil compared to the primary coil, which is achieved through a different design and winding ratio. Simply changing the polarity markings does not alter the transformer's function or design.

It is important to follow the correct polarity markings when wiring a transformer to ensure proper functioning and safety. Switching the polarity markings without proper knowledge and understanding can lead to malfunctions and potential hazards. As a scientist, it is important to carefully consider and understand the principles and design of transformers before making any changes to their wiring or polarity.