kittys a w____R and so are you :)
You don't.
A step-down transformer lowers the voltage of an AC current. The higher AC current is put through one side and the other side the lower AC current is delivered.
a current flow close to a magnetic source it influence the sources hall effect is a disturbed signal as a function of speed.
in welding machine, the transformer used is basically a current transforrmer. so by changing the tap of secondary side of transformer, we can increase or decrease the current in the transformer.
why does have to short-circuit secondary wire of current transformer ?
Relay are operated by small current /voltage connected to Secondary side of Current Transformer and /or Voltage Transformer. The signal stimulates the magnetic substance nearby with the attracting force. This closes or opens the circuit being used in protection purpose.
It means a signal has no direct (galvanic) connection to the next circuit, rather, the signal is sent (coupled) only through the magnetic field in the transformer. This is used where unwanted DC current would flow, or where a ground loop would result if a direct connection was used.
The difference between current transformer and potential transformer is that the secondary of a current transformer can not be open circuited while under service whereas that of the potential transformer an be open circuited without any damage to the transformer.
It is a transformer with No load attach to it.
Transformer
A current transformer is primarily used at the neutral point of a transformer for earth fault protection. A neutral current transformer will measure any ground fault current which will essentially flow from the star point of the transformer. A fault-detection device other devices is connected to the current transformer and, if the fault current exceeds a certain trigger value, the fault-detection device will give a trip command to an earth-fault relay to disconnect the supply of electricity to the transformer.
A transformer can only increase or decrease the voltage of an alternating current, and it is called step-up transformer or step-down transformer accordingly.