Calculations
What is the Es when the Ep = 120v with a turn ratio of 1:4?
480v
What type of transformer has no connection between primary and secondary windings?
Isolation transformer
What is another term for tape wound core?
Toroid
When there is no load there is still a small current known as what?
Excitation Current
A secondary is center tapped conductor is know as what?
Neutral Conductor
240v primary and 60v secondary, 5 ohms. What is the turn ratio?
4:1
What type of transformer steps down voltage from the power company lines to a residential building?
Distribution transformer
What is the name of of the core that is made from many sheets of thin metal?
Laminated
What is the current called when you first turn on a transformer?
Inrush Current
True or false. A transformer can change voltage, frequency, and frequency, but not impedance.
False
480v Primary and 120v Secondary, 5 ohms. How many primary amps?
6 Amps
What transformer is used for industrial that steps-down voltage?
Control Transformer
What is a continuous tape wound into a spiral.
Tape-wound core
Flux leakage
What are the dots on a schematic called?
Polarity dots
What is the turn ratio for a 60A primary and a 120v secondary with 6 ohms of impedence?
3:1
What type of transformer has a higher output voltage than input voltage?
What type of core deals with high-voltage distribution transformers?
H-type
When do you add the voltage together.
When the polarities are opposites
When should you subtract volts?
When the polarities are the same
What is the secondary amperage for a transformer with 120v primary and a 240v secondary, with a secondary ohmic value of 5?
48 Amps
Which type of transformer does not isolate the line from the load.
Auto Transformer
True or False. An H-type core is assembled by stacking multiple sheets of metal together, and pressing them into an H shape before laminating them.
False
In an isolation transformer there is the same what?
Volts per turn
What will show insulation problems when an ohmmeter will not?
A megger