
62 Cells, batteries and transformers
-H
Diagram 73 Hysteresis loop for transformer core
used in installation work in appliances such as battery chargers and/or
alarm circuits. Rectifiers are discussed in greater detail in Volume 3.
Points to note (I.E.E. Regulations)
1.
Step-up transformers forming part of a consumer installation
should have a linked switch provided for isolating the transformer
from the supply.
2.
Portable appliances using extra-low voltage, i.e. train sets should
not be supplied from an auto-transformer.
3.
The common terminal of an auto-transformer should be connected
to the neutral conductor (Diagram 69).
4.
Hand-held appliance ...