Separated Extra-low Voltage (SELV) Transformers the primary winding
and the secondary winding double wound transformer have sepa-
rate connection earth, then the output the transformer effectively
isolated from the input since the only connection between the primary
and secondary windings the magnetic flux the transformer core. The voltmeter calibrated take account the turns ratio
of the transformer, that the voltmeter displays the actual supply voltage.24. Such
a transformer would give very safe electrical supply which might suit-
able for bathroom equipment such shaver sockets and construction site
110V tools, providing that all other considerations are satisfied, such as
water ingress, humidity, protection and robust construction.
A lamp device for converting electrical energy into light energy.
Fluorescent lamps are linear arc tubes, internally coated with fluorescent
powder, containing little low pressure mercury vapour and argon gas. 10. Fluorescent tubes operate the ‘dis-
charge’ principle; that is, the excitation gas within glass tube. essentially the ‘light fitting’. The
lamp construction shown Fig.
They form the basic principle most energy efficient lamps.Alternating current theory and electrical machines
215
A Voltage Transformer (or VT) has the main supply voltage connected the
primary winding the transformer and the voltmeter connected the sec-
ondary winding.23
A step transformer
Definition
A luminaire equipment which sup-
ports electric lamp and distributes
or filters the light created the lamp. They
are cooler operation and very efficient converting electricity into light.
Fluorescent luminaires
A luminaire equipment which supports electric lamp and distributes
or filters the light created the lamp.
.
Primary coil
500 turns
Np 500
Magnetic flux
1:2
Turns ratio
Vp 230V supply 460V output
Secondary coil
1000 turns
Ns 1000
L
o
a
d
FIGURE 10.
Passing current through the electrodes the tube produces cloud
of electrons that ionize the mercury vapour and the argon the tube,
Key Fact
Energy efficiency
● fluorescent lamps and CFLs
(compact fluorescent lamps) are
energy efficient lamps
● they give more light out for every
electrical, watt input.
A lamp device for converting elec-
trical energy into light energy. There
are many types lamps. General lighting service (GLS) lamps and tung-
sten halogen lamps use very hot wire filament create the light and so
they also become very hot use
