Resistive-type heating appliances and incandescent lamps (conventional or halogen)
See also "Lighting circuits" for more details
The current demand of a heating appliance or an incandescent lamp is easily obtained from the nominal power Pn quoted by the manufacturer (i.e. cos φ = 1) (see Fig. A5).
|Nominal power (kW)||Current demand (A)|
The currents are given by:
where U is the voltage between the terminals of the equipment.
For an incandescent lamp, the use of halogen gas allows a more concentrated light source. The light output is increased and the lifetime of the lamp is doubled.
Note: At the instant of switching on, the cold filament gives rise to a very brief but intense peak of current.
- Ia in amps; U in volts. Pn is in watts. If Pn is in kW, then multiply the equation by 1,000.