Method of Brightness Control of Fluorescent Lamp and Device for Brightness Control of Fluorescent Lamp

This invention relates to the method of brightness control of a fluorescent lamp and the device for brightness control of a fluorescent lamp,

There is known the method of brightness control of a fluorescent lamp in which controlling of brightness is executed by installation of an additional controlling wire. There is known also the method of brightness control, in which a signal from a dimmer, being a part of sinusoid and having appropriate make-time is transforming. ^• This signal is transformed in a way that voltage from a dimmer is averaged. Current intensity is controlled as a function of this averaged voltage .

There are known devices for brightness control of a fluorescent lamp equipped with an additional controlling wire. There are also- known devices for brightness control of a fluorescent lamp equipped with a circuit averaging voltage from a dimmer.

The method of brightness control of a fluorescent lamp is executed on the basis of the make-time of a dimmer. The make- time of a dimmer is transformed into a digital, signal having higher frequency than power frequency. Current intensity of a fluorescent lamp is controlled on the basis of a digital

signal. The measuring of the make-time of a dimmer is executed when additional load is connected. The make-time of a dimmer is transformed taking into account characteristics of a dimmer. The make-time of a dimmer is transformed, taking into account characteristics of brightness of a fluorescent lamp, as a function of current intensity. The device for brightness control of a fluorescent lamp is equipped ^• with a circuit for measuring of the make-time of a dimmer and a circuit generating digital signal having higher frequency than power frequency. The device is equipped with resonant circuit controlling current intensity of a fluorescent lamp on the basis ^' of a digital signal. The device is equipped with additional load connecting temporarily for the moment of- measuring of the make-time. The device is an element of a compact fluorescent lamp or an element of a fitting of a fluorescent lamp.

The method of brightness control of a fluorescent lamp and device for brightness control of a fluorescent lamp allow controlling of brightness of a fluorescent lamp using any dimmer. The invention allows stable work of a fluorescent lamp .

The example of the object of invention is shown on the drawing, in which waveforms of a dimmer, the make-times relating to signal of a dimmer, digital signals having fixed frequency, signals controlling resonant circuit and level of brightness are exhibited.

For example, the. method of brightness control of a fluorescent lamp begins with generating signal by a dimmer. The signal generated by a dimmer has a form of a part of sinusoid. Time of the part of sinusoid depends on setting of dimmer. Measuring of the make-time . of a dimmer is made digitally with connected additional load. The make-time of _^ a dimmer is transformed by microprocessor circuit into digital signal. The digital signal has 10 kHz frequency. The time of

high state will be longer if the make-time of dimmer is longer. The frequency of resonant circuit and current intensity of a fluorescent lamp is controlled by the time of high state. The control is corrected by characteristic of brightness of a fluorescent lamp in function of current intensity.

In the first example, the device for brightness control of a fluorescent lamp is a part of a compact fluorescent lamp. The device has the circuit measuring the make-time from a dimmer and the circuit connecting temporarily additional load. The device has also the circuit generating 10 kHz signal and the circuit regulating current intensity of a fluorescent lamp with correction of characteristics of a dimmer and a fluorescent lamp.

In the second example, the device for brightness control of a fluorescent lamp is a part of a fitting of a fluorescent lamp. The device has the circuit measuring the make-time from a dimmer and the circuit connecting temporarily additional load. The device has also the circuit generating 10 kHz signal and the circuit regulating current intensity of a fluorescent lamp with correction of characteristics of. a dimmer and a fluorescent lamp.