JPH0479197A - Direct current lighting for preheat start fluorescent lamp with high voltage - Google Patents

Abstract

PURPOSE:To eliminate the flickers of a lamp and obtain a large amount of light output by direct current lighting a preheat start type lamp with a voltage from not less than 90V to less than 6000V. CONSTITUTION:In order to direct current light a preheat start type fluorescent lamp 3 with a high lamp voltage (not less than 90V to less than 6000V), an element which has impedance or a circuit 2 is connected to a power supply 7 that can obtain a higher voltage than a lamp start voltage by means of a kick voltage or a power supply with a higher voltage than the lamp start voltage, or a leakage transformer is connected to the power supply. Then, a bridge 6 is used to obtain a direct current voltage and a smoothing capacitor 4 and a smoothing coil 5 are used to obtain a direct current so as to supply it to the fluorescent lamp 3. In this case, the waveform of a load current (lamp current) at a point (B) is the direct current so that flickers can be eliminated. Without having the flickers, a large amount of light output can be obtained.

Description

Detailed Description of the Invention "1" Purpose of the invention (a) Industrial field of application Lighting field (b) Prior art In a conventional AC lighting circuit, the optical output waveform is
It was blinking repeatedly at twice the fundamental frequency.

(c) Problems to be Solved by the Invention A larger light output can be obtained than when using a conventional AC lighting circuit without blinking the lamp.

"2" Configuration of the Invention (a) Means for Solving the Problems In order to start a lamp with a high lamp starting voltage, the power supply voltage is boosted. Alternatively, after obtaining an element with impedance or 9 circuits from a power source higher than the lamp starting voltage, use a bridge to obtain a DC voltage, and then use 7 smoothing capacitors and a smoothing coil to obtain an AC component. A DC voltage with less superimposition is obtained and this is supplied to the fluorescent lamp.

(b) connected to an element or circuit having an impedance at a voltage greater than or equal to the operating lamp starting voltage;
Due to the transient response in the circuit, the load current to the lamp and the charging current to the smoothing capacitor flow, and the terminal voltage of this smoothing capacitor is higher than the terminal voltage of this element or circuit with impedance. When the current becomes large, the current at point A in Figure 1 turns off.

(C) Example The load current waveform at the 8 points in Figure 1 is a direct current as shown in Figure 1 and Figure 2, so it can be seen that there is no flicker. Also, since there is no flicker, we were able to obtain a large light output.

``3'' Effect of the invention Effect of the invention The load current at the 8 points in Figure 1 is a direct current as shown in Figure 1 and Figure 2, so it can be seen that there is no flicker.

Also, since there is no flicker, we were able to obtain a large amount of light pressure.

[Brief explanation of drawings]

Capacitor 2-Transformer 3-Lamp smoothing capacitor 5-Smoothing coil Brillant 7-Power supply 8-Starter noise prevention capacitor (Fig. 1) C゛/l't series

Claims (1)

[Claims] ``1'' In order to light a preheat-start type lamp with a high lamp voltage, after boosting the power supply voltage with a transformer, or by connecting an element or circuit with impedance to a power supply with a voltage higher than the lamp starting voltage. Then, a bridge is used to obtain a DC voltage, and a smoothing capacitor and a smoothing coil are then used to obtain a DC current with less superimposition of AC components, which is then supplied to the lamp.