Title:
INCANDESCENT LAMP DIMMING DEVICE
Document Type and Number:
Japanese Patent JP3536933
Kind Code:
B2
Abstract:
PURPOSE: To suppress heating and prevent sound noise by bearing most of the on-segment of each half cycle with a main switching circuit made of thyristors having low on-resistance, and bearing the steep rise portion with the switching element of an auxiliary switching circuit in a dimming device.
CONSTITUTION: The output of a power transformer 21 is inputted to a timing generation section 22, and a zero cross point is detected by a zero cross detecting circuit 23. A counter 24 measures the time corresponding to the level of the dimming signal each time the zero cross point is detected, outputs it to an inclination controller 26, and outputs the thyristor ignition pulse to thyristors 13, 14. An inclination function generation section 27 outputs the lamp function wave-form based on the output signal from a generation section 22 at the inclination controller 26, it is compared with the output voltage by a comparison controller 28, and the coincidence signal is outputted to the base of an IGBT 19. The output voltage to an incandescent lamp 12 is the sum of the voltage by the linear operation of the IGBT 19 and the voltage by the alternate ignition of the thyristors 13, 14. Most of the on-segment in each half cycle is borne by the thyristors 13, 14 having low on-resistance.
Inventors:
Sasai, Toshihiko
Nagasaki, Fumihiko
Nagasaki, Fumihiko
Application Number:
JP6083994A
Publication Date:
June 14, 2004
Filing Date:
March 30, 1994
Export Citation:
Assignee:
TOSHIBA LIGHTING & TECHNOL CORP
International Classes:
F21S10/00; F21V23/00; H05B37/02; H05B39/08; (IPC1-7): H05B39/08; F21S10/00; F21V23/00; H05B37/02