EP 0422255 B1 19940302 - Electronic ballast.
Title (en)
Electronic ballast.
Title (de)
Elektronisches Vorschaltgerät.
Title (fr)
Ballast électronique.
Publication
Application
Priority
EP 89118713 A 19891009
Abstract (en)
[origin: JPH03138896A] PURPOSE: To provide an electronic auxiliary switching device which can set the dimming of light in a region of specified ratios to normal luminous flux with a simple constitution and surely by increasing a resistance of a discharge section gradually, in the case of increasing the luminance of a fluorescent lamp and setting the resistance to the infinity in cutting off the discharge. CONSTITUTION: Upon adjustment of deviation RAW, which is derived by comparing a desired value SW and an actual value IW, at least one adjustment amount HMG is superposed, and the adjustment amount HMG is made to operate only on a lower limit of a luminance adjustment region of a fluorescent lamp LL. To this end, an auxiliary adjustment amount HMG is derived from a direct voltage at an electrode, which is not connected to a lamp choke coil L1 of the fluorescent lamp LL or from a light-emitting alternating voltage of the fluorescent lamp LL. Thus the switching device can set the dimming of light from the fluorescent lamp using a simple constitution and surely in a region from 10% down to 1% to norminal luminous flux.
IPC 1-7
IPC 8 full level
H05B 41/392 (2006.01)
CPC (source: EP US)
H05B 41/3925 (2013.01 - EP US)
Designated contracting state (EPC)
AT BE CH DE ES FR GB IT LI NL
DOCDB simple family (publication)
EP 0422255 A1 19910417; EP 0422255 B1 19940302; AT E102430 T1 19940315; DE 58907133 D1 19940407; ES 2049790 T3 19940501; HK 123395 A 19950804; JP H03138896 A 19910613; JP H07101638 B2 19951101; US 5066894 A 19911119
DOCDB simple family (application)
EP 89118713 A 19891009; AT 89118713 T 19891009; DE 58907133 T 19891009; ES 89118713 T 19891009; HK 123395 A 19950727; JP 26968890 A 19901009; US 59212590 A 19901003