Title:
LOW VOLTAGE LIGHTING CIRCUIT
Document Type and Number:
Japanese Patent JP3081478
Kind Code:
B2
Abstract:
PURPOSE: To provide a protective means which is simple and highly reliable by putting an oscillating transistor in oscillation stop condition by electrically making a two-way thyrister conductive by induced voltage generated in secondary coils at the time of load side short circuit.
CONSTITUTION: When a load side is short-circuited, large current flows in primary coils of an output transformer T12 and an oscillation transformer T11 and high voltage is induced in secondary coils L2-L4 of the transformer T11. The voltage induced between the coils L4, L2 is applied to a gate of thyrister Q4 and in the case the voltage value exceeds a prescribed value, the thyrister Q4 is electrically conductive and sets the base potential of the transistor Q2 to be a value at which the transistor Q2 can not work. When the transistor Q2 stops oscillating, the charge of the capacitor C3 is discharged while being applied to a triger element Q3 through resistors R2, R4. In this case, the charged voltage of the capacitor C3 is previously set to be high and thus Q3 is electrically conductive without sending a triger output. As a result, Q2 keeps oscillation stop condition.
Inventors:
Takeshi Yamada
Yuji Mineta
Yoshihiko Fujii
Yuji Mineta
Yoshihiko Fujii
Application Number:
JP29379694A
Publication Date:
August 28, 2000
Filing Date:
November 02, 1994
Export Citation:
Assignee:
Tokyo Special Electric Wire Co., Ltd.
International Classes:
H05B41/24; H02M7/48; H02M7/5383; H05B41/232; H05B41/282; (IPC1-7): H05B41/24; H02M7/48; H02M7/5383; H05B41/232; H05B41/282
Domestic Patent References:
| JP297279A | ||||
| JP62163293A | ||||
| JP5184160A | ||||
| JP55128400U |