Drive circuit, illumination light source, and lighting apparatus
First Claim
Patent Images
1. A drive circuit for turning on a light-emitting element, the drive circuit comprising:
- a self-excited inverter which supplies power to the light-emitting element,wherein the self-excited inverter includes a thermistor, and depending on temperature dependency of the thermistor, supplies a first power value to the light-emitting element when a temperature is a first temperature, and a second power value to the light-emitting element when a temperature is a second temperature higher than the first temperature,the self-excited inverter is a half-bridge self-excited inverter,the thermistor has a positive temperature characteristic,the self-excited inverter further includes;
a first switching element and a second switching element which are connected in series and alternately perform switching operations;
a first resistor connected to a base of the first switching element; and
a second resistor connected to a base of the second switching element,the thermistor includes a first thermistor and a second thermistor,the first thermistor is connected in parallel to the first resistor, andthe second thermistor is connected in parallel to the second resistor.
3 Assignments
0 Petitions
Accused Products
Abstract
A drive circuit is a drive circuit for turning on an LED and includes a self-excited inverter supplying power to the LED, wherein the self-excited inverter includes thermistors, and supplies, depending on temperature dependency of the thermistors, the first power value to the LED when a temperature is the first temperature, and the second power value to the LED when a temperature is the second temperature higher than the first temperature, and the second power value is smaller than the third power value that a circuit which is not provided with the thermistors and supplies the first power value to the LED when the temperature is a first temperature supplies to the LED when a temperature is the second temperature.
13 Citations
6 Claims
-
1. A drive circuit for turning on a light-emitting element, the drive circuit comprising:
-
a self-excited inverter which supplies power to the light-emitting element, wherein the self-excited inverter includes a thermistor, and depending on temperature dependency of the thermistor, supplies a first power value to the light-emitting element when a temperature is a first temperature, and a second power value to the light-emitting element when a temperature is a second temperature higher than the first temperature, the self-excited inverter is a half-bridge self-excited inverter, the thermistor has a positive temperature characteristic, the self-excited inverter further includes; a first switching element and a second switching element which are connected in series and alternately perform switching operations; a first resistor connected to a base of the first switching element; and a second resistor connected to a base of the second switching element, the thermistor includes a first thermistor and a second thermistor, the first thermistor is connected in parallel to the first resistor, and the second thermistor is connected in parallel to the second resistor. - View Dependent Claims (3, 4)
-
-
2. A drive circuit for turning on a light-emitting element, the drive circuit comprising:
-
a self-excited inverter which supplies power to the light-emitting element, wherein the self-excited inverter includes a thermistor, and depending on temperature dependency of the thermistor, supplies a first power value to the light-emitting element when a temperature is a first temperature, and a second power value to the light-emitting element when a temperature is a second temperature higher than the first temperature, the self-excited inverter is a half-bridge self-excited inverter, the thermistor has a positive temperature characteristic, the self-excited inverter further includes; a first switching element and a second switching element which are connected in series and alternately perform switching operations; a first resistor connected to an emitter of the first switching element; and a second resistor connected to an emitter of the second switching element, the thermistor includes a first thermistor and a second thermistor, the first thermistor is connected in parallel to the first resistor, and the second thermistor is connected in parallel to the second resistor. - View Dependent Claims (5, 6)
-
Specification
-
- Resources
Litigation Campaign Assessment
Thank you for your request. You will receive a custom alert email when the Litigation Campaign Assessment is available.
×
-
Current AssigneePanasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
-
Original AssigneePanasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
-
InventorsFujita, Hiroshi, Utsubo, Atsushi, Itoh, Kazuhiko
-
Primary Examiner(s)Tran, Thuy Vinh
-
Assistant Examiner(s)Kaiser, Syed M
-
Application NumberUS14/161,409Publication NumberTime in Patent Office552 DaysField of Search315/291, 315/200.R, 315/118, 315/224, 363/24.1US Class Current1/1CPC Class CodesH05B 45/30 Driver circuitsH05B 45/39 Circuits containing inverte...
