High-precision led control circuit, method and led driver thereof
US-2015382418-A1 · Dec 31, 2015 · US
Lighting device and luminaire
US9648681B2 · US · B2
| Field | Value |
|---|---|
| Publication number | US-9648681-B2 |
| Application number | US-201615200289-A |
| Country | US |
| Kind code | B2 |
| Filing date | Jul 1, 2016 |
| Priority date | Jul 9, 2015 |
| Publication date | May 9, 2017 |
| Grant date | May 9, 2017 |
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- Title
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Abstract
Official abstract text for this publication.
A lighting device includes: a signal converting circuit which receives a dimming signal that is a rectangular voltage signal, and converts the dimming signal to a DC voltage signal corresponding to a duty ratio of the dimming signal; and a power supply circuit which receives an AC voltage and outputs DC current having a current value corresponding to the DC voltage signal. The signal converting circuit includes a resistor-capacitor (RC) circuit which integrates a signal corresponding to the dimming signal by way of charging and discharging to produce the DC voltage signal, and a time constant of the RC circuit during charging is greater than a time constant of the RC circuit during discharging.
First claim
Opening claim text (preview).
What is claimed is: 1. A lighting device, comprising: a signal converting circuit which receives a dimming signal that is a rectangular voltage signal, and converts the dimming signal to a DC voltage signal corresponding to a duty ratio of the dimming signal; and a power supply circuit which receives an AC voltage and outputs DC current having a current value corresponding to the DC voltage signal, wherein the signal converting circuit includes a resistor-capacitor (RC) circuit which integrates a signal corresponding to the dimming signal by way of charging and discharging to produce the DC voltage signal, and a time constant of the RC circuit during charging is greater than a time constant of the RC circuit daring discharging. 2. The lighting device according to claim 1 , wherein the time constant of the RC circuit during discharging is 10 times or greater than a period of the dimming signal. 3. The lighting device according to claim 1 , wherein the RC circuit includes; a first resistor; a second resistor connected in series to the first resistor; a capacitor connected in series to the second resistor; and a transistor connected in parallel to a series circuit including the second resistor and the capacitor, wherein the signal corresponding to the dimming signal is coupled to a base of the transistor, and the DC voltage signal is derived from a voltage across the capacitor. 4. The lighting device according to claim 3 , wherein the RC circuit includes a rectifying element connected in parallel to the second resistor, and the first resistor has a greater resistance value than a resistance value of the second resistor. 5. The lighting device according to claim 3 , wherein a rectifying element is not disposed between the transistor and the capacitor. 6. The lighting device according to claim 1 , wherein the current value of the DC current outputted by the power supply circuit has a positive correlation with a voltage value of the DC voltage signal. 7. A luminaire comprising: the lighting device according to claim 1 ; and a solid-state light-emitting element which receives the DC current outputted from the lighting device.
Assignees
Inventors
Classifications
by timing means · CPC title
- H05B33/0815Primary
Electricity · mapped topic
Electricity · mapped topic
Electricity · mapped topic
- H05B45/10Primary
Controlling the intensity of the light · CPC title
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- What does patent US9648681B2 cover?
- A lighting device includes: a signal converting circuit which receives a dimming signal that is a rectangular voltage signal, and converts the dimming signal to a DC voltage signal corresponding to a duty ratio of the dimming signal; and a power supply circuit which receives an AC voltage and outputs DC current having a current value corresponding to the DC voltage signal. The signal converting…
- Who is the assignee on this patent?
- Panasonic Ip Man Co Ltd
- What technology area does this patent fall under?
- Primary CPC classification H05B33/0815. Mapped technology areas include Electricity.
- When was this patent published?
- Publication date Tue May 09 2017 00:00:00 GMT+0000 (Coordinated Universal Time) (B2). Legal status and post-grant events are not shown on this page.
- What related patents are in patentsdb?
- We list 8 related publications on this page (citations in our corpus or others sharing the same primary CPC).