Light control fluorescent lamp and circuit thereof

Abstract

A light control circuit for use in light control fluorescent lamps comprises a filter and rectifier circuit (1), a frequency control and resonant circuit (2) and an ambient brightness signal sampling and control circuit (4); wherein the ambient brightness signal sampling and control circuit (4) advantageously adopts an integrated circuit (IC2) to control or adjust light sensitivity of the light control circuit in an accurate manner and to control the on/off status of the light control circuit in an intelligent way such that the output of the light control circuit is not susceptible to a sudden change of the ambient brightness.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a light control circuit of a light control fluorescent lamp according to a preferred embodiment of the present invention.

FIG. 2 is a circuit diagram of an ambient brightness signal sampling and control circuit of a light control circuit according to a preferred embodiment of the present invention.

FIG. 3 is a circuit diagram of a light control fluorescent lamp according to a preferred embodiment of the present invention.

Claims

1. A light control circuit for use in light control fluorescent lamps comprising: a filter and rectifier circuit (1) coupled to an AC power supply;a frequency control and resonant circuit (2) with its input coupled to an output of the filter and rectifier circuit;an ambient brightness signal sampling and control circuit (4) with its input coupled to the output of the filter and rectifier circuit while its output being coupled to the frequency control and resonant circuit for controlling an output of the same thereby controlling the on/off status of the light control circuit, characterized in that the ambient brightness signal sampling and control circuit (4) advantageously adopts an integrated circuit to control or adjust light sensitivity of the light control circuit in an accurate manner and to control the on/off status of the light control circuit in an intelligent way such that the output of the light control circuit is not susceptible to a sudden change of the ambient brightness.

2. A light control circuit as claimed in claim 1, wherein the ambient brightness signal sampling and control circuit (4) comprises a programmable integrated circuit (IC2) and a plurality of resistors (R10, R11, R12, R13), a photoresistor (SENSOR), a zener diode (Z1), a plurality of capacitors (C11, C13, C14) and a transistor (Q4) coupled correspondingly to respective pins of the programmable integrated circuit (IC2).

3. A light control circuit as claimed in claim 2, wherein the programmable integrated circuit (IC2) is a PIC12F510, PIC12F675, PIC10F220, PIC10F222 or any other functionally equivalent integrated circuit.

4. A light control circuit as claimed in claim 2, wherein the transistor (Q4) is a crystal triode or a MOSFET.

5. A light control circuit as claimed in claim 3, wherein the transistor (Q4) is a crystal triode or a MOSFET.

6. A light control circuit as claimed in claim 1, wherein the ambient brightness signal sampling and control circuit (4) is configured to continuously detect the ambient brightness for a single or multiple times in a predetermined interval and then selectively operates in turnon, intermediate or turnoff modes based on detected brightness thereby controlling the on/off status of the light control circuit correspondingly.

7. A light control circuit as claimed in claim 1, wherein the light control circuit is configured to go through, once coupled to the power supply, a response lag of 1-10 seconds during which the ambient brightness is detected and determined for enabling it to control the on/off status of the light control circuit correspondingly.

8. A light control circuit as claimed in claim 6, wherein the ambient brightness signal sampling and control circuit (4) is configured to operate in the turnon mode or intermediate mode thereby rendering the light control circuit to be turned on or remained on while the ambient brightness being remained below a lower threshold for a specific duration.

9. A light control circuit as claimed in claim 6, wherein the ambient brightness signal sampling and control circuit (4) is configured to operate in the turnoff mode or intermediate mode thereby rendering the light control circuit to be turned off or remained off while the ambient brightness being remained above an upper threshold for a specific duration.

10. A light control circuit as claimed in claim 6, wherein the ambient brightness signal sampling and control circuit (4) is configured to keep the on/off status of the light control circuit unchanged while operating in the intermediate mode.

11. A light control circuit as claimed in claim 8, wherein the specific duration ranges from 3 to 30 seconds.

12. A light control circuit as claimed in claim 9, wherein the specific duration ranges from 3 to 30 seconds.

13. A light control fluorescent lamp, characterized in that it comprises a light control circuit as claimed in claim 1.

14. A light control fluorescent lamp, characterized in that it comprises a light control circuit as claimed in claim 2.

15. A light control fluorescent lamp, characterized in that it comprises a light control circuit as claimed in claim 3.

16. A compact type light control fluorescent lamp as claimed in claim 13, wherein the light control circuit is embedded therein.

17. A compact type light control fluorescent lamp as claimed in claim 14, wherein the light control circuit is embedded therein.

18. A compact type light control fluorescent lamp as claimed in claim 15, wherein the light control circuit is embedded therein.