Patent Application
20120163827
1. Technical Field
The present disclosure relates to an infrared remote control unit and a lighting system having the control unit.
2. Description of Related Art
In daily life, turning off/on the light is manually implemented by depressing button(s). However, it is inconvenient if the button(s) is(are) away from the bed when people have to get up at night.
Referring to
The infrared remote control 12 includes a key encoder 121, a first bipolar junction transistor (BJT) 122, an infrared light emitting diode 123, a clock circuit 124, and a keypad 125.
The key encoder 121 may be any available commercial encoders, such as the SANYO LC7461. The keypad 125 may include keys for adjusting brightness of the lamp 17, an on/off key, a timing key, and/or a reset key, etc. For example, the keypad 125 includes a number of keys, each of which can implement a different brightness level of the lamp 17.
A base of the first bipolar junction transistor 122 is connected to an OUT pin of the key encoder 121 (an output pin for transmit LED drive) via a first resistor 127. An emitter of the first bipolar junction transistor 122 is grounded. A collector of the first bipolar junction transistor 122 is connected to a cathode of the infrared light emitting diode 123. When a key of the keypad 125 is depressed, the key encoder 121 triggers the first bipolar junction transistor 122, thereby driving the infrared light emitting diode 123 to emit infrared light correspondingly.
An anode of the infrared light emitting diode 123 is connected to a power supply terminal VCC. A C5 pin, a VDD pin, and a TEST pin of the key encoder 121 are connected to a node between the anode of the infrared light emitting diode 123 and the power supply terminal VCC. A capacitor 126 is connected between the node and ground. The capacitor 126 is capable of wave-filtering to stabilize voltage applied to the infrared light emitting diode 123.
The clock circuit 124 includes an oscillator 1241 having a frequency of 455 KHz, in one example. Two terminals of the oscillator 1241 are connected to an OSC1 pin and an OSC2 pin of the key encoder 121, respectively. The OSC1 pin and the OSC2 pin of the key encoder 121 are input and output pins for ceramic resonator-used oscillation. A frequency used for infrared communication is about 37.9 KHz, which is obtained by dividing 455 KHz by twelve.
The infrared processing unit 11a includes an infrared receiver 13, a processor 11, a display 14, a switch control 15, and a power-failure protection unit 16.
The infrared receiver 13 may be a TSOP1838 infrared receiver, in one example. The processor 11 may be an ATMEL AT89C2051 microcomputer, in one example. An output pin of the infrared receiver 13 is connected to a RXD (serial input port) pin of the processor 11. A GND pin of the infrared receiver 13 is grounded. A Vcc pin of the infrared receiver 13 is connected to a power supply terminal VCC. The Vcc pin of the infrared receiver 13 is also connected to ground via a capacitor 131 to perform wave filtering.
The display 14 includes a driver 141 and a nixie tube 142. The driver 141 may be a TEXAS INSTRUMENTS SN74HC574, in one example. The driver 141 is connected to a P0 pin of the processor 11. The nixie tube 142 is a common-cathode nixie tube. The processor 11 reads a timing signal, indicating duration after which a predetermined function is performed, output from the infrared remote control 12 and drives the driver 141 to control the nixie tube 142 to display the duration. It is to be understood that in alternative embodiments, the driver 141 may be connected to a P1 pin or a P2 pin of the processor 11.
An oscillator frequency of the processor 11 is about 11.0592 Mhz, in one example. The processor 11 is configured to read instructions contained in the infrared light emitted from the infrared receiver 13 and save the instructions in the power-failure protection unit 16. The power-failure protection unit 16 includes an electrically erasable and programmable read only memory (EEPROM), such as an ATMEL AT24C01, in one example. The AT24C01 provides 1024 bits of serial electrically erasable and programmable read only memory organized as 128 words of 8 bits each. The AT24C01 is accessed via a 2-wire serial interface. The AT24C01 includes a serial data (SDA) pin and a serial clock input (SCL) pin. The SCL pin is used to positive edge clock data into each EEPROM device and negative edge clock data out of each device. The SDA pin is bidirectional for serial data transfer and is open-drain driven and may be wire-ORed with any number of other open-drain or open collector devices. The SDA pin is normally pulled high with an external device. Data on the SDA pin may change only during SCL low time periods. Data changes during SCL high periods will indicate a start or stop condition as defined below. START CONDITION: a high-to-low transition of SDA with SCL high is a start condition which must precede any other command STOP CONDITION: a low-to-high transition of SDA with SCL high is a stop condition which terminates all communications and after a read sequence, the stop command will place the EEPROM in a standby power mode.
The switch control 15 includes an optical coupler 151, a silicon controlled rectifier 152, a second bipolar junction transistor 153 and a second resistor 154. The base of the second bipolar junction transistor 153 is connected to a P1.3 pin of the processor 11 via the second resistor 154. The optical coupler 151 is a MOTOROLA MOC3081, in one example. The collector of the second bipolar junction transistor 153 is connected to a cathode of the optical coupler 151. An anode of the optical coupler 151 is connected to a power supply terminal VCC. A first main terminal of the optical coupler 151 is connected to the live wire of the household power 18 via the lamp 17.
The silicon controlled rectifier 152 is a bidirectional thyristor (TRIAC), in one example. A gate of the rectifier 152 is connected to a second main terminal of the optical coupler 151. A first terminal T1 of the rectifier 152 is connected to the live wire of the household power 18 via the lamp 17. A second terminal T2 of the rectifier 152 is connected to the ground wire of the household power 18. When the base of the second bipolar junction transistor 153 is pulled to logic 1 by the processor 11, the second bipolar junction transistor 153 is turned on, thereby activating the optical coupler 151. Then the rectifier 152 is turned on. Therefore, the household power 18 turns on the lamp 17. To adjust the brightness of the lamp 17, a brightness adjustment key is pressed. The processor 11 may output a pulse-width-modulation (PWM) signal to the switch control 15 in response to the depressed key, therefore adjusting the average value of voltage (and current) fed to the lamp 17.
In use, a user may press an on key, the infrared remote control 12 sends an infrared light accordingly. The infrared receiver 13 receives the infrared light. The processor 11 reads instructions contained in the infrared light and then turns on the second bipolar junction transistor 153. Therefore, the lamp 17 is turned on accordingly. Thus, it is convenient to turn on/off the lamp 17 in daily life.
Referring to
It is to be understood, however, that even though numerous characteristics and advantages of the present embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201010609034.2 | Dec 2010 | CN | national |
