TV Remote Launch circuit
Industrial remote control requirements of precision, sensitivity, signal consistency, real-time, anti-jamming, remote control distance, waterproof and dustproof, high and low temperature resistance, acid and other technical parameters, than the civilian remote control, industrial remote control To adapt to a variety of harsh environments; these are civilian remote control can not replace the industrial remote control reasons.
2.4GHz band radio (RF). More than the infrared remote control is not just physical layer media. The change of the physical layer, the shape of the remote controller, the type of the button, the type of the control object, and the like may change.
For example, Japan's first use of RF as a TV remote control of the Sony company put the remote control from the traditional bar to a flat rectangle. Infrared remote control is mostly slender shape, because the infrared need to point to the direction of the TV. The RF remote control is the use of a relatively slow communication of radio waves, basically do not need to point to the TV.
Infrared remote control of the launch circuit is the use of infrared light emitting diode to send modulated infrared light; infrared receiver circuit by the infrared receiver diode, transistor or silicon photovoltaic cells, they will be infrared emitter infrared light transmission into the corresponding electrical signal, Amplifier.
The transmitter is usually composed of instruction keys (or operating rod), instruction coding system, modulation circuit, drive circuit, transmission circuit and other parts. When the command key is pressed or the joystick is pushed, the instruction code circuit generates the required instruction code signal, instructs the coded signal to modulate the carrier, and then carries out the power amplification by the driving circuit and emits the modulated instruction code by the transmitting circuit signal.
The receiving circuit is generally composed of a receiving circuit, an amplifying circuit, a modulating circuit, an instruction decoding circuit, a driving circuit and an executing circuit (mechanism). The receiving circuit receives the modulated coded command signal sent by the transmitter and amplifies the demodulation circuit, and demodulates the demodulated circuit to demodulate the modulated instruction code signal, that is, to the encoded signal. The instruction decoder decodes the encoded instruction signal, and finally the drive circuit drives the execution circuit to implement the operation control (mechanism) of the various instructions.
Color TV in the use of the following are usually the following aspects to control the preselection program, select the station, volume, brightness, color, contrast, boot, shutdown. For non-remote control TV, people in the viewing, you must pass the TV panel buttons, knobs, to control the above to meet the requirements. The remote control color TV can be held by the user's remote control command transmitter (remote control) to the TV for remote operation control. At present, almost all of the remote control of color TV is using infrared transmission control signal. Infrared is an invisible light, which is issued by the user's hand held by the remote control. Therefore, the composition of infrared remote control color TV and ordinary color TV compared to just add a set of remote control system, the block diagram shown in Figure 3-1-1. Remote control system is usually composed of infrared remote control receiver, infrared remote control transmitter, microprocessor (referred to as CPU), program electric rewritable memory, interface circuit and other parts. According to practical needs, remote control color TV control methods are both local control and remote control. Local control is the user press the button on the panel to the microprocessor command, and then issued a series of operating instructions through the microprocessor, the final output control voltage to achieve the control of the color TV. Remote control is through the remote control to issue control commands to achieve the control of color TV. There are many control buttons on the remote control, each of which represents a control function. When a button is pressed, the encoder in the transmitter outputs a set of control codes (binary code) that are modulated at a high frequency of about 450 kHz and are amplified to drive the infrared light emitting diode in the form of infrared light Radiation out, mounted on the TV panel of the semiconductor infrared photoelectric conversion diode by the transmitter issued by the basic principle of infrared optical radiation.