| 摘要 |
PURPOSE:To apply remote control to each device independently by changing a carrier frequency while using the same custom code. CONSTITUTION:The circuit consists of an oscillation circuit 2 to which an oscillator 1 such as ceramic oscillator is mounted externally, a programmable divider 7 frequency-dividing an output of the oscillation circuit and comprising cascade connection of multi-stages of flip-flops, a changeover switch 8 switching selectively the frequency dividing ratio of the programmable divider 7, an encoder 5 using the output frequency of the programmable divider 7 as a carrier frequency and applying coded modulation to a key input data from a key input circuit 4, and an output circuit 6 outputting an output of the encoder 5 to a device subject to remote control. In order to control remotely a device, the changeover switch 8 is switched selectively corresponding to each device to change the frequency dividing ratio of the programmable divider 7 and obtain an output of the corresponding carrier frequency, and it is not required to provide plural oscillators and an exclusive key input switch as a conventional device to decrease the manufacture cost. |
