| 摘要 |
PURPOSE:To automatically use only the information transmitted in a frequency carrier not affected with noise at a receiver, by sequentially transmitting the same information with different frequency carriers. CONSTITUTION:When an operation switch SW2 is momentarily turned on, a microcomputer (MC)1 outputs a code signal in pulse form to a data terminal 5 for a constant time. Simultaneously, the 1st output terminal 6 is kept to a high level and the 2nd output terminal 7 is to a low level at the T1 period. As a result, an AND gate 8 turns on during high level period of a pulse output from a data terminal 5 at the T1 to turn on a driving transistor 12 of the 1st oscillating circuit 10. Then, an oscillation section mainly consisting of a resonance circuit 13 having a resonance frequency in f1 and an oscillating transistor 14 outputs a intermittent signal in frequency f1 in response to the pulse signal. On the other hand, the 2nd oscillation circuit 11 outputs an intermittent signal in frequency f2 at T3. The output of the 1st and 2nd oscillation circuits 10 and 11 is applied to an output section 17 via an adder 16, and output is given from the output section 17. |
