| 摘要 |
PROBLEM TO BE SOLVED: To provide a telephone line busy light display circuit, with which the indication of light showing telephone line busy is not turned on by an incoming bell signal. SOLUTION: A first electronic switch 1 is turned on in response to the generation of the incoming bell signal. At such a time, a second electronic switch 2 is kept off. Thus, a light emitting diode(LED) connected to the second electronic switch 2 is kept in the OFF state. Therefore, while an incoming bell is sounded, the LED is not turned on at all.
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