发明名称 |
Signal switching circuit for multiple sound siren system |
摘要 |
A circuit for switching between two signals of different frequency, such as "wail" and "yelp" of an electronic siren, by switching between different capacitive values in a multivibrator circuit. A monostable switch couples a reference level voltage to an integrated flip-flop circuit. The integrated circuit receives a reference level pulse when the monostable switch is closed and supplies a switching voltage to a transistor circuit. The transistor circuit places capacitances in parallel to change the time constant of the multivibrator circuit and also to change the characteristics of wave-shaping circuitry coupled to the multivibrator circuit. A reference level circuit accepts either of two voltage levels and provides a reference level voltage.
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申请公布号 |
US4054869(A) |
申请公布日期 |
1977.10.18 |
申请号 |
US19750629016 |
申请日期 |
1975.11.05 |
申请人 |
CARSON MANUFACTURING COMPANY |
发明人 |
SMITH, GERALD D.;WITTE, SAMMIE S. |
分类号 |
G08B3/10;G10H5/00;(IPC1-7):G08B3/00 |
主分类号 |
G08B3/10 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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