In comparison to the conventional electric whistle, the oscillation frequency of the audio control signal in accordance with the present invention is simply determined by the tone-set resistor R 1 without a capacitor. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed. The control IC 40 generates an oscillation signal and sends the oscillation signal to the transistor Q 1 via the first pin to activate the transistor Q 1. With respect to the electric whistle of the present invention, the sound IC has sound tracks installed as original equipment. The selection pins K 1-K 4 respectively correspond to the sound tracks and respectively connect to switches S 1-S 4.

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The oscillation frequency of the audio control signal is determined by the single tone-set resistor without a capacitor.Download PDF Info Publication number US8760272B2 US8760272B2 US13/551,759 US201213551759A US8760272B2 US 8760272 B2 US8760272 B2 US 8760272B2 US 201213551759 A US201213551759 A US 201213551759A US 8760272 B2 US8760272 B2 US 8760272B2 Authority US United States Prior art keywords pin electric whistle control terminal electric whistle Prior art date 2012-07-18 Legal status (The legal status is an assumption and is not a legal conclusion.

WHISTLE | Fox 40 International ELECTRONIC WHISTLE | Fox 40 International

The oscillation unit 32 determines which one of the selection pins K 1-K 4 is grounded and generates an audio control signal based on the tone-set resistor R 1 and the corresponding sound track. Therefore, the electric whistle of the present invention is compact and can be manufactured at low cost. We provide you with the absolute best protection and ongoing support in the security industry today.

and 2, a first embodiment of the present invention comprises a power circuit 10, an inductor L, an electric switch Q 1, a buzzer 20, a tone-set resistor R 1 and a sound IC 30.

Xflyee Electronic Whistle with USB Charging, 3 Tone

The capacitor C 1 is adapted to filter unstable noises to gain the stability of the electric whistle of the present invention.The electric whistle is more sanitary than a conventional whistle which is put into the mouth because the electric whistle can buzz loudly without being blown. com is the complete industry guide and your ultimate sourcing platform for security products, including but not limited to cheap electronic whistle, discount promotional items, promotional gift. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed. For example, when the selection pin K 4 is grounded, the oscillation unit 32 generates the audio control signal of the whistle ringing.