Home  |  Circuit diagrams  |  Electronics projects  |  Store  |  Links  |  Contact  |  Privacy policy  |  Sitemap

..::::..





Yongnuo Flashes

Whistle Responder

Whistle Responder

Device purpose:

Some 15 years ago it was common to see small key-holders emitting an intermittent beep for a couple of seconds after its owner whistled. These devices contained a special purpose IC and therefore were not suited to home construction. The present circuit is designed around a general purpose hex-inverter CMos IC and, using miniature components and button clock-type batteries can be enclosed in a matchbox. It is primarily a gadget, but everyone will be able to find suitable applications.

Circuit operation:

This device beeps intermittently for approx. two seconds when a person in a range of about 10 meters emits a whistle. The first two inverters contained in IC1 are used as audio amplifiers. IC1A amplifies consistently the signal picked-up by the small electret-microphone and IC1B acts as a band-pass filter, its frequency being centered at about 1.8KHz. The filter is required in order to select a specific frequency, the whistle's one, stopping other frequencies that would cause undesired beeper's operation. IC1C is wired as a Schmitt trigger, squaring the incoming audio signal. IC1D is a 2 second (approx.) monostable driving the astable formed by IC1E & IC1F. This oscillator generates a 3 to 5Hz square wave feeding Q1 and BZ1, thus providing intermittent beeper's operation.

Notes:

Power supply range: 2.6 to 3.6 Volts. Standing current: 150

..:: Important ::..

Read disclamer, please!

 

Circuit diagrams home  |  Circuit diagrams  |  Electronics projects  |  Store  |  Links  |  Privacy policy  |  Contact


Cialis 5 mg senza ricetta Effetti collaterali del Cialis 5 mg Ordina Cialis 20mg Consegna a domicilio di Cialis originale in Svizzera Acquista Viagra in Svizzera senza prescrizione Cialis 10mg senza ricetta Dove comprare Viagra in farmacia online Sconto Cialis 5mg Dónde adquirir Reduslim Spedra Avanafil in vendita online Acquista Viagra in Svizzera senza prescrizione Dónde comprar Cialis Comprar Viagra Contrareembolso Descuento Cialis 5 mg Comprar viagra original Efectos secundarios de Cialis 5 mg Reduslim resultados Remedios para la Disfuncion Erectil Cilis vs Viagra Aviator игра на деньги Acquisto Cialis 5 mg online Cialis 5 mg effetti collaterali Comprare Cialis 20mg a buon prezzo Consegna a domicilio di Cialis originale in Svizzera Acquisto online di Viagra senza ricetta in Svizzera Cialis 10mg Acquistare Viagra in farmacia online Costo del Cialis 5mg Reduslim opiniones Comprare Spedra Avanafil senza ricetta online Dove comprare il Viagra in Svizzera Comprar Cialis barato precio Viagra genérico Descuento Cialis 5 mg Viagra sin receta Cialis 5 mg efectos secundarios severos Reduslim pérdida de peso Problemas de erección tadalafilo en venta avanafil prezzo cialis 20 mg prezzo cialis effetti benefici cialis 10 mg Reduslim Kaufen pulse x coin price avanafil prezzo buy cialis or generic tadalafil