Category Archives: Security

Delayed Car Door Alarm

Posted on November 7, 2011 by Rust

Opening car’s door is very simple activity, and off course it’s just a daily activity which require no special skill. Almost nothing can go wrong, but forgetting to close the door when we doing or thinking on many tasks is … Continue reading →

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Burglar Alarm Works for Both N.O and N.C Contacts

Posted on March 31, 2011 by Rend

Unlike other alarm circuit that provide normally-open only or normally-closed only configuration, this alarm circuit work for both configurations. The mechanism of this alarm circuit is very simple, that the output will be active (Q1 transistor will be conducting) if … Continue reading →

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Dual Tone Single IC Siren

Posted on December 24, 2009 by Adam
Dual Tone Single IC Siren

This circuit is a double tone Police sound and Single tone old ambulance sound. This circuit is usually installed on a on battery powered cars, motorcycles, and bicycles for fun kid not only that, this circuit also used in  models … Continue reading →

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