by
3lectrix
Published on 17th June 2011 04:35 PM
Number of Views: 7386
Most of the power supply failure indicator circuits need a separate power supply for themselves. But the alarm circuit presented
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by
3lectrix
Published on 15th June 2011 11:33 PM
Number of Views: 7265
This circuit will produce an audible alarm when the water level reaches a preset level.The circuit can be powered of a 3V battery and is very handy to use.
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by
ElectroMaster
Published on 5th January 2010 06:17 AM
Number of Views: 9567
The circuit uses a 555 timer wired as an astable oscillator and powered by the emitter current of the BC109C. Under dry conditions, the transistor will have no bias current and be fully off. However as the probes get wet the transistor will conduct and sounding the alarm.
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by
ElectroMaster
Published on 5th January 2010 05:53 AM
Number of Views: 7200
This circuit features automatic Exit and Entry delays and a timed Bell Cut-off. It has provision for both normally-closed and normally-open contacts,
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by
cyb0rg777
Published on 5th January 2010 12:12 AM
Number of Views: 5797
I built this circuit recently and decided to do a rough schematic and post it here.It is a car alarm.You need to mount the
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by
ElectroMaster
Published on 4th January 2010 03:01 AM
Number of Views: 4881
A few months ago, I decided to build a compact, yet effective alarm. My demands were:- simple construction, reliable operation, very small power consumption, and, most
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by
ElectroMaster
Published on 4th January 2010 03:01 AM
Number of Views: 5789
Each zone uses a normally closed contact. These can be micro switches or standard alarm contacts (usually reed switches). Zone 1 is
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