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This Dummy Alarm project makes an LED flash briefly once every 5 seconds to imitate the indicator light of a real alarm. The circuit is designed to use very little current to prolong battery life so that it can be left on permanently. An on/off switch is not included, but could be added if you wish.
The 7555 timer IC used is a low power version of the standard 555 timer. A 'superbright' red LED is used because this provides a bright flash with a low current. The LED is off for most of the time so the average total current for the circuit is less than 0.2mA. With this very low current a set of 3 alkaline AA cells should last for several months, maybe as long as a year.
The circuit will work with a standard 555 timer IC (such as the popular NE555) but this will increase the average current to about 2mA and the battery life will be much shorter. You can use a greater supply voltage (15V maximum) for this circuit but the 1k resistor for the LED should be increased to keep the LED current low at about 3mA. For example to use a 9V PP3 battery change the 1k resistor to 3k3. Note that AA cells will last longer than a 9V PP3 battery.
This project uses a 555 astable circuit.
What else can I help you with?
How does power supply failure alarm circuit works?
Power supplies don't fail. Idiot.
What is the opposite of irrigation?
your mom that's what it is dummy
Do loops for dummies?
do <some statement here, dummy> while (<a condition here, dummy>); It will repeat the statement, and after every repetition checks the condition: if false, leaves to loop.
What is thyristors?
A thyristor is a part of a alarm circuit you use it so the alarm stays on
What is the procedure of rain alarm?
it s a way ejfwefdm kkf,
Your Ford Escape ignition was disabled by the alarm system. How do you reset it?
i dont know dummy:)LOL
Why ic7555 timer is used in dummy alarm project?
cause it is cheap and easily available through the electronic components stores
How do alarm clocks work?
An internet alarm clock works the same as a normal alarm clock just it is based on the internet. You enter the time you wish the alarm to go off and as long as your computer is turned on and connected at the time then it will sound the alarm.
Why does us human needs a computer to do your office works?
Hay buddies, my computer do nothing, unless i do something with it. The Computer is simply a dummy. But the worl's most beautiful dummy.
Set athletic works watch alarm?
You can't
Athletic Works watch?
How Do I Turn off Alarm on Athletic Works Watch ATHM4885
2004 Chevy Tahoe what does it mean when security light goes on when you engage alarm?
It means it works Security alarm
How do you reset the password of a home alarm system?
There are a few different kinds of home alarm systems available today. Each one of these alarm systems works differently.
Do i need to register my fire alarm?
no i dont it works fine ok..............................
Is a swimmer a fish?
no dummy no dummy no dummy
Can you make a dummy ground for the power window switch in the tailgate of a 89 ford bronco 5.0L?
If it works -- go for it
Where can you buy the quality security systems like dummy cameras and fire alarm systems?
Hi,There are plenty of players in the market.. If you're planning to buy security systems for your shop or office dummy cameras would be enough as it's not only cheap but also keep people wary of being under scan.. Fire Alarm systems would be very helpful in case of emergency.. Try this link:http://www.security2020.com/
