Alarm circuit using 555 timer

388

07:47:26

Just replace the push button switch with a vibration/motion or sound sensor and LED with a relay to the horn.

published 9 years ago

2ctiby

9 years ago

It's basically very nice, but it doesn't work in real time. Can you get it to work with the oscilloscope time set to 1s ?

peterian12

9 years ago

@2ctiby, you mean the blinking of LED? If thats what you mean, you can change the resistor and capacitor on the astable circuit.

2ctiby

9 years ago

No, I mean that your schematic shows an oscilloscope timescale reading of 1ms. That looks good on EC here, but in reality the flashing rate would need to be as per 1s oscilloscope reading, not 1ms reading. ..... slide your finger across the oscilloscope from left to right until the timescale there reads 1s....that will show how many flashes we get per second as viewable if real life. You will notice when you do that how your schematic no longer works......play with it then let me know if you need help.

peterian12

9 years ago

I see... haha... i didn't notice that.. i'll just update this later and play with it... i've used this circuit in my motorcycle thou the resistors and caps are different than this circuit... :)

2ctiby

9 years ago

http://everycircuit.com/circuit/6364470435119104

peterian12

9 years ago

Great circuit! Thanks for giving samples and additional knowledge. Really appreciated. I also updated mine... feel free to suggest... thanks

2ctiby

9 years ago

Your'e welcome....I just hope my effort isn't too far out...I haven't built it....I decided on mosfet due to low current for the transistor base (mosfets rely on voltage there), but I didn't work at it a lot and I think perhaps some changes might be necessary ... just playing around here really....and I see that your transistor version has been well adjusted already....great!

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