Fire alarm!

This afternoon a couple of guys from the Mexican restaurant next door came up our stairs and asked how to get to the roof. They said something about a fire and smoke and it being urgent. We pointed them to our fire escape which has a ladder to the roof and then, for some reason, they lost interest and left. We were wondering if, you know, this was actually important or something when the fire engines started racing towards our building. So we looked out and two fire engines with ladders showed up along with 6 other vehicles and a total of about 25 firemen. It was on! The two ladders extended up to the top of the building where some smoke was coming out and a fireman climbed up to take a look. Fortunately, it didn't look too bad as none of the other firemen went up. Within about 15 minutes they started packing up and left. Just another day in downtown San Francisco.

Posted by fungus amungus 8 years ago  |  last reply 5 years ago

Computer Activated Alarm

Hi, I am trying to make a simple alarm system for ill patients, the alarm will be activated through a mouse click on an alarm icon and trigger an alarm connected to the PC. Does anyone have any ideas on how to tackle this problem? Many thanks in advance :)

Posted by RohanQ 6 years ago  |  last reply 6 years ago

Hacking An Alarm Clock

My sister (yes, the one for whom I made earrings) wants me to modify an alarm clock to run a small electronic device when it goes off. Preliminary research has given me two methods:1) A digital clock with a 555 timer circuitIn this setup, a 555 timer circuit is used to translate the signal to an alarm speaker/piezo disk into a relay. When the clock goes off, the relay clicks, and any electrical device that is run through the relay has power.2) An analog clock with a transistor amplifierIn this version, the analog clock seems to just have a straight DC output to the alarm. The transistor is used to amplify the DC to drive the motor of a fire bell.Which of these would be easier to implement? The device I am supposed to use runs off of 3VDC, so I was just going to run the power line through the relay or through the transformer.

Posted by CameronSS 10 years ago  |  last reply 10 years ago

Alarm using RTC.

Hi, I am new to arduino and RTC DS1307. I am trying to create an alarm using RTC and arduino. I have a buzzer that I have connected to arduinio and also I have connected RTC module to it. I am programming the arduino in such a way that whn the timer runs off, it produces a sound from the buzzer. I am trying to use Time.h and TimeAlarms.h libraries. I dnt know how can I make the timer buzz the buzzer.  This is the code I ve done so far.  #include #include "RTClib.h" #include #include ; RTC_DS1307 RTC; void setup () {     Serial.begin(57600);     pinMode(4, OUTPUT); // set a pin for buzzer output     Wire.begin();     RTC.begin();   if (! RTC.isrunning()) {     Serial.println("RTC is NOT running!");     // following line sets the RTC to the date & time this sketch was compiled     RTC.adjust(DateTime(__DATE__, __TIME__));   } } void loop () {       DateTime now =;     Serial.print(now.year(), DEC);     Serial.print('/');     Serial.print(now.month(), DEC);     Serial.print('/');     Serial.print(, DEC);     Serial.print(' ');     Serial.print(now.hour(), DEC);     Serial.print(':');     Serial.print(now.minute(), DEC);     Serial.print(':');     Serial.print(now.second(), DEC);     Serial.println();     Serial.println();        delay(1000);             //Somthing sould come here to make the buzzer buzz     soundBuzzer(); //sounds the buzzer        buzz(4, 2500, 500); // buzz the buzzer on pin 4 at 2500Hz for 1000 milliseconds } // This is the function to make the buzzing void soundBuzzer(){   } //This is for the buzzer. It produces a beep. void buzz(int targetPin, long frequency, long length) {   long delayValue = 1000000/frequency/2; // calculate the delay value between transitions   //// 1 second's worth of microseconds, divided by the frequency, then split in half since   //// there are two phases to each cycle   long numCycles = frequency * length/ 1000; // calculate the number of cycles for proper timing   //// multiply frequency, which is really cycles per second, by the number of seconds to   //// get the total number of cycles to produce for (long i=0; i < numCycles; i++){ // for the calculated length of time...     digitalWrite(targetPin,HIGH); // write the buzzer pin high to push out the diaphram     delayMicroseconds(delayValue); // wait for the calculated delay value     digitalWrite(targetPin,LOW); // write the buzzer pin low to pull back the diaphram     delayMicroseconds(delayValue); // wait againf or the calculated delay value   } } I am really bad at programming so sorry for mistakes. But please I need help.

Posted by Bam Boy 5 years ago  |  last reply 3 years ago

Out of range alarm

I'm working on a project where I need to have a transmitter and a receiver with an alarm, so when they are apart a certain distance the alarm goes off. I need the alarm to be attached with the transmitter not the receiver, where it will be attached to a valuable stuff for example.

Posted by AmmarK22 11 months ago  |  last reply 11 months ago

Alarm Buzzer Driver? Answered

So I have removed a buzzer from an out of date smoke for fun use, but it doesn't work as expected.  I set up a driver circuit with a 555 and some resistors/capacitors.  I don't deal much with IC's or the 555 and haven't really bothered to learn to use them properly, but I took an LED flash circuit and vastly decreased the capacitance, upping the frequency drastically.  I have included an image of the circuit.  The 555 runs on 6 volts, the buzzer runs on 9 (the blue wires).  The volume was ok, but nowhere near expected levels and I wondered if it had to do with the higher than normal frequency.  I attached it to an arduino and ran the tone function from below audible to above it (whole frequency range) and the sound was very quiet, even using an npn transistor and 9 volts right off the battery hitting the buzzer.  As you can see, the buzzer has 3 leads, i only used two, but as with most 3 poll buzzers I assumed one was just for some form of feedback.  Any voltage in any direction across the three produces sound, so should I use all three, and if so how should I do so.  How would you recommend driving this buzzer?

Asked by 4 years ago  |  last reply 4 years ago

Shock Alarm wrist Watch?

Their basically is not a thing like that out their. I want to build a wristwatch that can shock me at a resettable time. I will keep it on when I sleep so It has skin contact. How do I do this? Please help me because I wont wakeup from anything else tryed everything and I hope this will work.

Asked by 9 years ago  |  last reply 7 years ago

How can we make burgler alarms for our own house?

How can we make burgler alarms for our own house?

Asked by subhahar 9 years ago  |  last reply 9 years ago

need to design a low-cost SMS-based alarm with a very long life battery.

Extremely low-cost SMS-based alarm, that will send a message to a number when the alarm is activated. must be small (10x50x40 cm) and have a long life battery and is to be deployed over a wide geographical area, all within GSM reception

Asked by lukassie 7 years ago  |  last reply 7 years ago

how can i get 6 volts out of a 6 volt motion alarm censor?

i have 6 volt dc motion activated alarm. i need help to to find where i must solder wires so that i will get 6 volts out to activate a solanoid.

Asked by waterpower 8 years ago  |  last reply 8 years ago

Is it possible to make a LED blinking circuit with a single transistor?

Asked by 9 years ago  |  last reply 9 years ago

alarm video

Wath the video if you seen the : knex alarm.

Posted by knex gun and grenade maker 7 years ago

Alien door alarm???

Ok, I wanted to make a door alarm, but the resulting "alarm" would be the sound of the alarm on the Nostromos, from the Alien movie. How could I pull this off??? Thanks a ton!! -Sylar

Asked by Sylar521 9 years ago

How To Use the Alarm from an Alarm Clock in Something Else?

I wanted to make an alarm type thingy, ad I want to use the alarm from an alarm clock. I don't know how though, I tried connecting a cell to the wires that were already on the alarm, but it won't work. I think it's one of those piezo-electric crystal thingies. And I know I have to have pressure on it to work. How exactly would I use it?

Posted by Aeshir 11 years ago  |  last reply 11 years ago

Loudness measurement alarm? Answered

Hi guys, I'm looking for a plan to make a very simple plan for a device that can detect the loudness of a sound and sound an alarm if it is beyond a programmable dB value. Best regards, Vuur.

Asked by Vuur 2 years ago  |  last reply 2 years ago

WIFI alert system for an existing hardwired home alarm system?

Is there a device that would connect to my existing home alarm system and alert me via text or call that an alarm has occurred? Thanks.

Asked by ecaj 3 years ago  |  last reply 3 years ago

how to make a Fridge alarm?

Hi All, I want to make a fridge alarm, but i dont know the right configuration or maybe I need to buy a different time delay module?  Please help me Kind regards, Jonathan

Posted by JonathanH243 1 year ago  |  last reply 1 year ago

Will this Latching Laser Alarm circuit work? Answered

Hello everyone ^^ I'm here to ask about this circuit. I've been searching for a laser alarm circuit for a long time which locks itself when the beam is broke and keeps the alarm running unless if I want to press the reset button without the use of a relay. Unluckily, I wasn't able to find that kind of circuit in google... AND IT FELT HORRIBLE!!! =O Ahem ahem! Anyway, I've come up with an idea of combining the latching push ON and OFF circuit and the Laser alarm circuit. Will it work? please reply =(      WILL THIS WORK--

Asked by Charles Mendoza 5 years ago  |  last reply 5 years ago

Wireless activated buzzer/alarm

Can someone help me with this? I need a wireless activated buzzer or alarm. Similar to the cheap wireless doorbells where you push the button on the remote and the bell rings. Release the button, and it stops. But it needs to be a loud sounding buzzer or alarm, fairly high decibels, and did I mention very inexpensive? Also, the buzzer/alarm part needs to be as small as possible. I appreciate all your help!

Posted by wolfsmane 8 years ago  |  last reply 6 years ago

How can I get a loud alarm?

Ok so I need an alarm for my project, a very loud alarm. . . And I can't seem to get these dumb buzzer to output a decent sound. I have a lipo checker that uses these type of buzzers  and they are ear shattering. I tried putting the regular buzzers and the were no where near as loud. Also if I want to use the tone function on the arduino, how do i make the buzzer louder?

Posted by HavocRC 3 years ago  |  last reply 3 years ago

Alarm Clock?

Is there a relatively easy way to make an alarm clock?

Posted by kylechu 11 years ago

Laser alarm circuit

I am searching for a circuit which can drive a siren circuit like this and can be activated by a laser pointer.I have tried a lot of these circuits but all had the same problem:The siren sounds only for a few seconds(As long as the interruption of the laser beam...) Thank you in advance!

Posted by pizza1993 7 years ago  |  last reply 7 years ago

Distance Alarm?

Hello, I am interested in seeing if I can create some sort of alarm for my 10 year old son.  He has autism and I'm looking for something kind of like a house arrest ankle bracelet BUT i don't want it to track where he is. (Not at this point anyway).   For now i just want to see if I can make a distance alarm.  I would strap a bracelet to his ankle and I could carry the alarm unit in my pocket to If he got more than 100 feet from my device I would hear an alarm.  He has an issue with wondering away and the electronic monitoring companies want to charge hundreds of dollars to put a house arrest type monitor on him.  If i could make  something that would warn me when he starts to wonder that would be amazing! Can anyone point me in the correct direction? Thanks

Posted by author-unnknown 4 years ago  |  last reply 4 years ago

Any easy way to hack a projection alarm cock (led to ceiling) so that I can turn the projector on/off with a remote?

I assume the clock has the ability to turn the projector on/off.  How hard would it be to hack in a remote control for this feature?  (they dont seem to sell anything like this.)

Asked by 9zpvwz 7 years ago  |  last reply 6 years ago

laser beam alarm using NE555 ?? circuit question

Hi all my project idea : using laser beam and LDR to make a security alarm circuit , when the beam is cut , it will trigger the NE55 circuit for certain time (5 seconds only ) there is a lot of 555 dark-activated circuits on the WWW,  i know , but all of them are like on/off switch what i need is one with adjustable delayed time can you help me ??  thanks in advance

Asked by lu2a 7 years ago  |  last reply 7 years ago

Car Alarm

I just had an idea.... Someone needs to make a car alarm app for smart phones. It can use the microphone to listen for breaking glass, the speakerphone for playing pre-recorded messages (step away from the vehicle, the police have been called), the camera can sense movement inside the vehicle and the GPS can sense (and report) movement of the vehicle. All of this information can be sent in real time to the other phone that you carry with you. Installation is as easy as turning it on and tossing it in the seat! Compatible with any car! Battery backup! :)

Posted by AsianSpanker 7 years ago  |  last reply 7 years ago

How can I make a Burglar alarm using ultrasonic sensor with a microcontroller Zilog Z8? Answered

We were asked to construct  a burglar alarm using ultrasonic sensor with a micro controller Zilog Z8. It's our requirement for the Final term this semester. We also have difficulties in our documentation because it is in thesis format. I know that somebody can help us from Instructables. We definitely need documents so we can have ideas to be included in our documentation. Thank you so much. God bless. ^^,

Asked by AljonSalvatore 5 years ago  |  last reply 5 years ago

6v-9v trip wire for trail?

Layout of trip wires for 3 trail alarm with lights. About 250' range from panel no noise just lights on trip to panel.     Thanks Alan

Asked by picker2 8 years ago  |  last reply 8 years ago

Short range battery operated 2 part (door alarm type) distance sensor.

Hello all! I'm looking to design a range compact distance sensor that will sense 1-4 ft increments. If necessary i could modify a door alarm. id like to fab one or multiple if need be to sense the distances noted. I could utilize a buzzer or some way to record a voice that would alert to said distance. The battery voltage max is 4.2v dc and if it could be rechargeable that would be a plus. Any help on this would be greatly appreciated. Thanks!

Posted by Automan350 1 year ago  |  last reply 1 year ago

An Alarm Clock Idea - No Lights, No Sound

I'm a pretty deep sleeper, and I don't wake up very fast in the mornings, which is bad since I ride the school bus to school. I set my alarm clock, with a high volume, but it still doesn't wake me very good. I've thought of trying to make an alarm that flashes a strobe light, something like a deaf person might use, but didn't think it would work very good. So, my idea now is to think of a way to make an alarm clock that gives pulsating shocks when it goes off. I have absolutely (well, 99%) no idea how to connect it up, nor how to produce the shocks. I'm thinking a shock with high voltage, but low current, like static electricity. I figure that should wake me. Do y'all have any ideas, or better suggestions? Also, do you think that the shocks (if usable) would cause any dangerous effects on my health? Thanks!

Posted by Bran 11 years ago  |  last reply 8 years ago

How to build a max distance alarm

I've been searching for an instructable that does that but couldn't find it. The basic idea is to put a small as possible tag to something(unpowered if possible) and have another small thing that can fit in your pocket. If the tag goes more than, say, 4,5 or 6 meters away your pocket box would warn you. I think its a great idea to protect from thieves but no idea on how could I build a device like that. Thanks

Posted by Saladino 10 years ago  |  last reply 10 years ago

Is there a way to have an electronic key on my cats collar so everytime she goes in my room a buzzer goes off ??

I was wondering if you could make an electronic key or something like that so when she crosses or enters the area a buzzer or alarm goes off so she runs away.

Asked by jules15 9 years ago  |  last reply 9 years ago

Just to make sure! 30A to charge battery?

Hey! I have an old home alarm system which is broken beyond repair. I just wanted to make sure if it is OK to charge the 12v battery at 2.1 or2.4 Ah with an ATX PSU at 30A? Will the battry just take 2A from it? If not I have the transformer that came with the Alarm, would that be safe to charge with? It's 12v BTW. Thanks. Never can be too careful. Also, I'm using it on a scanner light tube, this will be fine, yes? I have the starter, it is not a problem. It's weird though, when it is lit, you can pull out the ground on the light tube, not the starter and ut still stays lit. Weird. Thanks in advance!

Posted by Josho 11 years ago  |  last reply 11 years ago

DC power drop alarm Answered

I need a very simple way to see if power is ever lost to load.  I am trying to run a long term test of at least 60 days.  I have a UPS that is powering a load and I need to be able to determine if the 12 - 15 V dc that the UPS is providing is ever lost. The UPS has a battery that will supply power if the AC input is lost.  The solution can be very simple and I really don't want the load to be reconnected if the current going to the load is ever lost. I need to know if the load is ever not powered, even for a brief instant.  I was hoping there might be some type of switch that would open if the current stopped flowing through it.  Sorry for the simplicity but I know very little about electronics.  Thanks for any help or advice.

Asked by brentatespicorpdotcom 2 years ago  |  last reply 2 years ago

How do I wire a three-terminal piezo buzzer to make it sound?

I salvaged a piezo sounder from a CO detector.  The sounder (EFM-290ED rated at 9V) has 3 pins rather than the two I am more familiar with.  The pins are labled G, F, and M.  I have tired applying 9V across all combinations of the pins but haven't had any luck maiking it sound.

Asked by jrosserb 5 years ago  |  last reply 3 years ago

Wiring, DSC PC1832 security system at home, how?

Http:// Hey, hope somebody can help me to getting this thing work properly, im not sure how to connect the keypad, smoke and move detectors... i got 3 zones to move detectors(means that in one floor i got all detectors joint on one wire, and now, where on that board i put red and black(+12 and -) yellow and blue(NO and C) That picture is not my taken, found it on inthernet. Thanks for any help:) Sorry for my bad english.

Posted by blackrock112 8 years ago  |  last reply 8 years ago

how can i make a homemade fire alarm? Answered

I wan2 make a homemade fire alarm dut dont know to.

Asked by knex gun and grenade maker 7 years ago  |  last reply 6 years ago

How to hack a smoke detector's alarm to change the sound?

I want to change the alarm sound.

Asked by sheen16 5 years ago  |  last reply 5 years ago

Shock alarm clock

Hi,  I want to build a Alarm that will shock you when the clock hits a certain time i am new to this could someone help me out ?!

Posted by josephwilmott2 1 year ago  |  last reply 1 year ago

panic alarm data?

 i request to get data about panic alarm.

Asked by nelson ndegwa 3 years ago  |  last reply 3 years ago

Plasma alarm clock?

I am thinking it might be fun to hack the speaker output on a digital alarm clock to somekind of plasma device that uses a flyback transformer. Something along the lines of a lightning alarm clock that was released a few years back.

Posted by argos090 6 years ago  |  last reply 6 years ago

RTC Alarm using serial monitor

Hi, I have an arduino UNO and RTC DS1307. I want to make an alarm that just displays on the serial monitor of arduino UNO. I can make the RTC show the right time on the serial monitor, however I want an alarm to go off on the serial monitor. Also, is there any way that I can change the alarm time on the serial monitor? Like I can type from my keyboard and the time changes? One more question, How can I make arduino do multitasks using RTC. Like when the alarm goes off, it can run a small DC motor and also a Pizep Buzzer.  Please help me with this, as I desperately need a help :((

Posted by Bam Boy 5 years ago  |  last reply 5 years ago

How to wire a light to an alarm clock?

Where I work during the summer I consistently have to switch between the day and night shifts. This happens every month or so and during the first week of transition I have a rather hard time waking up especially from transition from day to night shifts where I have to sleep during the day. Thus it is dark when I am supposed to wake up. Although I have not been late yet there have been quite a few "near-misses". Anyway I want to know if anyone can help me wire a light to my alarm clock to help this. My alarm clock alternates between a one second-ish noise to an equal length silence and repeats. I would like it to turn on and off in the same fashion as the alarm clock makes noise. I do not have much electrical know how, but I am adequate at soldering both wires and on boards. I have tested the output of the wires leading to the speakers and they do not have enough power to turn on the bulb. It would also be nice if can be done on a wallet friendly cost, college is eating up most of my money. Any help would be appreciated and thanks in advance!

Asked by swingline 8 years ago  |  last reply 8 years ago

how can i make a fire alarm system? Answered

I want to make a fire alarm system for a low cost.

Asked by knex gun and grenade maker 7 years ago  |  last reply 6 years ago

Laser Alarm System

Hello guys, I need some help building a circuit. I'm new to electronics, so go easy with me. Is there a way to build and laser alarm circuit but instead of the alarm going on just when the beam is broken the alarm stays on until I turn it off? Circuits like Kipkay's only go off when the beam is broken. How can I make the alarm stay on once the beam is broken? Thanks

Posted by HavocRC 6 years ago  |  last reply 6 years ago



Posted by kwabena 10 years ago  |  last reply 10 years ago

I am looking for a device that will listen for a smoke alarm to go off.

All it needs to do is have an indicator that trips when the alarm goes off.  I replace smoke detectors that give faulse alarms but I am never there to hear them.  There are two sounds they make, one is a chirp (low Battery) and a full alarm very loud.?

Asked by drvolt 6 years ago  |  last reply 6 years ago

how to make light alarm cencored?

Asked by 9 years ago  |  last reply 9 years ago