Suggestions for a 24 hr. motion sensor to activate a siren alarm .. #2

Thread Starter

Tim@kzn

Joined Nov 23, 2023
2
This is what I need:
  1. Suggestions for the purchase of a motion sensor.
  2. 110 volt motion sensor with 24 hour detection that will activate an external siren upon detection of motion in the room
  3. It will be mounted inside a 40 x 60 workshop
  4. I would like to wire it through a light switch for deactivation when I am entering the building & then switch it on to activate upon leaving.
  5. I have one currently installed but it has an 80 second test/activation mode which sets off the siren for 80 seconds upon switching it on. When I leave and switch the detector on I don't want to listen to 80 seconds of a loud siren before it self silences and resets to detection mode.
  6. I need a simple day and night motion sensor that will activate a siren when powered up & detecting motion.
  7. Thank you for your suggestions.
Hi Chitreno

Please may I ask you advise.
I tried using your same method with a infrared motion sensor 220v and a siren that's also AC220v. Problem I am having is that thr siren keep going off and on continuously. I have tried the sensor on a light globe and it works perfect but on the siren is just keeps going off without any movement in front of the sensor. Please can you assist me please.


Moderation. Created a new thread.
Link to Old Thread.
https://forum.allaboutcircuits.com/...to-activate-a-siren-alarm.172366/post-1545005
 
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Thread Starter

Tim@kzn

Joined Nov 23, 2023
2
Hi Chitreno

Please may I ask you advise.
I tried using your same method with a infrared motion sensor 220v and a siren that's also AC220v. Problem I am having is that thr siren keep going off and on continuously. I have tried the sensor on a light globe and it works perfect but on the siren is just keeps going off without any movement in front of the sensor. Please can you assist me please.

BTW: Chitreno has not been on AAC for 3 years.
 
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Ya’akov

Joined Jan 27, 2019
8,973
Welcome to AAC.

Just a SWAG*, but try measuring the voltage form the motion detector for a while. Maybe there is a fluctuating voltage that is not high enough to light the lamp but is to sound the siren.

Just connect a meter across the output and watch. You can also do the same with each device attached. The purpose is to gather some information about what is actually going on so a solution can be found.

*SWAG is Scientific Wild Assed Guess. It is distinct from a WAG in that it is a surmise based on experience while a WAG is just words entered in a lottery for the correct answer.
 

Tonyr1084

Joined Sep 24, 2015
7,777
Some switching motion detectors use electronics to do the switching. MY experience has been that putting LED's on a Motion Sensor Switch (MSS) has been that sometimes - not always - but sometimes the MSS does not have enough load on it to switch the lights off. I've had LED's that would flicker and be (estimating) 70% brightness, not full brightness. The solution has been to add into the circuit one incandescent type light bulb.

Now, those are light bulbs. I don't know what a motor such as a siren might draw. And at that I'm guessing you're talking about a motor driven siren. IF you have an electronic siren then maybe it doesn't draw enough current, same as the LED's in my case. These are just guesses, but I've used MSS's in several places. The laundry room has been my most problematic room with lights and LED's. However, the lights in my lab, also on an MSS, switch on and off with no additional issues.

Electronic switches, depending on their design, don't like loads they were not designed to handle. In my bedroom I have a ceiling fan with four lamps. The fan/lights are connected to a dimming switch. With all four LED's in the sockets I get almost no dimming at all. At best it might dim by 20%. But remove just one LED lamp and install one incandescent type and I get the full range of dimming from 100% down to (maybe) 30% brightness.

Here's a video of my bedroom lights:
 

MisterBill2

Joined Jan 23, 2018
17,800
Hi Chitreno

Please may I ask you advise.
I tried using your same method with a infrared motion sensor 220v and a siren that's also AC220v. Problem I am having is that thr siren keep going off and on continuously. I have tried the sensor on a light globe and it works perfect but on the siren is just keeps going off without any movement in front of the sensor. Please can you assist me please.

BTW: Chitreno has not been on AAC for 3 years.
I recently had a similar but different experience with a motion sensor that I installed to control both a nearby light and a remotely located light. The sensor functioned correctly when controlling both an incandescent light and a small 120 volt coil relay, BUT when the light bulb failed then the relay would not operate either.
SO my suggestion is to have your motion sensor switch on both an incandescent light, 25 or 60 watts, or some similar wattage, and also switch on a relay with a 220 volt coil and contacts suitable to control the siren. The siren power feed should be separate from the motion sensor power feed. That is to provide a bit of isolation in case the siren generates noise that feeds back to the motion sensor.
 

MisterBill2

Joined Jan 23, 2018
17,800
Bill: Do you not read other posts? Same thing with the thread on the horn rebuild.
YES, I was aware that it was already casually suggested. And quite ignored. So I verified the statement relating a duplicate, verified, personal experience.
Aside from that, YES, I do tend to repeat when ignored.
 

Tonyr1084

Joined Sep 24, 2015
7,777
I've done that. But I've also included a quote from the first mention. Then I add "I second this thought" or something like that. I don't try to take credit for an idea someone else has already espoused. That's not cool.

Sorry for off topic. Will cease and desist.
 
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