Maker Pro
Maker Pro

How to turn Smoke alarm into Ultrasonic Dog Repeller

ArtJ

Sep 26, 2018
4
Joined
Sep 26, 2018
Messages
4
I am pretty new to all that stuff.
So far have experimented with 555 at 10-25kHz, but the dB is too low. Even at 10kHz the output power is pretty low (measured by my Samsung app, OScope at distance 2-4 cm it's just a few dB). I am using a piezo transducer from an old sound system).

My question : Is it possible to turn an old smoke alarm into a Ultrasonic Dog Replant?
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,510
Joined
Jan 21, 2010
Messages
25,510
Was the dog planted previously? My gardening experience tells me that you should probably use a bigger pot when you replant it.

Perhaps you mean repellant?

Do you know what repels dogs? I don't. When one of our smoke alarms goes off it annoys the heck out of me, but the dogs just ignore it.
 

ArtJ

Sep 26, 2018
4
Joined
Sep 26, 2018
Messages
4
Was the dog planted previously? My gardening experience tells me that you should probably use a bigger pot when you replant it.

Perhaps you mean repellent?

Do you know what repels dogs? I don't. When one of our smoke alarms goes off it annoys the heck out of me, but the dogs just ignore it.



Apologizes. Not Replant. it is REPELANT, Dog Silencer
 

ArtJ

Sep 26, 2018
4
Joined
Sep 26, 2018
Messages
4
Any way that I can edit the title? From Replant. to REPELANT, Dog Silencer
 

ChosunOne

Jun 20, 2010
480
Joined
Jun 20, 2010
Messages
480
I assume you mean an Ultrasonic Dog Repellent?

10-25kHz isn't really ultrasonic--most adult humans hear up to 20 KHz, and most kids well into their teens hear up to 25 kHz ( and many of them beyond).

I seriously doubt that that an old smoke alarm sounder can be modulated to sound in the ultrasonic range. In the USA, the high-pitched piezo sounders (as opposed to the older raucous buzzers) sound a lot like a Mallory SC628 Sonalert piezo sounder that operates at 2.9 kHz. Given that (as I understand it), that frequency is governed by a crystal integral to the sounder, I doubt it can be boosted up into the U/S range.

EDIT: Sorry, I didn't see your corrective post before I posted.
And an ultrasonic dog repellent is likely not to be a dog silencer--I suspect that dogs that have to endure it (i.e., can't escape it) might be noisy in their protests.
 

ArtJ

Sep 26, 2018
4
Joined
Sep 26, 2018
Messages
4
Hm, it doesn't sound promising.
Any chance of replacing the whole sounder with a small piezo (80 dB) I guess the impedance will be pretty similar so the amp wont struggle with the capacitive load?
Then uplifting the output frequency to 25 kHz ( the best freq to silence dogs)?
 

Bluejets

Oct 5, 2014
6,901
Joined
Oct 5, 2014
Messages
6,901
Hm, it doesn't sound promising.
Any chance of replacing the whole sounder with a small piezo (80 dB) I guess the impedance will be pretty similar so the amp wont struggle with the capacitive load?
Then uplifting the output frequency to 25 kHz ( the best freq to silence dogs)?

I don't know........our cat took one look and disappeared for 2 days the last time my burglar alarm went off(same sound) ...last I saw him he was about 300m away taking a look back to see what the hell was that//

Guess I should add in fairness, he was in a deep sleep in the middle of the day at the time :)

Then again, dogs seem to have attitude and you're likely that the response will be he don't give a fug.

I have seen where old smokies are hacked ( fairly simple) for use as water level alarms.
 

Audioguru

Sep 24, 2016
3,656
Joined
Sep 24, 2016
Messages
3,656
A piezo transducer is made to produce audible beeps, not ultrasonics.
 
Top