Simple cat deterrent alarm help please.

[skyboy]

It is dire.
Wrong detector, wrong relay.
Wrong method.


But you carry on.

What's wrong with the relay? It's a 12VDC reed relay from Maplins. Resistance - 1050Ω ±10%, Current - 11.4mA, Pull In to Maximum Voltage - 8.0 to 22

He just likes telling everyone they are wrong..

 

[Pithead]

It is dire.
Wrong detector, wrong relay.
Wrong method.


But you carry on.

What's wrong with the relay? It's a 12VDC reed relay from Maplins. Resistance - 1050Ω ±10%, Current - 11.4mA, Pull In to Maximum Voltage - 8.0 to 22

He just likes telling everyone they are wrong..

Indeed, I am not getting much further with my project. I am worried about blowing the components up with the 500mA PSU.

 

[bernardgreen]

The relay coil will determine how much current it takes... I = V / R You can only damage it by making the voltage to high as the resistance is constant. ( well almost, it will increase slightly if the coil gets warm due to prolonged operation.

The relay contacts will have to be rated to carry the current that the sind bomb takes. You will need to consider the inrush current of the bomb when sizing the relay contacts.

The sound bomb will determine how much current it takes as will the PIR so the 500 mA rating of the power supply cannot damage the relay. the sound bomb or the PIR. Only if the voltage of the power supply goes too high can the power supply unit damage the relay. the sound bomb or the PIR.

That is what you need to be careful about. If the 500 mA PSU has a minimum load current then if that minimum is not taken then the power supply may over volt.

 

[Pithead]

Thank you very much Bernard, much appreciated

 

[Pithead]

OK, found a 'no minumum load' 500mw PSU on ebay, will get the 1amp max carry load relay from Maplins later. Awaiting delivery of soundbomb.

Will let you know when the Noise Abatement Order arrives

 

[bernardgreen]

Bad news I'm afraid....... It seems cats soon learn that a loud noise can be ignored if it does not create any danger to the cat. They may avoid places where there are loud noises but if there is food or other incentive to be there then loud noises will not deter the cat. My cat was terrified of the new and noisy vacuum cleaner until he discovered it was all noise and no bite so he soon learnt to ignore it.

 

[lee2009]

10 liter container, spray them with a jet of water...

 

[Pithead]

Bad news I'm afraid....... It seems cats soon learn that a loud noise can be ignored if it does not create any danger to the cat.

Ah well, will try it out for starters

10 liter container, spray them with a jet of water...

Hmmm, I still don't want to go the super-geek route but if it's cheap enough I might. I've got an old PC running XP and can get a Miniature covert camera from Maplin for £20.

 

[Europlex]

'Google is your friend'

"cat deterrent products", there are numerous and more.