Two octaves above middle C# is 2093Hz. All the electronics is already inside a piezo beeper so get one, a battery and a push button.
Then the cats will run into the kitchen when a smoke alarm is tested or is activated.

 

AG wins with the simplest solution.

Bob

 

I think two octaves active middle C# is half that.

Bob

 

I think two octaves active middle C# is half that.

Bob

So, do you still think this is true?

AG wins with the simplest solution.

Bob

 

Then the cats will run into the kitchen when a smoke alarm is tested or is activated.

Sounds like how we knew dinner was ready at my mother in laws house, ready to serve when the smoke alarm goes off.

 

Middle A is 440Hz and C is a little higher at 554.37Hz. I was wrong and said middle C is 553.25Hz.
One octave higher than middle C# 554.37Hz is 1108.74Hz and another octave higher is 2217.48Hz.

I do not have Covid-19 so I can still smell when dinner is ready.
Hey, it is snowing like crazy outside.

 

Two octaves above middle C# is 2093Hz.

UM - THIS looks like it's saying Mid-C is 261.624Hz. Two octaves is reportedly 1046.502, not 2093Hz. That is if you can believe everything you read on the internet. Yet, I've looked at several sites that didn't agree with AG's remarks. Having found no conflicting information, I'm going with what I'm seeing.

Hey, it is snowing like crazy outside.

75˚F forecast for here.

And I have a bunch of NE555N's in my stockpile.

So what's the P-Channel version of the 2N7000?

 

I'd just retrain the cats. When I let my cats outside, I supervise them. If I lose track of them, I clap and they usually come running back to our deck. When I want them to go in, I snap my fingers.

When they're being bad in the house (usually clawing on something), I can snap my fingers from anywhere in the house and whichever cat was being bad stops. I find it interesting that only the cat doing something bad reacts. I have no idea how they figure out how to react to me snapping my fingers at them.

 

UM - THIS looks like it's saying Mid-C is 261.624Hz. Two octaves is reportedly 1046.502, not 2093Hz. That is if you can believe everything you read on the internet. Yet, I've looked at several sites that didn't agree with AG's remarks. Having found no conflicting information, I'm going with what I'm seeing.

75˚F forecast for here.

And I have a bunch of NE555N's in my stockpile.

So what's the P-Channel version of the 2N7000?

I'm not sure anyone made one. You can do it with bipolar transistors too. You'll just need a base resistor. Also, thinking a bit more, a group of four resistors will be better than one shoot through protection resistors because the one amp current x 4.7 = 4.7v drop. That moves the N-channel Mosfet up 4.7 and makes it a bit harder to turn the gate on completely.

 

I would try a simple NE555 timer circuit and a piezoelectric tranducer, no amplifier required.

 

A little something about these two cats. Castor and Pollux (brother and sister born May 9th last year). Castor is the male and Pollux is the female. Polly is a scardie-cat. Castor is the adventurous one wanting to go all the way around the block. That's bad news because he's a friendly cat. Someone will pick him up and love on him and maybe think they can keep him. He's chipped so as soon as anyone takes him to a vet I'll be notified immediately. And he hates cars. One drives by and he's running for cover. Probably because one winter evening he snook out and we didn't know it until bed time. Meanwhile he was locked out in the cold and loud cars going by really unnerved him. So I'm glad for that. He's also wary of dogs. But I doubt he'd know how to handle himself if he encountered one. So I want to be able to return him home from down the street if that's where he is.

When they start to get a little too far I want to be able to have them come running home. So I don't know that the piezo will be effective. That's why I'm thinking about the loud horn speaker. I DO like the idea of powering it from a 9V battery. Simple and easy enough to get a hold of one or two. The horn will be hand held, not mounted anywhere.

As for scratching on stuff, all three know where they're allowed to. Anywhere else and they get yelled at. Castor is stubborn though. He likes to climb into my scrap pile of junk and I don't want him in there. Nothing he can get hurt on but I don't want him knocking over the neatly stacked pile. He DOES knock things over.

I'm always uneasy when they're out. But mostly they want the door open so they CAN go out IF they want to. Close the door and THAT's when they want it open. Right now it's open and they're sleeping in their beds. Go figure.

 

A 440 is the A above middle C. Middle C is about 262.

Middle C

Bob

 

So, do you still think this is true?

Why are you so hostile toward me?

Bob

 

Why are you so hostile toward me?

Bob

It's not hostile, I'm just wondering what your current thoughts are when you realized AG's proposal didn't meet the objective on frequency.

 

Well, you are wrong about that. I find 5 piezo buzzers on Mouser at 1100Hz which I doubt that a cat can distinguish from 1108Hz.

Bob

 

Well, you are wrong about that. I find 5 piezo buzzers on Mouser at 1100Hz which I doubt that a cat can distinguish from 1108Hz.

Bob

So, your answer was, "yes". Right? I can be wrong for asking you a question.

 

AG got the frequency wrong, as we seem to agree. But his suggestion of using a piezo buzzer is still the simplest solution proposed since piezo buzzers exist that are close enough to the requested frequency. Does that clarify my position sufficiently for you?

Bob

 

AND this doesn't need to be an exact tone, just something relatively suitable to what I'm trying to describe.

Doesn't sound like the TS wants some exact tone. More of somewhere in the range of what he's determined to be an approximation of a tone he's looking for.

 

Well, you are wrong about that. I find 5 piezo buzzers on Mouser at 1100Hz which I doubt that a cat can distinguish from 1108Hz.

Bob

A link would be helpful.

Been testing frequencies on YouTube. Searching 1000Hz frequency resulted in a tone that was a little lower than where I'm hoping to go. 2KHz was a little higher than what I think I want. Somewhere around 1.5KHz sounded closest to what I think I'm after.

Doesn't sound like the TS wants some exact tone.

Just to confirm this - yes Pan, I'm not looking for an exact tone, just something around a general whistle you make when you pucker your lips. And no, I'm not asking you or anyone else to pucker for me.