Cat Whistle, electronic circuit to make a short whistle help.

Thread Starter

Tonyr1084

Joined Sep 24, 2015
6,887
It hasn't been since high school that I messed with an amplifier circuit. What I'm looking for is quite simple. An amplifier and whistle circuit that operates with the push of a button. Push the button the whistle blows. Release the button the whistle stops.

Here's the weird part - we have two new cats. Will be a year old in May. When they hear a whistle they perk up and run to the kitchen for some reason. I don't know if the person who gave us the cats whistled before feeding them but we've discovered that a whistle will call them from just about anywhere. It's better than calling their name or shaking a treats bag.

The circuit needs to be simple. Just push the button and a speaker emits a fairly loud high pitch whistle. The note I'm thinking of is a C sharp. I'm no piano expert but the note I like is two octaves above what I think is a middle C sharp. A single tone, no complicated, no "C Major" or "C Minor" or "C 5" (looking at a chart). Power source can be a battery of some kind. The note will be seldom used so battery life isn't a major concern. AND this doesn't need to be an exact tone, just something relatively suitable to what I'm trying to describe.

The other day I wanted to bring them home so I whistled a short whistle about a second long and the two of them came running and they ran inside the house. (Oh, and let's not get into a discussion about allowing cats out of the house - we don't need to go there. I understand your concern. It's our decision. Not yours.)

I also don't want to spend a ton of money on this. If I have the spare parts to make this I will. Otherwise if I need to order something - so-be-it. Relatively simple is probably the best way to go about it.
 

Thread Starter

Tonyr1084

Joined Sep 24, 2015
6,887
Thought about the 555 for the frequency. I've built plenty of 5^3 circuits. The part I'm uncertain on is the amplifier. I don't know how many watts I'd need or if I could by something (probably can). Unsure of the speaker type. I'm thinking something like a bull horn with a whistle button. Loud but not so loud you need hearing protection.
 

MrSalts

Joined Apr 2, 2020
1,762
What kind of whistle? Referee, fluke-like, mouth puckered, two finger under tongue? Or doesn't it matter - the cats respond to any tone.
 

Dodgydave

Joined Jun 22, 2012
10,305
If you use a CD,4093 you can use two gates as the speaker driver in push pull mode, this will give you a louder sound, you could buffer it with transistors.
 

Thread Starter

Tonyr1084

Joined Sep 24, 2015
6,887
mouth puckered
Referee is not necessary. Not sure what "Fluke-Like" is. Two fingers - generally suggests (in my mind) a changing tone. It probably doesn't matter.

Like I said, a bull horn whistle seems to be a good analogy. Also coming to mind is those chirps when you set your car alarm. As for speakers I'm thinking of an outdoor PA type horn speaker like the things we used to put under the hood facing the grill attached to our CB radio's back in the 70's. They seem to be pretty loud without a whole lot of power.

Hey! I'm spitballing here.
 

Thread Starter

Tonyr1084

Joined Sep 24, 2015
6,887
you could buffer it with transistors.
Probably the way to go. But will that be sufficient power? From the attached speaker link I'm not looking for thousands of watts of power, 10 watts is probably loud enough. I think! Hence: What voltage would I need to come close to 10 to 15 watts?
 

Thread Starter

Tonyr1084

Joined Sep 24, 2015
6,887
I don't know if other cats would respond. I have an older cat (12 years) who doesn't give a meow about the whistle sound. She ignores it like her least favorite food at meal time.
 

BobTPH

Joined Jun 5, 2013
4,906
The LM386 data sheet has a circuit for a phase shift oscillator that can directly power a soeaker. That would give you a load sine wave with only one chip.

Bob
 

MrSalts

Joined Apr 2, 2020
1,762
If a 4w square wave works for you, a simple H-bridge works to get a short blast at nearly 4W.
Use an Energizer Ultimate Lithium 9V. It's good for 1A (9W for a few seconds and will never leak.

The shoot-thru protector resistor simplifies so you don't have to worry about a dead-time between transitions. Adjust discharge resistor to get the exact frequency you want.

4374309E-A4B4-4738-BD7F-D064E756A870.jpeg
 

Thread Starter

Tonyr1084

Joined Sep 24, 2015
6,887
Check out the square wave oscillator on page 14.
Twice the number of components (not counting the H Bridge). Not that this is a problem; the 555 will do the same job with less peripherals. With what I've learned so far I think, after checking my stockpile, I will be moving forward with this project.

My IC Stock is on my other computer in the office. I'll have a look to see what I have when I get in. It's nice being retired.

I DO appreciate all the input. I don't expect this thread to be a lengthy thread; just something to point me in the right direction.

I DO have one more question concerning the H Bridge - will a 2N7000 work along with (I think it's) a 2N7001 (the reverse polarity of the 7000).
 

MrSalts

Joined Apr 2, 2020
1,762
Yes you can. Check out the square wave oscillator on page 14.

I remember a phase shift oscillator, but I haven't found it. This datasheet also had a Wien Bridge if you want a less annoying sound.

LM386

Bob
But that single amp circuit oscillates between ground and Vcc. The Full bridge I showed will have 4x power with effective voltage delta from "off" to "on" being -Vcc to +Vcc.
 

MrSalts

Joined Apr 2, 2020
1,762
Twice the number of components (not counting the H Bridge). Not that this is a problem; the 555 will do the same job with less peripherals. With what I've learned so far I think, after checking my stockpile, I will be moving forward with this project.

My IC Stock is on my other computer in the office. I'll have a look to see what I have when I get in. It's nice being retired.

I DO appreciate all the input. I don't expect this thread to be a lengthy thread; just something to point me in the right direction.

I DO have one more question concerning the H Bridge - will a 2N7000 work along with (I think it's) a 2N7001 (the reverse polarity of the 7000).
No, I think the 2N7001 is just the SMD version of the 2N7000
 
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