>>>Electronic dog wistle

[Someone Electro]

I want to build a electronic dog wistle!

I want it simple!

T have the shematic for a modilator but i dont know what walues i need to oscilate at 25-40 kHz

It can be just a oscilator as long as it oscilates at 25-40 kHz.


PS:
My first ultrasonic experement was that i inputed 25 kHz to a speacer and opend the window(of course the dogs gone nuts)

 

[dingo]

2 x 1k resistors and a .01 cap will give you 48khz with a 555
1k trim pot, 1k ohm, .01 cap & 555 should cover that range.

Don't know what values you need for the circuit above but you can borrow my resistor wheel and CRO if you want

 

[Someone Electro]

I have a potencimeter but i dont have a variable resistor.

Your in Australia and im in Evrope sending the thru mail can be expesive

I will try whith a potencimeter. and use the smalest cap i can find lets say 3

First i have to get the compnents.I think there in my junk box.

PS:
I dont have a 555 ! :cry:

But a got a 5A Power NPN transistor.Perfect for amplafifing!So i can use a big speacer! :twisted: (Its a BUT11AF)

 

[Someone Electro]

It works but just 2-3 dog got the beep.So i need to amplefy the signal.

Whats about pico-buzzers i have one do they work beter than the speacer(i mean 20 - 30 kHz beeps)

 

[dingo]

try using a tweeter should work a lot better than a normal speaker

 

[fat-tony]

I have a potencimeter but i dont have a variable resistor.

Same thing