555 timer frequency change problem

[Hero999]

This circuit will be fine as long as the power supply voltage is below 6V.

When powered from 6V it will produce as much ultrasound as the 555 circuit does when powered from 12V.

I assume the piezo doesn't use much power? The maximum output current of this circuit is 50mA.

 

[Thunderchild]

something like that, a fully integrated counter will give you a 1000 division with flipflops you will have to use a number of IC's to get the same result

 

[Hero999]

Why would you need a counter? He wants 40kHz, the circuit uses a 40kHz crystal, only one IC is needed.

 

[Thunderchild]

in the event he uses a higher frequency cystal, but I hope he gets a 40 KHz one

 

[i12know]

yup, i assume they have a 40kHz one here as well. But will only get one after the long weekend which starts tomoro!! Thanks a lot guys for all the feedback, really appreciate that!