epilot
Member
Hello,
I have made an ultrasonic pest repeller based 555 IC(it has a volume for changing the freq).
As you know these devices work with ultrasonic sensors or tweeters,
but I connected the output of 555 via a capacitor into a common 4 or 8 ohm loudspeaker; just to see what will happen(I knew that the diaphragm is not suitable for ultrasonic frequencies),
I had an audible sound(like whistel) at ultrasonic frequencies too!
Can anybody explains the reason?
Ok, the diaphragm is not suitable, but why any sound at that freq???!
I have made an ultrasonic pest repeller based 555 IC(it has a volume for changing the freq).
As you know these devices work with ultrasonic sensors or tweeters,
but I connected the output of 555 via a capacitor into a common 4 or 8 ohm loudspeaker; just to see what will happen(I knew that the diaphragm is not suitable for ultrasonic frequencies),
I had an audible sound(like whistel) at ultrasonic frequencies too!
Can anybody explains the reason?
Ok, the diaphragm is not suitable, but why any sound at that freq???!