beef-up an "ultrasonic" amplifier

[Dave]

I have a cheapo ultrasonic pest repeller thing that's just an osc/amp + small
speaker. What I'd like to do is remove the speaker and feed the signal into a
more powerful amp then use that to drive a tweeter. The freq. is about 25-30kHz.
Has someone got a *simple) circuit I can use to do this please? I only have a
multimeter (no 'scope) so I can't see if it's working. I don't want to build the
osc. from scratch because, as I say, I have no 'scope to see it's actually
working.
tia

 

[Joerg]

Hi Dave,

Please mind dogs, pets and wildlife in your neighborhood. They can often hear this
range and to them it may sound like a car alarm constantly running in your living
room would to you.

Regards, Joerg
http://www.analogconsultants.com

 

[Ron Hubbard]

"Dave" <Dave@local.here> wrote in message
news:1vch90t9tiqbho0j3g2br5lk9caevv4c0k@4ax.com...

I have a cheapo ultrasonic pest repeller thing that's just an
osc/amp + small
speaker. What I'd like to do is remove the speaker and feed the
signal into a
more powerful amp then use that to drive a tweeter. The freq. is
about 25-30kHz.
Has someone got a *simple) circuit I can use to do this please?
I only have a
multimeter (no 'scope) so I can't see if it's working. I don't
want to build the
osc. from scratch because, as I say, I have no 'scope to see
it's actually
working.
tia

Dave, you might try connecting the output of your pest repellor
into the input of a LM384 amplifier. That should give you several
watts of acoustic power.

Ron