Im having difficulty finding a suitable circuit for my project. I want to (cheaply) create a 1Hz sine wave. I want to power it via 9v battery. I need this for a water activated stimulus. Two electrodes, placed in salt water, completes the circuit and is at a 1Hz freq. I have a few lm324's laying around and thought i could use them. Im just having trouble finding a perfect circuit for this, and I'm interested in any suggestions. Thank you.

 

Why do you need a sine wave? A square or sawtooth wave would be easier.

 

It would be much easier, i agree. The species I'm stimulating though has a peak sensing ability at 1 Hz. And the waveform should be sinusoidal because it resembles the prey species I'm attempting to mimic.

 

Pick one.

 

Thank you for your reply!

 

My favorite is the Bubba. Fig 15-18 in this app note. Lends itself well to a quad opamp.

Sim at ElectroTech

 

I like the Bubba oscillator because of it's low distortion and relative insensitivity to individual component tolerances (the frequency is close to the average value of the 4 RC values).

 

Will you run it permanently?

Pay atention to the time each one could take to start and stabilize.

 

It will be run for about 10-15sec/30sec

 

It will be run for about 10-15sec/30sec

What prey give a 1Hz sine wave? Where is a 1Hz sine wave emitted?

 

It's a ventilatory activity signal that sharks seek out. 0.5-2Hz
The literature suggests a sine wave produces the best result for stimulus.

 

It's a ventilatory activity signal that sharks seek out. 0.5-2Hz
The literature suggests a sine wave produces the best result for stimulus.

So, does just an electromagnetic emission/broadcast attract them or do you need some kind of physical compression of the water in a sinus mode.

 

Sharks have electrical sensors. Ampullae of Lorenzini...if I spelled it correctly.
Gel filled pores connected directly to a nerve, each.

Water movement is suspected to be irrelevant to those sensors.

 

That is true. Most fish movements are muscular and therefore use action potentials to stimulate said muscle to produce motion. These action potentials are picked up by animals that have an electroreception sense.
Thank you for the assistance with the circuit guys.