What does it do ? Well , it generates a sound similar to the sound that a water drop makes when it's dropped in a bucket or any other plastic object.
You can adjust the frequency of the drops by rotating a variable resistor , and it works with voltages between 6v and 3v .
Step 1: Parts
So , what you need is :
--1 General Purpose NPN Transistor (prefferably 2N3904)
--1 General Purpose PNP Transistor (prefferably 2N3906)
--1 10 Microfarad Electrolytic Capacitor
--1 Battery holder
--1 Variable resistor (100 K ohm)
--Your favorite soldering tool
Step 2: Building It
Follow the scheme included in this step to see how to make the device.
You can also use a 100K fixed value resistor for the circuit , but it won't work with all voltages.If you use a variable one , you can adjust it to work with the voltage that you're feeding the circuit with.
Step 3: Finishing It
So, get a box and put everything together.(Notice my ugly box?)
As you can see in the photos , i used a 9V battery clip for the power source because i had 2 battery holders with the same connections .(1 was giving 3V and the other 6V)