Notice to YSPilots/YSFLIGHT

Notice to YSPilots/YSFLIGHT
Legacy Pack available under the YSFLIGHT category.
Any individual requests for a model must be made to my email address, see bottom of the page..

Wednesday, 5 February 2014

Simple Hydrophone (Mk1)

This little project is for making a simple hydrophone.
What is a hydrophone?
Well, a hydrophone is an underwater microphone. Basically…
My initial plan was to make 2 hydrophones that would work together to produce a “3D Image” of the sound, Sonar. The theory behind this was that sound coming from a certain direction will hit the microphone nearer the sound source first, then the second one, the delay in the signal would give an angle to the sound source. The idea from this was to create a “waterfall display” which would show if there was sounds coming from different directions, it would show all the bearings around the microphones, and lines of high intensity would flow down from the bearings where a sound source existed, be it a boat or a dolphin.
Complicated stuff.. That was the problem… I had no idea how to produce that…
So, instead I decided to make a single hydrophone, and just to listen to what was under the water!
Much easier!
My basic ingrediants are:
A Microphone (From RS Online)
3.5mm audio jack (Also from RS Online)
Camera film case (I got them for free from a local camera shop)
30m Ethernet cable
Ethernet Keystone Punch Down Jack (A plug!) From Amazon
A bunch of electrical dohickies, but I’ll come to that later!
So, the initial design was just to trail the microphone in the water, in the camera case, and plug the output straight into the 3.5mm jack and plug that into the computer.
Good! But, the output was incredibly weak, and full of noise, so I had to put an amplifier on it…
I did electronics at A-level, but I cannot remember much… OP Amps, I remember can be used as an amplifier (the amp part…). I tried that, but with no joy, so I used a transistor instead.
So, this is my amplifier circuit. It’s not especially advanced, and to be honest I just slapped it together, but it worked! I tried some different designs that I thought would be better, but for some reason they didn't work.
So, this is my current stage
I’m waiting on my ethernet jack. I’m then going to use the Ethernet cable as the trailing cable from the hydrophone to the computer. I’ll put the microphone output into the ethernet cable, then the ethernet cable will run to the surface, where it’ll plug into the amplifier, and then into the 3.5mm jack into the computer.
This output can then be recorded and listened to. My camera is currently not working, so I can’t post pictures at the moment.. But they’ll come!

No comments: