Fish finders are great at locating the fishes lurking under the depth. They enhance your fishing experience and make fishing much more appealing. How do they do it?
Well, the screen that you see is merely a screen. The transducer does the main part of the magic. But what is a transducer? What does it do? Well, I’m glad you asked.
What Is A Transducer?
If you ever installed or seen a boat with a fish finder installed closely, you may have a head start here. Otherwise, a transducer is one of the most important parts of a functional fish finder. It is installed on the outside of a vessel.
A properly installed transducer is always submerged under the water level. A transducer is the sensor of a fish finder or a depth finder, or a similar gizmo. The devices sense the world using these probes. Transducers create sound waves and also pick up echoes, which is the fundament of these devices.
If you consider an echo sounder machine with a living body, the transducer is like the heart. The heart keeps the blood flowing, which is essential for living, only in our case, it is sound waves that are essential for functionality.
What Does A Transducer Do?
The job of a transducer is pretty simple. It creates a discrete sound pulse at a regular interval. As the machine is always submerged underwater, the sound pulses are created and traverse through the water. This is the first job of a transducer.
The second part is receiving the echo that is generated underwater. A transducer converts the electrical signal sent from the processor into analog sound pulses. Again, when the echo returns to the transducer, it then converts the analog sound wave into a digital electric pulse and sends it back to the processor.
Now, the electric signals are transferred through a cord connecting the transducer with the main body of a fish finder. A transducer has to be precise since it handles both incoming and outgoing signals through the same cord. There are more reasons for it to be extra precise. More on it later.
Structure Of A Transducer
From the outside, a transducer is pretty boring, not so much going on around them other than a good old cold. Depending on the model you choose, it may look like a solid box of rectangular or cylindrical shape (In-hull transducers) or some other regular or irregular shape (External transducers).
From the inside, though, things get a little more interesting. If you dissect a transducer, you can identify more or less five main parts. Starting from the outside is the housing that can be of plastic or metal.
It is waterproof and holds the sensitive parts inside, safe, and dry. Then comes some encapsulating materials. They fortify the protection as well as anchor the elements in place to prevent damage. The rest of the parts are technical parts.
Just beneath the encapsulation, there is a layer of sound-absorbing elements. They absorb any unwanted sounds to minimize interference of any sort. Saving the best, for the last, now comes the cord. It is straightforward. It connects the piezoceramic part with the main body.
What’s a Piezoceramic Thingy?
It’s a ferroelectric structure, usually shaped like a disk, but can also be of cylindrical or ring-shaped. This part takes the incoming electrical signal and transforms it into sound pulses.
This thingy also converts the returning echo sound back into an electrical signal. In short, this part is the main functional part of a transducer, and the rest is either to protect it or to support it.
How Does A Transducer Work?
A transducer (or on a bigger picture, a fish finder) works on the same principle that a bat uses for locomotion, or a dolphin/bat to locate their prey.
I mentioned this briefly before that they make sound pulses that travel through water and returns after being reflected. Isn’t that supposed to scare the fishes away?
Have I mentioned that the sound wave is ultrasonic? It is way above the hearing limit. And fishes are kind of not so great at hearing either.
An average transducer is capable of producing sound pulses from 50kHz all the way up to 200kHz. But the extreme ones may range from 10kHz (if in the lower range) or 2MHz (one on the higher edge).
Remember the piezoceramic thingy? It shakes rapidly when electrified. The vibration is passed through the opening of the transducer and released on the open water.
Because of the structure of a transducer, the energy can only pass through some specific area of the transducer, usually the bottom part.
- Identifying Objects
The pulses travel through the water, and whenever an object comes in the way of the sound wave, the object creates an echo of it.
Different objects (fish, weeds, rock, hard or smooth seabed) create different types of echo, that is used to identify different objects. Oh! I was talking about seaweeds, not weed weeds. Get your head out of it already.
A transducer usually makes a very short pulse, and then goes into full silence, waiting for the echo. After a certain amount of time, it creates the next pulse.
Sound travels fast through the water. So, In almost all scenarios, the echo will return before the next pulse is sent.
Once the echo returns, the transducer picks it up and creates a corresponding electric pulse. The strength of the echo determines the strength of the electric pulse.
The fish finder calculates the time difference between the sent pulse and received pulse to work out the depth of the object, and the strength of the pulse to show the type of the object.
All these happen within a fraction of a second.
The Importance Of A Transducer On A Fish Finder
In a horse race, A racer is as good as the horse is. Of course, the racer is important. But he can never win if the horse is not capable of. The transducer is the horse to the fish finder. A quality transducer can make a drastic change to the output of the same fish finder compared to having a trash transducer.
Remember, I said, a transducer has to be precise? That’s because a transducer works within a fraction of a second, and within that small window, many floating objects (hopefully fishes) make a lot of individual echoes that are jam-packed closely.
The transducer needs to be able to understand every single one separately. Otherwise, you’ll get a messed up blurred line on your screen.
To sum things up, a transducer is the ear (also mouth) of a fish finder. It senses the ocean through the transducer. If the transducer isn’t good enough, your grandeur fish finder will not stand up to the service the seller promised you. To me, it’s a wonder how transducers work. But then again, nature is more wonderful.
Anyway, the knowledge about the transducer might not help you catch more fish. But it might help you understand a few things, like whether you need a change or not. I hope I made sense in my discussion. I hope you have a great fishing trip.
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