FF fading in and out

AC has a natural zero twice which is where a breaker is typically used to interrupt the circuit. DC do not alternate so they do not have a natural zero state. Think of an arc welder or a car battery. Short the circuit without a load to disspate the energy to heat and something will pop whether its your power source or your electronic device. DC fuses are faster than AC so use the appropriate fast acting fuse rated for DC. Salt water is an excellent conductor as is corrosion and dust when it comes to electronics which is where you can exhibit a short in an orherwise healthy looking system. So if you value your hard earned dollar, dont neglect the $.03 fuse because its a lot cheaper than replacing electronics.

Yup..still don't get it...the system is operating off a battery with no charging system.

Its not so much about a power supply since the battery is your power supply in this DC circuit and batteries can  short internally. Equipment components only draw what they are designed to draw, when something goes awry inside the equipment or battery supply and theres to much current with no fuse, you are feeding the dog until kibble pours from its throat and dies. Since currwnt is inversley proportional to current, when a component shorts inside the equipment; resistance decreases and current exceeds the rating of the next weakest component and so forth and goes unchecked.

Whether its printed circuit board or silicone based technology, it is designed for current/ voltage to flow in a linear fashion, not jumping runs to be shorted.

Whether you use a fuse or not, makes no difference to anyone but the user. Its cheap and replaceable and is no different than car insurance.

Simple answer is that if your electrical system develops a short somehow, the current flowing through the short can grow very high, very quickly, causing the wires to heat up enough to cut through the plastic your kayak is made out of like a hot knife through butter.  A fuse is well worth it in my opinion.  Use a fuse that is rated for the current your fish finder consumes rounded up to the nearest standard value you can find off the shelf.

Its not so much about a power supply since the battery is your power supply in this DC circuit and batteries can  short internally. Equipment components only draw what they are designed to draw, when something goes awry inside the equipment or battery supply and theres to much current with no fuse, you are feeding the dog until kibble pours from its throat and dies. Since currwnt is inversley proportional to current, when a component shorts inside the equipment; resistance decreases and current exceeds the rating of the next weakest component and so forth and goes unchecked.

Whether its printed circuit board or silicone based technology, it is designed for current/ voltage to flow in a linear fashion, not jumping runs to be shorted.

Yes I know, I'm not simple...I get the concept. I just don't see a need nor have I ever heard of anyone frying a fish finder on a Kayak because they didn't have a fuse installed...I have heard of several kayak fisherman whose fish finders did not work becuase they were running a fuse...which got corroded and failed.

Why you are offended, I dont know. You provided nothing more than " I dont get it" responses so the natural response is to provide an explanation.

It also has nothing to do with whether it is a kayak FF or on a motorized vessel. Electronics in a marine enviroment are all exposed, kayaks more so if anything.

You are attempting to apply inductive reasoning which wont work. Fish finders on kayaks are less than a 10th of a percent if vessels equipped with electronics so natural failures that occur will be more noticeable. You will never remember that 5,000 fish finders on kayaks worked great and 5 failed. The ones you remember are the 5 you heard of unless you know everyone that had one and the condition of that electronic device.

What im getting at is that just because a fuse holder was not properly weatherproofed for marine use, does not mean the fuse holder is the reason for all failures.  This is the same as saying kayaks used equipped with fishing rods all smell like rotten fish therefore its the fishing rods fault when in fact it is the user that did not scrub the kayak and the fishes natural slime that caused the offensive odor. Even though not all fishing kayaks dont smell like rotting fish just because they are equipped with rods.



-Will

Why you are offended, I dont know. You provided nothing more than " I dont get it" responses so the natural response is to provide an explanation.

It also has nothing to do with whether it is a kayak FF or on a motorized vessel. Electronics in a marine enviroment are all exposed, kayaks more so if anything.

You are attempting to apply inductive reasoning which wont work. Fish finders on kayaks are less than a 10th of a percent if vessels equipped with electronics so natural failures that occur will be more noticeable. You will never remember that 5,000 fish finders on kayaks worked great and 5 failed. The ones you remember are the 5 you heard of unless you know everyone that had one and the condition of that electronic device.

What im getting at is that just because a fuse holder was not properly weatherproofed for marine use, does not mean the fuse holder is the reason for all failures.  This is the same as saying kayaks used equipped with fishing rods all smell like rotten fish therefore its the fishing rods fault when in fact it is the user that did not scrub the kayak and the fishes natural slime that caused the offensive odor. Even though not all fishing kayaks dont smell like rotting fish just because they are equipped with rods.



-Will

Offended? I'm not offended at all...when I said I don't get it, I didn't meant that I don't understand electricity, but rather I didn't see the value in using a fuse and adding a potential failure point. You obviously believe quite strongly in the use of a fuse...I recommend you use one. As for my own experience, a fuse has been the only thing that has ever caused a fish finder not to work in one of my own personal kayaks.
FWIW, motorized vessels normally have a charging system and would certainly need a fuse...comparing power boats and kayaks in this case is not relevant. rotting fish? what?

The validity of a fuse has been pulverized and you are obviously well versed in this field so there is no point in discussing this further. So HAGO.


-Will

Its not so much about a power supply since the battery is your power supply in this DC circuit and batteries can  short internally. Equipment components only draw what they are designed to draw, when something goes awry inside the equipment or battery supply and theres to much current with no fuse, you are feeding the dog until kibble pours from its throat and dies. Since currwnt is inversley proportional to current, when a component shorts inside the equipment; resistance decreases and current exceeds the rating of the next weakest component and so forth and goes unchecked.

Whether its printed circuit board or silicone based technology, it is designed for current/ voltage to flow in a linear fashion, not jumping runs to be shorted.

Yes I know, I'm not simple...I get the concept. I just don't see a need nor have I ever heard of anyone frying a fish finder on a Kayak because they didn't have a fuse installed...I have heard of several kayak fisherman whose fish finders did not work becuase they were running a fuse...which got corroded and failed.

It's not about frying the fishfinder.  By the time a the fuse comes into play, the FF is probably already toast as that is what led to the current rush in the first place.  But if you have a dead short in the FF, your power wires could heat up enough to catch fire or melt a hole in your kayak.  A 7Ah SLA battery has a short circuit current in excess of 200 Amps!

-Allen

Fuses are for protection twofold. Not only for equipment but as you stated, safety. The discusdion was regarding the validity of the fuse. Safety, equipment failure were both used as example. See the arc welder and shorted battery cable post.

As far as a equipment beint toast if it were shorted internally befre the fuse can help, yes I agree. If the short occurs in the connector going to the equipment, the fuse can prevent damage. Thats why its important to use proper fuse whether they are quick acting, slow blow, dc,ac, G, J, CC, double filament, etc for your application.

I was under the impression that Nangusdog did not understand so I was attempting different approaches. But like I said, this threads becoming tedious. Not because I am incapable of explaining but because you cant have a conversation when one party has already made up their mind. And ad far as my understanding, I do have an understanding of electronics and I tear into equipment the majority of the population will never see and equipment no one will see again. This became an argument instead of helping someone long ago so I really am removing myself from this thread. This time for real:)

-Will

Fuses are for protection twofold. Not only for equipment but as you stated, safety. The discusdion was regarding the validity of the fuse. Safety, equipment failure were both used as example. See the arc welder and shorted battery cable post.

As far as a equipment beint toast if it were shorted internally befre the fuse can help, yes I agree. If the short occurs in the connector going to the equipment, the fuse can prevent damage. Thats why its important to use proper fuse whether they are quick acting, slow blow, dc,ac, G, J, CC, double filament, etc for your application.

We could probably write an entire book on what could be happening with this simple electric system and the fundamentals of protecting it.

So ... what is the "proper fuse" for this application?  And why?

-Allen

This thread:

I was under the impression that Nangusdog did not understand so I was attempting different approaches. But like I said, this threads becoming tedious. Not because I am incapable of explaining but because you cant have a conversation when one party has already made up their mind. And ad far as my understanding, I do have an understanding of electronics and I tear into equipment the majority of the population will never see and equipment no one will see again. This became an argument instead of helping someone long ago so I really am removing myself from this thread. This time for real:)

-Will

One of the beauties of sites like this is that it brings together people of varying knowledge levels on miscellaneous topics.  But the written form of communication often makes it hard to convey the message appropriate to the various knowledge levels.  I'd suggest simple, concise responses until you get to know the people you are communicating with.  I find that treating the topic as a conversation, and not as a lecture, helps to avoid any misunderstandings.

-Allen