How can I make my own bilge alarm ?

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alec

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I have an auto bilge pump. I thought it might be fun to make my own alarm. Should be cheap enough, just needing some wire and a beeper.

Where do I start please

Thanks in advance.
 
Wire a smoke alarm accross the "test" button . High level bilges and bingo !! Try ignoring a rampant smoke buzzer . Also acts as a smoke detector in its normal mode . Two bits of useful kit for a fiver . /forums/images/graemlins/smile.gif
 
Well you can buy an led flashing type, wire to the terminal that feeds12 volt plus a buzer unit 12 volt wire to same and you have a £3.00 cheap alarm ive done the same on my bilge float feed ....Regards Roy
 
Aye, that\'s the one....

run a piece of tinned twin flex with the ends stripped and suspended in the bilge up to the test push and solder them on.

However, expect false alarms when condensation takes it's mischevious action in the small hours of the morning! Great way to get dis-approving looks from the Blue Duster Brigade in the morning.

Steve Cronin
 
Re: Aye, that\'s the one....

OK so apart from cheating using a smake alarm you need a switch which will activate with salt water bridging 2 electrodes. that is about 10000 ohms or .1 milliamp at 12 volts. This can be done using a transistor switch Field effect transistor for switching or easiest a CMOS integrated circuit. (Like a 4011) if you don't know what I am talking about get a book or forget it.

(If you don't know what I am talking about be gratefull you are not an electronics nutter.)

Perhaps it would be best if you PM me if you want to fiddle with electronics. Which can be fun but ultimately are so physically unreliable on a boat that they should be left home.
olewill
 
[ QUOTE ]
I have an auto bilge pump. I thought it might be fun to make my own alarm. Should be cheap enough, just needing some wire and a beeper.

Where do I start please

Thanks in advance.

[/ QUOTE ]

Maplins or other similar outlet for a Bath water overflow / level alarm. I have their dicontinued one that has a 1 mtr lead to the sensor .. I cut of the sensor as it was only a fancy piece of plastic looked like a flower with two pin contacts ... now just have the bare ends of wire.
The later Maplins one is a built in job and without lead ... sure that wouldn't defeat a penknife, screwdriver and soldering iron to add some lead ?

I checked my alarm on a meter and it's very very low current / voltage across the lead ... and in fact I can get it trigger with holding across 1 finger ! there's enough salt / moisture on skin to allow it to work ...

If you really want top play and have a game ... you can take a door or window alarm ... the reed contact job. Fix alarm part of the reed at height you want to detect to outside bottom of a tube. Tube has bottom castellated so that it can be glued to bilge and allow water in ... other non-lead part of the reed swicth is dropped into tube. Water comes in ... reed floats up ... other reed loses switch effect ... alarm sounds.

Another .... cut into auto bilge switch lead and have a buzzer from Maplins so that when switch activates ... buzzer sounds ...

****************************

It's funny as I have an auto bilge pump ..... and I thought of an alarm .. but then thought that the pump is going to keep bilge drained anyway - so alarm will "hopefully" never sound. If I put it anywhere else such as engine or shaft bilge - it will probably get too mucky to work properly.
 
Quite common on commercial vessels to put a bilge switch in line with a bell or buzzer, with the switch set higher in the bilge to warn of pump failure/blockage or leak faster then the pump can cope with.
 
Please don't put live wires into the bilge where current can be passed through the bilge water, or even via damp surfaces!
Get a washing machine pressure switch. Put it somewhere up in the dry, with a pipe going down to the bilge. As the water rises the switch is fired, wire it to a buzzer. You will have to experiment with pipe sizes, maybe put an inverted funnel on the bottom to 'collect' more pressure.
 
[ QUOTE ]
Please don't put live wires into the bilge where current can be passed through the bilge water, or even via damp surfaces!
Get a washing machine pressure switch. Put it somewhere up in the dry, with a pipe going down to the bilge. As the water rises the switch is fired, wire it to a buzzer. You will have to experiment with pipe sizes, maybe put an inverted funnel on the bottom to 'collect' more pressure.

[/ QUOTE ]

Please read my post again .... did I say put live 12v into bilge ? No I said that the bath alarm when I tested it with meter was very very low current and voltage ... I even tried a short to see if it would do anything .... nope. Not even a hint of spark or anything ....
A reed switch is sealed .... so no problem there.
Bilge auto switch is sealed as well ....

So what's the problem ? /forums/images/graemlins/wink.gif
 
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