nicknorman

It’s clearly AI generated. If it were real there would be hundreds of shouts of SLOW DOWN!

A 12v appliance with a 230v plug on it could easily be removed from a boat lacking mains voltage and plugged in to mains in a house etc. Probably not by the boat owner, but his relatives after he dies/has to leave the boat, or the next owner. I can only think that people who think this is OK have never been involved in accident analysis. Just because a bodge is adequate in a very specific situation, doesn't mean that when circumstances change in an entirely predictable way, it does not become a serious safety issue.

Agree with the principle but not the reason. Core saturation has nothing to do with passing continuous dc current. But as other have said, having a 13A plug on a 12v dc appliance is very foolish and dangerous.

I think it was that Tony thought the quote for the new loom was very expensive and probably unnecessary, and if he were in your shoes he would have responded to the engineer with a rude word. Well he probably wouldn’t actually, it was just a figure of speech to indicate he thought it was a rip-off.

Because you have to store it somewhere Because it smells of diesel Because you have to undo the cap and redo it afterwards - risk of dropping in the cut Because it’s easy to introduce contaminants into the tank, including bug Because you can’t really do it when it’s raining or at night Because it is not “in your face” and one day you might forget and run out. Because in our case there is not a straight path into the tank from the filler. But apart from that, as you say there is no reason.

I know, but if you can make something that consumes microamps, why make something that consumes milliamps. Although of course with something like a tank sender, it could sleep for 99% of the time and only be powered for 1% to take a sample since the rate of level change is slow.

I rather resent the unnecessary overhead of up to 20mA doing nothing useful. Yes of course 4-20mA is an industry standard interface, but it’s also a very old industry standard! As in 70 years or so old!

I think there are pressure sensors and … pressure sensors. If you go for one that is just a bridge circuit with no amplification or signal processing, and only using a small proportion of its range, you get a very small and temperature-dependant voltage. Analogue electronics = too much hassle! Whereas if you get a sensor with integral signal processing and eg an I2C or SPI digital interface, then it’s a piece of piss once you have sorted out the interface drivers (for which there is probably an arduino library).

You can add the pressure sensor anywhere before the pump that is vertically near the bottom of the tank, since there is no pressure drop when the pump isn't running, it is only a matter of the height difference.

That is fine if your life is formulaic. For us as “part time” boaters with a washing machine and occasional parental trips, water consumption was very varied. Before we had the gauge we would needlessly stop for water. Now we have it things are much more controlled, as someone said, would you prefer to have a car without a fuel gauge and just rely on noting the mileage? I had motorbikes like that. But in the 1970s. And they had a fuel reserve tap.

Since the Cerbo only accepts a resistive input (eg a tank float moving a wiper over a wire wound resistor) the easiest way would be to use the GX tank 140 interface and use an opamp etc to adjust the output span of the pressure sensor to the 0-10v the GX tank expects. If I were doing it I’d probably use an I2C output pressure sensor with microcontroller controlling an electronic potentiometer straight into the Cerbo, but I have invested a lot of time to be able to do that easily.

The easiest way to sense water tank contents is by measuring the static head of pressure at the tank outlet. This is typically by means of a T piece and pressure sensor as per the MCS water tank gauge. Obviously it doesn’t read properly when the pump is running but it reads accurately at any other time. A flow meter will suffer from cumulative integration errors and issues if you don’t fully fill the tank.

No, No, No, Yes, Yes. I’ve been building some small items with Bluetooth. The little Bluetooth modules cost £2.20 retail in one-off quantities. So the delta on the cost of say a £100 product is insignificant and adds a lot of convenience. It is true that it can’t be used to make fire by rubbing sticks together so I can see why you are anti.

We have the MCS fuel gauge, top entry onto the tank. It does rely on not losing any air pressure ever, but of course it does, slightly. I have to pump it up about once a year but it only takes a few minutes. In the OP’s case I have no idea what sort of input the Cerbo needs. The sensor for the MCS device is a pressure sensor which is a bridge, so the output would be very small and some amplification would likely be needed to get it into a range suitable for the Cerbo. Or just steal the principle and find a low pressure sensor with a suitable output, the rest is just plumbing. https://www.mcsboatproducts.co.uk/our-products/fuel Edit: looks like they’ve changed the design. Ours had a Schroeder air valve to top the pressure up in the down-pointing pipe, and it was much narrower than the type shown.

Never thought of that before, it’s a great idea. Well it would be if you have a tank like yours. Our tank is under the engine with a long flexible and slightly curving filler pipe from gunnel to the tank. Which is why we have an electronic gauge!