PaulG

The picture posted in another thread of the "weather forecasting cat" reminded me of this high tech device:- Anyone else got any favourites?

Depending on direction of prop rotation, most boats will have a pronounced "kick" to one side or the other when reversing. My own boat follows a slow curve to starboard when going astern. This is curve is reduced, but not entirely eliminated by use of the rudder. Every so often it is necessary to give a short burst of "ahead" power whilst reversing the lock on the tiller to get the boat going in a straight line. It's easy with practice (I have to reverse 50 yards or so very time I leave my berth). Oh, and of course, we never forget to give three blasts on the horn for "going astern", do we?

This might do the trick! http://cgi.ebay.co.uk/Morso-Squirrel-Stove...1QQcmdZViewItem

Yup, I'd go for brown, too. Matches the boat name....except...I suppose you could paint it in "blues", but that might just be too subtle?

European Waterways announces "veg pledge" success. Wasserstraßen-Chef Karl von Munchausen, speaking from the central office in Berlin in the former republic of Germany said " I know that some people have criticised the project because of it's hundred-year timespan, and I recognise it has taken a bit longer than our predecessors, British Waterways, anticipated. However, I would point out that it was quicker than commissioning Terminal Five at Heathrow, where some customer's bags are still awaiting collection."

I know you don't really need them since European Waterways' Health and Safety department put the towpath lights in, but I've just found some vintage LED cabin lights. Can anyone remember how these work? Should I set fire to them, and if so, how long will they burn for?

Spent two days in centre of Brum last summer. Lively but not too noisy, plenty of bars , restaurants and pubs. We moored outside a nightclub and the bouncers were happy to keep an eye on our boat. Quite safe, IMHO - we'll be mooring there again this year. Can't comment on Leicester 'cos I've never boated there. Probably alright as long as you don't have a "Northampton Saints RFC" sticker in your window! Paul

I'd talk to their registration office:- http://www.shakespearesavon.co.uk/contact.htm I've always found them very helpful. I'm based on the Avon, so I'm biased, but it's well worth a visit! Paul

Sorry to be pedantic, but the Avon is not EA. You need a LANT licence for the Tewkesbury-Evesham section and a UANT licence for the Evesham-Stratford section. Short term licence to cover both sections is available from the lockie at Tewkesbury lock, cost £44. Paul

Slightly off topic, but a True Story. A few years ago I made PCBs for a certain "well-known manufacturer of marine electrical equipment" (name withheld to protect the guilty) . A friend of mine did PCB assembly for him. One day he went to London with the owner of the aforesaid "well-known manufacturer of marine electrical equipment" to visit a large prospective customer. Arriving in Central London, he selected a nice wide pavement, and as bold as brass, parked his car on it. As he took his briefcase from the boot, my friend saw a big inverter and an angle grinder. "What's that for?" he asked. The "owner of the well-known manufacturer of marine electrical equipment" replied casually "For the wheel clamps". I tell you, the man has class....

Thanks for pointing out that absurd claim, Chris. Gave me a good laugh. Really? I suspect that the toilet often suffers from the same problem as "Co-Director Tony Martin" - it's full of sh*t. Paul

So I guess the answer to Tusses' original question (remember that?) is "No", then. Pity. I was rather hoping that it would be "42". Paul

An interesting surge supression IC. http://www.automotivedesignline.com/howto/205101011 As they say in the article, something similar could be built in discretes as a "front end" to the regulator design I posted earlier. Over to you, Gibbo - are we getting anywhere near?

I was just using my boat as an example. I didn't say that it was typical. I don't have a TV or DVD player. All my lights are fluorescent. So, in your example, that just leaves the water pump! Anyway, I think I need to "agree to disagree" with you at this point as I am sure everyone else is getting bored by this exchange. Feel free to have that last word if you feel the need. Cheers Paul G

How about this one, folks? http://www.drbob.net/project/powersupply/l...xd/default.html 12V regulated supply. Uses a LM336 reference diode and a LM324 op-amp to drive a P-channel mosfet as the pass transistor, so it's very low dropout with low power dissipation. The mosfet is rated at 6.80 A, so it should be fine for running a few LED's.

On my boat I would only draw 20A intermittently (when a pump is running for example). So whether 20A is a high load or not depends on individual circumstances. In my case, 20A would be a high load. Funnily enough, that's exactly what I said. So at least we agree on something! There's a big difference between theory and practice, however, and I suspect that there are a lot of boats out there with under specified wiring. After all, it saves the builder a few quid and who's to know? Put a meter on your tunnel light and you'll probably see what I mean. So you had to double the load to try to prove your point? Just run the sums under a 5A load (which is just as likely a scenario as 2 X 20A) and see what you get. So you just can't say that drops due to internal battery resistance is "more significant". Sometimes it is, sometimes it isn't, so you should take both into account. Have a nice day Paul G.

Sweeping statement indeed! It depends on whether high load conditions are "usual". Cable drop is always present. Even using the correct cable, 0.2 volts would not be unusual, 0.5 volts on some circuits on older boats where the cables were less well specified.

I wasn't really suggesting that it was the only component you would need, but with some transient protection I think it could be used to build a basic low-cost circuit to protect some LED lights, for example.

12.5 volts is the supply voltage to the device, and of course in the real world, you would need to take account of voltage drop on the supply cables etc. This applies equally to your beloved 78XX! However, what the OP actually asked about was overvoltage protection for sensitive devices.

At risk of getting caught in the electronic crossfire between Chris W and Gibbo, I'd suggest using a "low dropout" regulator, LM2940 or similar. These should work ok down to about 12.5 volts, or when the battery is about 40% charged (or 60% discharged, depending on your outlook on life!). I think the original question was about protecting equipment from overvoltage, so I think this would do the trick.

Marina construction pictures and "how they filled it" here:- http://www.gloucesterdocks.me.uk/canal/saulmarina.htm#Canal

I don't think it's really "new thinking", more a return to old-fashioned common sense. Back in the 1970's, I remember letting the fire officer in to inspect a sailing club I belong to. He had a good poke about the fire exits and pronounced himself mostly satisfied. I commented that he had not checked the fire extinguishers (which we had just had serviced at some expense). He replied that it was a wooden building, and, in the event of fire, he didn't want people "b*ggering about with fire extinguishers", he wanted them safely out of the place. Since these enlightened times, of course, his successors have at various times insisted on the club providing lots of extra fire extinguishers of different types in various pretty colours, then replacing these with all-red ones, and then installing an electronic fire alarm system, all of which would be at best useless in the event of a fire. However, I do think that boats are different due to the confined space. I'm always happier having a fire extinguisher to hand.

Kinda proves my point, then, if it won't do both? Seriously, I'd consider replacing it with a decent starter battey. BTW, I've never understood why such large capacity starter batteries are fitted in narrowboats. I use a good quality 50AH wet battery with loads of cold cranking amps, and it works fine. If a similar battery starts the 2-litre turbodiesel engine in my car, why should I need a bigger capacity for a 1300 cc narrowboat engine? (Puts on steel helmet and waits for incoming)

It's the wrong type of battery for leisure use. To quote from Sterling's FAQ's: "...for starting you have a large surface area of thin plates, for traction you have a small surface area of thicker plates. One is black and one is white, there is no grey area. So, if you are purchasing a battery and it has a cold cranking rating and the salesman says it is a deep cycle battery, but will also start your engine; then it is in fact a starter battery." http://www.sterling-power.com/support-faq-2.htm