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Re: Electrical system for boat

Posted: Fri Jan 03, 2020 10:04 pm
by Titan
Lopez Mike wrote:
Fri Jan 03, 2020 3:41 pm
Consider a radio controlled vehicle servo.

They are relatively inexpensive, available in a wide range of sizes and torque ratings and easily interfaced with a small dedicated micro controller. This has already been done and is mostly a 'turnkey' solution. I've done so with a little controller called a Basic Stamp but there are others. The Stamp is just easier to program and there are programs already written and available.

You biggest problem then will be to contrive a suitable throttle valve. A non-trivial problem.

I try not to "Invent the Wheel" more often than I need to.
That is pretty much exactly what I am doing. Almost all the bits are cheap off the shelf items.

Re: Electrical system for boat

Posted: Sat Jan 04, 2020 12:26 am
by Lopez Mike
I would consider carefully exactly why you are going down this path.

As Fred says, electrical lights are a good thing but with modern L.E.D.s it's hard to justify an electrical system. Plain old alkaline batteries are available everywhere. You can go crazy with search lights, nav lights and area illumination within the boat and still not come up with a need for very many amp. hours.

I understand the entertainment and intellectual joy of sorting out a system like this but hope you understand that it's not very necessary.

As a good example of illogic, I'm planning on a duplex steam driven feed water pump even though I know that it's grossly inefficient. I just want to see it running along at the dock when I don't feel like using the hand pump.

Have fun and keep us posted.

Re: Electrical system for boat

Posted: Sat Jan 04, 2020 2:02 pm
by Titan
Oh I am aware there are easier ways to do this, I am purely doing it this way because I want to, and the Stuart engine makes a nice little showpiece. I would have preferred to have the governor all mechanical and all the lights incandescent i.e. all 100 year old+ technology even if the actual items used are not that old. However some electronics seem to have inevitably crept in. My aim is to have everything on the boat powered by steam, albeit with battery back up just in case.

Re: Electrical system for boat

Posted: Sat Jan 04, 2020 5:40 pm
by RNoe
All steam powered is an admirable goal. Just to do it.

I'll use battery-powered LED running and instrument lights on my small steam launch.
'Git -er done."
I'm more interested in getting on the water. Something about running out of years...

My two steam locomotives (7-1/2" gauge) give me all the steam-only entertainment I desire.

Re: Electrical system for boat

Posted: Mon Jan 06, 2020 3:50 am
by cyberbadger
I have an electric cold filling electric pump that I need to power to fill the boiler when it is not under steam.

So far I have been pretty happy with bringing onboard a hobby 5Amphr 11.7V Lithium Polymer battery which ways less then a pound in weight.

However I got a new electric pump motor. I use Dewalt 20VMax tools, so I took a spare Dewalt charger and heavily modified it so that I can just a bring a battery or two from my Dewalt tools and plug it into this modified adapter I made and it will accept either Ryobi batteries or Dewalt 20V batteries.

However, the LED nav lights, which I have never honestly needed yet, would not probably tolerate the 20Vmax battery voltage.


Re: Electrical system for boat

Posted: Sun Feb 09, 2020 10:15 pm
by Titan
Finally built up my electronic engine governor for the generator. Surprisingly it pretty much worked as intended first go, although I did get a couple of wires on the servo controller the wrong way round due to only having instructions in Japanese... However after swapping them about and testing it on various voltages, the servo seemed to move throughout it's travel with a voltage input from 10v to 15v, with 12.5v being about half way. There are several pots on the servo controller board to fine tune it with. I have also added a large capacitor to the input to the governor, as I expect the output from the generator will be somewhat noisy, which at best would make for a chattering servo. I have tested it on an old model train controller which gives out a rough full wave rectified output, and it worked pretty smoothly on it.

Having said that, there are plenty of other variables to contend with. The throttle I intend to use with it is effectively a globe valve, so will not have a linear characteristic, and of course on top of that the supply pressure will vary depending on the requirements of the main engine. Hopefully the pots on board the servo controller, plus some judicious adjustment of the linkage between servo and throttle should give a sensible voltage range under normal operating circumstances without having to intervene.