2 questions 1 electickery 1 Nene and Cam navigation

[back to the boats]

Brain picking: 240v down to (12v 60w) gives 5amp)) is that 200w at
240v or still 60w??
2: Looking to go on the Nene and Cam (50ft drain and old bedford) is
there any Nicholson or similar guides out there??

[Brian on Harnser]

back to the boats was thinking very hard :

> Brain picking: 240v down to (12v 60w) gives 5amp)) is that 200w at
> 240v or still 60w??

I don't quite understand your numbers
60 watts at 12 volts is 5 amps
60 watts at 240 volts is 0.25 amps
The power is the same

> 2: Looking to go on the Nene and Cam (50ft drain and old bedford) is
> there any Nicholson or similar guides out there??

Imray do guides for Nene and Ouse, Lot of information on Middle Level
web site
http://www.middlelevel.gov.uk/

Worth joining GOA for the moorings

--
Brian traveling on Harnser
http://nbharnser.blogspot.com/

[Nick]

back to the boats <victor...@tiscali.co.uk> writes:

> Brain picking: 240v down to (12v 60w) gives 5amp)) is that 200w at
> 240v or still 60w??

No, the power taken is the VxA at any one place in the system.
Otherwise there'd be no point in transmitting electricity at 125kV (the
idea here is that loss is proportional to current, so increasing the
voltage drops the current).

So if you are getting 60W out of something at 12V you have 5A there.
You're probably taking just a bit more than 60W because of losses in the
conversion, but hopefully still less than, say, 70W.

> 2: Looking to go on the Nene and Cam (50ft drain and old bedford) is
> there any Nicholson or similar guides out there??

Only a pile of Imray things - not bad but a bit lacking in text. Of
course, there's always something mentioned down there vvvv
--
Online waterways route planner: http://canalplan.org.uk
development version: http://canalplan.eu

[Tony Brooks]

"back to the boats" <victor...@tiscali.co.uk> wrote in message
news:8187bddc-0a26-420e...@f16g2000yqm.googlegroups.com...

1. If the "thing" is inverter driven divide the unit's wattage by 10 (12v
bpoat) or 20 (24 volt boat) for the amperage draw. This "builds in " an 80%
inverter efficiency which may be a bit much for a good quality one but it
errs on the safe side.

If this is (say) a laptop drawing a nominal 60 watts at 12v but you want to
know how much it will draw from the mains then, ignoring inefficiencies in
whatever conversions are going on, 60 divided by 240 = 0.25 watt.

2. Afraid I can not help but feel sure one of the Nichs covers the Fens.

--
Tony Brooks

www.TB-Training.co.uk
Electrical & Mechanical Training
for ordinary boaters.

[Simon Kelley]

back to the boats wrote:
> 2: Looking to go on the Nene and Cam (50ft drain and old bedford) is
> there any Nicholson or similar guides out there??

The EA do large fold-out maps, one for the Nene and one for the
Ouse/Cam, which are very good, and also free.

Simon.

[Neil Arlidge]

back to the boats wrote:

> there any Nicholson or similar guides out there??

As other have said there is the OK IMRAY guides to the:

Fenland Waterways
https://www.iwashop.com/ecommerce/proddetail.asp?prod=IM21

Great Ouse
https://www.iwashop.com/ecommerce/proddetail.asp?prod=IM02

Nene
https://www.iwashop.com/ecommerce/proddetail.asp?prod=IM03

But for lovers of Nicholson's...

Nicholsons / OS used to do a guide to the Broads and Fens
ISBN 0-905522-97-4
SH copies are about, but are rare
http://www.abebooks.co.uk/servlet/BookDetailsPL?bi=1477286417&searchurl=isbn%3D9780905522975%26ltrec%3Dt

--
Neil Arlidge
NB Earnest
TNC http://www.tuesdaynightclub.co.uk/tour.html

[back to the boats]

On 16 Nov, 00:13, Brian on Harnser <br...@notharnser.info> wrote:
> back to the boats was thinking very hard :> Brain picking: 240v down to (12v 60w) gives 5amp)) is that 200w at
> > 240v or still 60w??
>
> I don't quite understand your numbers
> 60 watts at 12 volts is 5 amps
> 60 watts at 240 volts is 0.25 amps
> The power is the same
>
> > 2: Looking to go on the Nene and Cam (50ft drain and old bedford) is
> > there any Nicholson or similar guides out there??
>
> Imray do guides for Nene and Ouse, Lot of information on Middle Level

> web sitehttp://www.middlelevel.gov.uk/

>
> Worth joining GOA for the moorings
>
> --
> Brian traveling on Harnser
>  http://nbharnser.blogspot.com/

it was the 5 amp that puzzled me. the transformer on the new lights
took 240v down to 12v and the 12v halogen bulbs are 60w.

[Allan]

"Tony Brooks" <To...@tb-training.co.uk> wrote in message
news:Kd2dnSfA1fPiipzW...@bt.com...

I think your last sentence should have finished as "60 divided by 240 = 0.25
amps"

--
Allan Jones - N/B 'Keeping Up'
www.keeping-up.co.uk

[Tony Brooks]

"Allan" <sot17...@yahoo.co.uk> wrote in message
news:Jpudnfv539oE9JzW...@bt.com...

Yes - wlll spotted

TB

[Brian on Harnser]

back to the boats expressed precisely :

>
> it was the 5 amp that puzzled me. the transformer on the new lights
> took 240v down to 12v and the 12v halogen bulbs are 60w.

Are you using the transformer on the boat?