Hypothetical 48 volt system (not Hypercritical...)

[dmr]

If and when the automotive industry goes to 48v, and there are lots and lots of 48v bits and pieces available cheaply, then it might might sense for boats too.

USB-C could be a factor in this as the 12 sockets we use now will all become USB-C.

 

48v was chosen to be below the 50v threshold so I also don't know how the charging at more than 48 fits into this. Is the threshold really 50 or is it 60 ?

 

The 48v idea has been around for years and about 20 years ago I sat in a meeting and was told that within 5 to 10 years all vehicles would be 48v. It didn't happen but with growth in hybrids could maybe happen now.

 

Part of the 48 dream was that the the engine would reduce to just crank, rods and pistons. Oil and water pump would be 48v electric and run when needed to save fuel. Valves would be solenoid controlled for precise variable valve timing. Camshafts would be history.

 

I envisage a nice old Russell Newbery modified to have solenoid valves with those solenoids built from exposed varnished copper wire on turned paxolin formers, it would look great.

 

...............Dave

[ditchcrawler]

If and when the automotive industry goes to 48v, and there are lots and lots of 48v bits and pieces available cheaply, then it might might sense for boats too.

USB-C could be a factor in this as the 12 sockets we use now will all become USB-C.

 

48v was chosen to be below the 50v threshold so I also don't know how the charging at more than 48 fits into this. Is the threshold really 50 or is it 60 ?

 

The 48v idea has been around for years and about 20 years ago I sat in a meeting and was told that within 5 to 10 years all vehicles would be 48v. It didn't happen but with growth in hybrids could maybe happen now.

 

Part of the 48 dream was that the the engine would reduce to just crank, rods and pistons. Oil and water pump would be 48v electric and run when needed to save fuel. Valves would be solenoid controlled for precise variable valve timing. Camshafts would be history.

 

I envisage a nice old Russell Newbery modified to have solenoid valves with those solenoids built from exposed varnished copper wire on turned paxolin formers, it would look great.

 

...............Dave

It was also said that alternators would be oil filled and built into the engine, but that didn't happen.

[WotEver]

This was going to be the big thing in automotive and re-appears every few years. Most systems are now either 12V DC or > 300V DC.

With >300V AC motors!

 

I envisage a nice old Russell Newbery modified to have solenoid valves with those solenoids built from exposed varnished copper wire on turned paxolin formers, it would look great.

And we could have exciting new topics such as "Cracked Paxolin Former" 'Can i form a new one out of Bakelite?'

[stegra]

I think a lot of wind turbines are 48v so that might be a possible source of an alternator. Using 48v and localised DC-DC converters means long cable runs can use smaller cables or suffer less voltage drop. Also, if using a lot of solar, they can be connected in series and used with an off-grid type inverter to increase efficiency. Disadvantages would be relatively high price of DC-DC converters and potentially hazardous voltages from the solar. However, most people will have potentially hazardous 'mains' voltages anyway.

[dmr]

It was also said that alternators would be oil filled and built into the engine, but that didn't happen.

 

That was the reason for my involvement, we were doing a sort of look to the future to identify threats and opportunities type thing and the company I was working with were making clever belt and pulley type stuff so built in alternators were a serious threat.

 

Turned out that getting sold to an American investment house who shut down the entire engineering dept. was the bigger threat that we failed to predict.

 

.................Dave

Edited January 30, 2017 by dmr

[Robbo]

However, most people will have potentially hazardous 'mains' voltages anyway.

DC high voltages are more unsafe than AC tho.

[dmr]

With >300V AC motors!

 

And we could have exciting new topics such as "Cracked Paxolin Former" 'Can i form a new one out of Bakelite?'

 

I have pondered what the trad engine boaters will do if we are forced to go electric in the future, but looking at some of the steam punk stuff around of late there is huge potential. Could be quite exciting.

 

................Dave

[stegra]

DC high voltages are more unsafe than AC tho.

 

Ah. Ok. I'll just go and lick busbar on the house CU. My point was that precautions are already being taken for high voltage circuits so it's another one to be cautious about. In reality the high voltage from a series solar set-up would be only from the panels to the inverter rather than spread around the boat.

[Robbo]

 

Ah. Ok. I'll just go and lick busbar on the house CU. My point was that precautions are already being taken for high voltage circuits so it's another one to be cautious about. In reality the high voltage from a series solar set-up would be only from the panels to the inverter rather than spread around the boat.

As long as you lick the neutral or earth busbar then you'll be okay.

 

With AC high voltage if you touch the live will throw you off, where DC your muscles will contract and potentially grab the thing thats live.

[FadeToScarlet]

Why does your thread title say "Hypercritical"?!

No it doesn't

[MtB]

As long as you lick the neutral or earth busbar then you'll be okay.

 

With AC high voltage if you touch the live will throw you off, where DC your muscles will contract and potentially grab the thing thats live.

 

 

That's not quite what happens as I understand it.

 

With AC you get 100 chances a second to let go as the voltage passes through zero, while DC makes your muscles spasm and you stay gripped on.

 

I'd prefer to get a 240Vac shock than a 60Vdc...

[MtB]

 

I have pondered what the trad engine boaters will do if we are forced to go electric in the future, but looking at some of the steam punk stuff around of late there is huge potential. Could be quite exciting.

 

................Dave

 

 

I have to say when I visited the steam punk exhibition at the Museum of the History of Science at Oxford seven or eight years ago the "Eye Pod" made by Dr Grymm was the highlight of the day. And pleased to say I actually met the chap!

 

 

 

Loads of other amazing work, much of which was at the same exhibition, here:

 

https://uk.pinterest.com/pin/53339576808645847/

[Robbo]

 

 

That's not quite what happens as I understand it.

 

With AC you get 100 chances a second to let go as the voltage passes through zero, while DC makes your muscles spasm and you stay gripped on.

 

I'd prefer to get a 240Vac shock than a 60Vdc...

AC is more likely to stop the heart tho, if you have a DC shock the heart is more likely to start beating again once the current is removed.

 

Problem with DC is that most people believe wrongly that it's safe so don't treat it with same respect.

[I Spartacus]

You can get a 48v alternator such as the powercore there a few out there, But I would like to have a back up 48v generator just in case, you would run the geny when using big loads.