OT : generating 240v AC...?

A friend of mine used to drive one, said it was hard to keep to the speed limits if you weren't careful, it was such a sluggish little car but with variomatic gears the speed would slowly creep upwards until it could almost overtake a glacier!

300TDi defender, 15MPH to 85MPH, in fifth, not too shabby for a 13 year old truck ;-)

A bigger diameter wheel is what you want. It all depends on the size of the buckets. With enough flow, you can't put any more water in a bucket than to fill it, so the weight of water averages out the same on one side of the wheel and the torque which drives the generator remains constant so with a constant load the speed and therefore the frequency of the a c supply will be constant once it's been set up. But, as someone has already said, why bother with electrics when you can pump the water mechanically, variations in speed wouldn't be critical then.

Martin

I have, their magnetic circuits are bloody awful, so the alternator's efficiency is nowhere near as good as it could be. I wonder what the rectifier losses are like ?

Steve

Have a look at:

On or around Fri, 25 Jan 2008 22:15:10 -0000, "Rich B" enlightened us thusly:

this is (almost) true.

what happened to Ford's CVT using the flexible steel belt?

Mind, got one of these

to try, and it's dead impressive. Provided it can be scaled to handle more power, it'd be impressive in a motor.

I've never measured the % of output that a field coil would consume but in theory the pm field would be more efficient, I'm assuming that given the same rate of cutting flux this would be the only difference. I did once compare two different alternators, our asynchronous capacitive excited one and an indian pm one. On the manufacturers claims it looked like the pm one paid back at ~3 years constant running.

AJH

OK this increases torque

OK

Not so because the wheel can move before the bucket fills if there is no load from the generator.

As I said I don't think this is so unless the buckets fill to exactly the same amount each time, without a water flow control this is achieved by allowing water to overspill, wasting power.

As the early responders said the easiest way is to use a alternator to charge a battery which effectively buffers out short term changes in load. Doing it this way with some load management you could run in parallel with the grid, legally with no interconnects, and make a small contribution to electricity usage. I'm pretty certain that on the But, as someone has already said, why

It looks like it's just a play thing.

They were very successful racing -winning the driving in reverse championship every time.

Really? I had one - it would beat anything away from the line. I can only assume his/hers wasn't working correctly.

In message , Austin Shackles writes

That was the problem. The steel backed belts were an attempt to improve things and transmit more power.

In message , AJH writes

I think IIRC the OP just wants to run a pump and provide some heating to his domestic hot water - no interconnection with mains supply.

I would have thought to do that he would need about 60watts(??) for the pump and say minimum of 500w for SUPPLEMENTARY heating to his domestic hot water. Obviously every transition stage involves a loss of power so he probably needs close to 1kw

An immersion heater is a passive load so frequency control is not important, over voltage could be. I don't know if you can get a 500w immersion heater, if not might like to consider running a larger one at

110v.

If he is determined not to go down the 12v route, then how about running an alternator with rectifier to give stable 24V supply which then drives a DC/AC motor alternator set. Setting up speed control on the DC motor would then be relatively easy.

Thinking of this has made me realise just how much I've forgotten over the past forty years so no doubt there'll be all sorts of reason why it can't be done.

Possibly, it was his granny's and his only other driving experience at the time was a 350cc bike, this was all way back when I wasn't long out of school.

On or around Sat, 26 Jan 2008 18:11:16 +0000, hugh enlightened us thusly:

The nuvinci has a cunning system which has zero mechanical contact. At bicycle power levels, it works very well.

?? Zero mechanical contact? What is it, antigravity?

I saw that, is there something special about the oil that makes it act that way? It struck me the narrow bands on the spheres that had to transmit the torque was limiting.

AJH

On or around Sun, 27 Jan 2008 11:03:38 +0000, AJH enlightened us thusly:

it uses clever oil, yes. It's not entirely true that there's no mechanical contact, but there's no metal-to-metal contact. The oil is drawn into a very narrow gap between driven and driving parts and when compressed thusly goes solid momentarily, transmitting the drive. A soon as the pressure eases, it's back to liquid again.

You can experience this: get a small amount of cornflour on a plate and mix with a very little cold water. You can get a thickish liquid, about like golden syrup or treacle, which will flow slowly, but if you put your finger ins it and move fast, i.e. increase the shear rate in the fluid, it goes solid and you can pick it up, but as soon as you stop applying the right pressure to it, it goes liquid again and runs through your fingers.

In theory, it can be scaled by the addition of more (or larger, or both) balls - each ball being capable of transmitting a certain amount of torque. I doubt they're only interested in bicycles, but bicycles are a good proving ground for the principle.

Rheo-pectic materials. We test them. And they're bastards. Even cleverer are the electro rheo fluids and the magneto-rheo fluids, which would make very cunning drives too...

Steve

I noticed ferrofluid (in a strong field) being used in a TV commercial recently (Toshiba, IIRC), the implication being it was something quasi-magical they had invented.

Regards,

Simonm.