Author Topic: My Turbines  (Read 10753 times)

bogstandard

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My Turbines
« on: November 19, 2008, 05:30:00 PM »
Over the last year I have knocked up a couple of turbines as well as a few other bits and pieces.

I am showing these again because I never really had enough air volume to get them on the boil before now.

So Ralph poked me with a pointy stick, and I knocked up a quickie engine run vid to show you the engines running how they should.


http://uk.youtube.com/watch?v=Amm89H65IFo

Bogs

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Re: My Turbines
« Reply #1 on: November 19, 2008, 07:21:43 PM »
That's pretty funny John..... I've only heard that tune in a monty python song before!!!

The turbines sound good to me too  :headbang:   :thumbup:  Better that I poked you with that stick than this....  :wack:   ;D



Pity about the lights!!! A bit of voltage measurement and re-calculating to do ehh?!

Good to see you having some fun in the workshop again too... It won't be long before you can start making some of those tools and then who knows...??


Thanks for the vid,


Ralph.
I know what I know and need to know more!!!

bogstandard

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Re: My Turbines
« Reply #2 on: November 20, 2008, 01:14:25 AM »
Ralph,

That is an early Gracie Fields track, same sort of era as George formby. Then along came Vera Lynn and turned everything sombre.

I am trying hard to get my shop going again, but when I do, things will really brighten up again.

It is not like me to miss something like the over voltage,  :zap:but these things are sent to try us.

Bogs

Offline PTsideshow

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Re: My Turbines
« Reply #3 on: November 20, 2008, 01:18:18 PM »
Very nicely done, the sound traclk reminded me of some old British radio show for the wars years that are on the web for down loading will have to hunt up the bookmark and post it.
They are playing pythons spam clip on the news channel, for the story on sales of spam increasing :bugeye:
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Offline Bernd

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Re: My Turbines
« Reply #4 on: November 20, 2008, 01:42:07 PM »
Nice to see you playing around again Bog's. So you had a bit of over voltage.  :zap: Might need to add a nother bulb or two then. Wonder what the frequency is at speed. I remember that second one from that build you did on HMEM.

Bernd
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bogstandard

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Re: My Turbines
« Reply #5 on: November 20, 2008, 02:17:03 PM »
Bernd,

On original runups from before I had just over 14 volts max, so 5 3.3volt led's were perfect.

Looks like I will have to remeasure and find out the safe min quantity, then make a new holder.

John

Offline Darren

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Re: My Turbines
« Reply #6 on: November 20, 2008, 02:18:02 PM »
You could use an inline resistor John, to share the voltage with the LEDs a bit. Take the load off them a little.

be easier than adding another LED or two.

Darren
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bogstandard

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Re: My Turbines
« Reply #7 on: November 20, 2008, 05:14:53 PM »
Darren,

The LED's are in fact assembled into a solid block with epoxy. So it is easier to make a new holder rather than try to rescue this one. The more lights, the better. :zap:

John

Offline Darren

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Re: My Turbines
« Reply #8 on: November 21, 2008, 12:53:41 AM »
OK, I see your point there John, rescuing could get a bit messy then.

Darren
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bogstandard

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Re: My Turbines
« Reply #9 on: January 01, 2009, 07:07:12 AM »
Dragging this one back again.

For future reference, how would I go about making a lighting block that only lit the lights as the votage got higher. So say the first one came on at say 6v, the second at 8v etc, and when it reached say a max of 20v sound a buzzer that will warn me to start slowing it down.

Wiggly amps and electric string are not my strong points, I basically understand things, so please, no words longer than three syllables.

Bogs

Offline John-Som

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Re: My Turbines
« Reply #10 on: January 01, 2009, 10:16:28 AM »
If I were you John I would definitely wear wellies and stand on a rubber mat next time you take it to max revs. On the other hand you could consider selling the surplus back to the national grid ?

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bogstandard

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Re: My Turbines
« Reply #11 on: January 01, 2009, 06:26:32 PM »
John,

Selling back to the national grid mmmmmmmmm, don't know about that, 240 volts running a 2HP compressor = ££££'s against mini turbine giving out about 24v DC = naff all, sums don't quite add up. Maybe I could patent it as a super ungreen machine.

Reminds me of another type of machine - The Irishman.






A simple machine for turning Guinness into urine.



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Offline Chris_b

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Re: My Turbines
« Reply #12 on: January 18, 2009, 05:24:58 AM »
Re your leds...

If you're happy to have a separate battery involved (eg a PP3), then there's a magic chip the LM3914 that will measure a voltage and switch on up to 10 leds as the voltage rises (could also do the buzzer). Maplin say they keep them in their shops and you could solder it on to a scrap of veroboard and have the whole thing done in an hour. I could scribble you a circuit if you give me a bit more detail on the number of leds and the range of voltages that your turbo-generators produce

If you want the only source of power to be the generator then it's a bit harder. As Darren correctly observes, you need resistors to limit the current. Also some other trickery to make the leds come on as the voltage rises. Easiest would be to put a resistor and a zener diode (which is a special diode that require a set voltage across it before it starts to pass current) in series with each led. You can get zeners with a range of turn-on voltages, though they aren't in nice steps and Maplin don't sell them.

So the LM3914 route is probably best, not least because you can easily change the range it works over. What do you think?

Chris

bogstandard

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Re: My Turbines
« Reply #13 on: January 18, 2009, 06:09:42 AM »
Chris,

For my way of thinking, a battery would not be acceptable. I am trying to physically show what is being generated not a measurement of it.

I think I might go for small incandescents in series, they can start off dim and grow brighter as it comes up to speed. As you know LED's also have a slight voltage range, a much smaller range than incandescent, and that is how I did it last time. They all started dim, and grew brighter. Just that I didn't have enough in series to cope with the extra voltage produced, and they went over their limit and committed suicide.

But please, do show us a sketch of the battery method, as I am sure Ralph is biting at the bit to see how it is done, and you never know, I might be able to be swayed in that direction.

Many thanks.

Bogs

Offline Chris_b

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Re: My Turbines
« Reply #14 on: January 18, 2009, 03:58:35 PM »
I quite agree, too much electronics can certainly spoil the simplicity. Incandescent lamps should be ok; they are a lot more forgiving. Changing led brightness is best done by varying the current through the leds not the voltage across them. That sounds strange but the relationship between voltage you apply across a led and the resulting current that flows is exponential which is why it's easy to blow them up if you're applying a voltage. Controlling the current is particularly hard in the situation you have!

I'll put a circuit together for the LM3914 and post it

Chris

bogstandard

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Re: My Turbines
« Reply #15 on: January 18, 2009, 04:02:28 PM »
Thanks Chris.

Will look forwards to seeing it.

John

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Re: My Turbines
« Reply #16 on: January 18, 2009, 06:16:28 PM »
Quote
Thanks Chris.

Will look forwards to seeing it.

John

I'll second that... I like the idea of a display that shows power output as a visual (I know a multimeter can do that but it's not as much fun for people to look at!)


I'm patiently waiting as usual  :bang:    :D



Ralph.
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