pvb
Well-Known Member
It's been available for years - called the WhisperGen.
Micro 12v Generator Project
- Thread starter mattnj
- Start date
It's been available for years - called the WhisperGen.
grumpygit
Well-Known Member
You crack on if makes you happy and remember that "necessity is the mother of inventions".
Just one point as far as the alternator goes, the revs will have to be increased considerably to get it's regulator to the correct cut-in voltage, but once it's cut-in you should be able to decrease engine speed and still have output. Not sure what output, I'm sure you will let us know this in due course. good luck.
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Just one point as far as the alternator goes, the revs will have to be increased considerably to get it's regulator to the correct cut-in voltage, but once it's cut-in you should be able to decrease engine speed and still have output. Not sure what output, I'm sure you will let us know this in due course. good luck.
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mattnj
Well-Known Member
Success!!
Mounted the alternator with the flexi coupling and ran it up yesterday.....my meter only reads 15amps and it went right off the scale straight away at a very fast idle...the mounting is very rough a ready (finishing it off now) but i though i should test the theory before spending too much time on making it look decent...
All looking good (from an output point of view) after a minute or so the ammeter came back under 15amps....battery was fully charged already so no surprise there.
Alternator does bog down and stall the engine at normal idle, but that has been easily fixed my winding the idle screw right in.
Will keep you posted, off to tidy it up a bit...
Mounted the alternator with the flexi coupling and ran it up yesterday.....my meter only reads 15amps and it went right off the scale straight away at a very fast idle...the mounting is very rough a ready (finishing it off now) but i though i should test the theory before spending too much time on making it look decent...
All looking good (from an output point of view) after a minute or so the ammeter came back under 15amps....battery was fully charged already so no surprise there.
Alternator does bog down and stall the engine at normal idle, but that has been easily fixed my winding the idle screw right in.
Will keep you posted, off to tidy it up a bit...
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nimbusgb
Well-Known Member
Would be quite easy to rig a current sensing circuit to open the throttle when demand is high and settle it back when demand goes away.
mattnj
Well-Known Member
yes, if i ever get round to it, it will have a PIC microcontroller doing all that with a servo...a project for the winter perhaps, for now, easy enough to move the lever by hand!
Once i have the electric start sorted, it will need a PIC for sure....as it will be (hopefully) auto-starting and shutting down as needed on demand.
Heckler
Well-Known Member
Oh, I didnt know they were electric start, makes life a lot easier that, if it is stuck away in the sugar scoop.
Stu
mattnj
Well-Known Member
they are not, as standard, but available as a kit.
mattnj
Well-Known Member
Trying to generate too much power...
a few more developments but run into a slight problem, when connected to flat batteries, the alternator attempts to put too much charge into the batteries and hence stalls the engine, it does actually manage if the engine is put on 80% + throttle and it outputs a load of amps (off my meter scale) but i would much prefer it to run slower, and output less, and have a bit of control, otherwise it is a right pain to manage engine speed with no output (amp) control.
How can i reduce or control the alternator output? Any ideas....
Here is a video of it running at high (80%ish) output here....thats producing over 40amps...(ignore the multimeter volt reading, its broken and over reading buy a volt or two!)
http://www.youtube.com/watch?v=0-F3Omh9Wgw
oh and by the way, i have removed the water cooled exhaust for now so it is NOISY again, but i get fed up with standing around in water whilst tinkering...that can go back on at the end.
a few more developments but run into a slight problem, when connected to flat batteries, the alternator attempts to put too much charge into the batteries and hence stalls the engine, it does actually manage if the engine is put on 80% + throttle and it outputs a load of amps (off my meter scale) but i would much prefer it to run slower, and output less, and have a bit of control, otherwise it is a right pain to manage engine speed with no output (amp) control.
How can i reduce or control the alternator output? Any ideas....
Here is a video of it running at high (80%ish) output here....thats producing over 40amps...(ignore the multimeter volt reading, its broken and over reading buy a volt or two!)
http://www.youtube.com/watch?v=0-F3Omh9Wgw
oh and by the way, i have removed the water cooled exhaust for now so it is NOISY again, but i get fed up with standing around in water whilst tinkering...that can go back on at the end.
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JohnTH
Well-Known Member
This is just the sort of empirical stuff that I like Matnj, nice one!
As has already been mentioned, machine guns used to have (could still have) water cooling. Hot water is useful.
A refinement for later on could be something to harvest this otherwise waste heat.
The debate relating to soldered exhaust fittings melting is easily fixed. Use a compression fitting up close to maximum heat before reverting to soldered items further down stream. Yes, a compression fitting is bulky but!
Sound (noise) is conventionally measured in bells. My db meter cost less than £10.00 on E Bay. It sounds better (pun) to quote numbers rather than to make subjective assessments of noise.
73s de
Johnth
As has already been mentioned, machine guns used to have (could still have) water cooling. Hot water is useful.
A refinement for later on could be something to harvest this otherwise waste heat.
The debate relating to soldered exhaust fittings melting is easily fixed. Use a compression fitting up close to maximum heat before reverting to soldered items further down stream. Yes, a compression fitting is bulky but!
Sound (noise) is conventionally measured in bells. My db meter cost less than £10.00 on E Bay. It sounds better (pun) to quote numbers rather than to make subjective assessments of noise.
73s de
Johnth
peterb
Well-Known Member
Trustee from the Toolroom
Have you ever read Nevil Shute's book, "Trustee from the Toolroom"? A major element in it is a home-designed and home-built motor-generator set, with a 7cc 4-stroke petrol engine driving a governed generator at 3000 rpm. The overall size was 4" x 2" x 2½”.
I don’t know whether Shute ever made (or even had ever seen) such a device, but he was a good engineer. And the book is worth reading just for its sailing content.
Have you ever read Nevil Shute's book, "Trustee from the Toolroom"? A major element in it is a home-designed and home-built motor-generator set, with a 7cc 4-stroke petrol engine driving a governed generator at 3000 rpm. The overall size was 4" x 2" x 2½”.
I don’t know whether Shute ever made (or even had ever seen) such a device, but he was a good engineer. And the book is worth reading just for its sailing content.
daveyw
Well-Known Member
Just a thought, if you put a dynamo on it instead of an alternator, couldn't you use it to start the engine? Maybe dynamos are less readily available.
Great project though.
Great project though.
grumpygit
Well-Known Member
Yes you could, but I doubt if it would have enough guts on direct drive, though a dynastart would. But then you are defying the project by costs.
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mattnj
Well-Known Member
no, but just ordered it off ebay for £2.76 posted!
mattnj
Well-Known Member
did look into that, but massive and heavy in comparison, the reason i chose the alternator i have is:-
a) I had it kicking about.
b) It is very light for an alternator at only 2.7kg
pcatterall
Well-Known Member
Congratulations on the work so far.
Please indulge me with this very basic question.
Why is there nothing like this on the market? Is it because the market ( for a device that just outputs 12 Dc) is not big enough?
Several forumites have suggested that a suitcase type genny is just as good but thes are constructed to supply AC and then to you need to convert back to DC. Is that where your system scores?
Keep at it!!
Please indulge me with this very basic question.
Why is there nothing like this on the market? Is it because the market ( for a device that just outputs 12 Dc) is not big enough?
Several forumites have suggested that a suitcase type genny is just as good but thes are constructed to supply AC and then to you need to convert back to DC. Is that where your system scores?
Keep at it!!
nimbusgb
Well-Known Member
Actually this project also works on AC 
That's what an alternator generates. It's just that its rectified and regulated to 12v and 40A instead of unrectified 220v and 4 to 5 Amps.
This is just a suitcase genny without the suitcase and with a slightly differently wound alternator ie: more current less volts - 12v at 40 amps is roughly 500w whereas even a small commercial suitcase one is 220v at 4 to 5 amps so about 1kw or twice the power.)
Its certainly a lot safer never generating anything above 20 Volts or so especially with lots of water about. I see no reason why stripping the existing alternator out of a suitcase generator and replacing it with a 100A car type alternator would not be completely workable.
Anyone want to mail Kipor and put the idea to them? I bet they don't realise what kind of market they are turning their noses up at! I would hazard a guess that with the rapidly developing alternative energy market a generator that is more compatible with the output of solar panels, small wind gennerators and with current low cost batteries could actually be a nice little earner!
That's what an alternator generates. It's just that its rectified and regulated to 12v and 40A instead of unrectified 220v and 4 to 5 Amps.This is just a suitcase genny without the suitcase and with a slightly differently wound alternator
ie: more current less volts - 12v at 40 amps is roughly 500w whereas even a small commercial suitcase one is 220v at 4 to 5 amps so about 1kw or twice the power.)Its certainly a lot safer never generating anything above 20 Volts or so especially with lots of water about. I see no reason why stripping the existing alternator out of a suitcase generator and replacing it with a 100A car type alternator would not be completely workable.
Anyone want to mail Kipor and put the idea to them? I bet they don't realise what kind of market they are turning their noses up at! I would hazard a guess that with the rapidly developing alternative energy market a generator that is more compatible with the output of solar panels, small wind gennerators and with current low cost batteries could actually be a nice little earner!
A
Alcyone
Guest
Stu:
What's the noise rating for your SDMO? I googled them and found 71db, a lot louder than(say) the EU10i at 52db.
Mattnj: Keep at it. it's interesting to read, even if you end up scrapping the thing. It's a great thing to do and the very least you will do is learn loads. Thanks for posting this.
KevB
Well-Known Member
mattnj
Well-Known Member
update.....found a breakers yard, with a 40amp version of the 55amp alternator i am using...so bought that for £30, hopefully will fix the bogging down issue and stalling at slower revs....turns out they are standard fit on a 900cc, daihatsu hi-jet !
output figures of current (55amp) and new (40amp) units:-
40amp
3000 - 10.8amps
4600 - 35.8amps
6200 - 45.1amps
55amp
1540 - 16.8 amps
3000 - 48.9 amps
4100 - 54.1 amps
6100 - 60.5 amps
Lets see if that fixes the stalling issue..
output figures of current (55amp) and new (40amp) units:-
40amp
3000 - 10.8amps
4600 - 35.8amps
6200 - 45.1amps
55amp
1540 - 16.8 amps
3000 - 48.9 amps
4100 - 54.1 amps
6100 - 60.5 amps
Lets see if that fixes the stalling issue..
Jenaline IV
Well-Known Member
Wow! What a fantastic little project. I have a little dinghy that uses an electric motor for propulsion. On 2 80AH batteries I get about 4-6 hours of motoring which for fishing is fine. I cant do more than one day at a time because I have to recharge. I thought about something like this about 18 months ago and it was poo pooed despite my arguments that it would be beneficial as I could recharge the batteries in a couple of hours as opposed to running an engine for 4-6 but heyho.....
.... I would love to have a look into this myself probably next year. I especially like the idea of electric starting.
.... I would love to have a look into this myself probably next year. I especially like the idea of electric starting.