coozer
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| posted on 21/11/09 at 07:24 PM |
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Petrol Engine Starter
Right then, I've decided to use my Suffolk petrol lawnmower thats rusting away to build a engine starter/battery charger/generator. The mower
has a 18" cut and is quite a big thing so I reckon the motor must be 1.5hp or there abouts.
I need some plans/advise/previous experience please. I know someone on here has done it before and I wonder what size alternator to use and does it
need a battery attached?
I envisage a gas bottle type trolley with the engine on the bottom driving the alternator with the tank half way up.
Whats the correct way to gear it and wire it up?
Steve
1972 V8 Jago
1980 Z750
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02GF74
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| posted on 21/11/09 at 07:42 PM |
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I know my mountfied blade is bolted to the engine so no gearing - I have no idea what rpm it runs at but wouuld be amazed if it did rpm comparable to
cars i.e. 6,000 rpm.
alternators are geared around 2:1 from the engine hence the need to know rpm of your engine.
alternator physuical size doesn't matter that much but it will be the output current of alternator; as you fit bigger alternator and draw bigger
currents, the engine will run harder and may not have enough oompf for the demand on it.
you should be able to google what kW equates to 1.5 hp so you know the max size alternator.
alternator will need 12 V to self-exciste it and I have read that they do not like being run with the output disconnected.
that is my 2p worth - google I am sure will give you better info.
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will121
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| posted on 21/11/09 at 10:38 PM |
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one thing to consider is engine/generator RPM which will dictate electrical output frequency and want to maintain a steady ish 50hz. personally would
think it easier to by a lidl/car boot package
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owelly
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| posted on 21/11/09 at 10:49 PM |
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I built a few things like you describe for my chum who has an allotment scattered with buildings with no power. Each unit had whatever engine we had,
and driving whatever alternator we could find. They all worked and could charge a battery in about half an hour. We ran the alternator at twice the
engine speed and used a voltmeter to check we were putting 13v to the battery. What actually happened was the out put was always above 10v with the
engines barely ticking over. We tweaked the throttle to make sure they wern't overcharging the batteries.
He recently went and bought a £39 genny from Makro and it's been used every day for the past 4 months.....
http://www.ppcmag.co.uk
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blakep82
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| posted on 22/11/09 at 01:32 AM |
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battery charge sounds alright. but it won't give enough current as a starter.
unless i don't really understand what you want it for, sounds like a complicated solution to a problem which doesn't really exist.
if you need a battery charger, i'd just buy one.
if you need a quick battery charger, connect it to a running car with jump leads?
chargers are cheap from halfords
booster/starter packs not so cheap, but not hugely expensive
and a generator will need some way to get 240v from 12v. or as above, you could get a genny pretty cheap these days
________________________
IVA manual link http://www.businesslink.gov.uk/bdotg/action/detail?type=RESOURCES&itemId=1081997083
don't write OT on a new thread title, you're creating the topic, everything you write is very much ON topic!
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coozer
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| posted on 29/11/09 at 05:26 PM |
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Just dismantled the mower, the engine is 2.7kw so a big alternator is required then I'm going to build a generator
Want one of these:
http://www.machinemart.co.uk/shop/product/details/6kva-3000rpm-alternator-1-phase
but, for next to nowt
1972 V8 Jago
1980 Z750
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