GMC geberators

ive charged plenty of batterys of our cheap genny never had an issue

Fatman ,I have heard the same,a bloke I know bought a GMC generator for his house boat and the TV burst into flames.

My Brother inlaw has one just for the lighting around camp and recons it the ducks gut's.

A generator for lighting around a camp!!!!! Tell him about 12v fluoros or gas lanterns or torches or moonlight. Also tell him about noise and air pollution!

I don't go around telling people to do and what not to do,
Take a chill pill.

Its a machine that makes baby food,,,, everyone knows that!!! :)

Could you run a cheap invertor off the gennie (300w DSE for about $100).

That should smooth out the voltage somewhat ??

Wouldnt recommend it, basically ignore the 12v outlet and run off the 240v.

also worth a small hole in lower part of exhaust to allow build up of burnt 2 stroke oil out, poss why a few are packing up due to build up.

Ron

oh come on Ron, it's the build up which starts to act as a silencer!

:)

I have one of the 2300W jobbies for my tank pump at home.

You are a man of wisdom Fawlty :)

Cheap small gens have their downsides (so do small expensive ones) - the GMC is OK, see my comprehensive technical report on mine about two years ago on this forum.

Mike Harding

PS. Fawlty: I think the aliens bit may be correct...?

I will agree with you both in principle as I tried all sorts of devices/appliances and only ever had trouble with the battery chargers.

Though, as I said, plug into the so called 12V outlet and watch those wet cell batteries come to life.

The 12V "charging" output is less than ideal - quite a lot less in fact but I don't know that Honda et al are much better? (anyone?).

The GMC 12V output is simply a full wave rectified output of a low voltage gen winding. On my example (and I imagine all others) it was a full return to zero waveform with about 24V peaks (iirc). When connected to the smoothing capabilities of a battery it settled down to about an 18V charging voltage.

The real world upshot of this is that batteries of a capacity less than approx. 10Ah should only be charged for about 1 to 2 hours, between 10 and 20Ah about 3 hours above 20Ah probably not more than 5 hours - in any event this charging voltage will be outside most lead acid battery specs and should be used with caution. Essentially if you don't fully understand what I'm saying don't use the 12V charging output except in an emergency (flat starting battery etc).

Mike Harding

the first one i had peed fuel out of the fuel bowl,returned it got another and it has been fantastic(about 3 years)but yes the output is all over the shop and yes it fried my battery drills charger with ease(started surging in rpm dont know why but thats what caused overvolts and hence the damage!!)but still for $120 bucks at the time i would buy another cheers Paul

Hi Mike,

"The 12V "charging" output is less than ideal - quite a lot less in fact but I don't know that Honda et al are much better? (anyone?)."

I've spent a little bit of time poking an Oscilloscope at my EU10i Honda and I tend to agree with your summary of the 12V DC. Ok, but I wouldn't risk an expensive battery on it.

This is the open circuit output if my Honda, obviously a load will change it somewhat.



Geoff

Hi Geoff

A bit smoother than the GMC but still way too high on the voltage - I imagine it drops at full load but it'll still boil small batteries. Wonder what the high frequency noise is?

Nice screen grab - what the scope? Is it one of the USB type? What specs?

Mike Harding

Hi Mike,
I don't really know what happens to the DC under load. The day I played around with the CRO and the generator I didn't have anything to load the DC side.

Oscilloscope is a Yokogawa DL1540CL. (I actually work for them in Tech. Support for PLC's, Hybrid Controllers and SCADA so I have access to the whole kit bag of unusual test gear)
This unit is an older one, it actually has a floppy drive. Its replacement uses as you suggest USB, it also has Ethernet and FTP capability.
1540CL is a 200MS/s, 150mHz, 4 channel unit with LCD.

I captured the screen to file on the internal floppy disk then opened on my PC with the software you see above.

Here's a couple from the AC side of the EU10i. My best guess is the inverter has some interaction on the output. The capture with two paralleled 10i's is interesting. They appear to "converse" over the AC bus. The reason I say that is the block diagram of the units show paralleling of the AC outputs not the actual inverter modules. How they do load sharing is an interesting one to speculate on.


Single EU10i at 575 Watts.




Paralleled EU10i at 2,000 Watts.

Note: For safety, readings where taken on the secondary side of an 240V to 24V transformer.

Geoff.

Harding, thanks for the compliment - I like your nonsactimonious approach.
I know I'm only a guest but strewth some of the sactimonious garbage some people post on here just makes me laugh....
As to the Aliens, I firmly belive their only interest in small generators is to start their Ion Drives and they must marvel at us still using a flow of electrons in a copper wire to power our breadmakers.
Actually I do enjoy laughing so the more sanctimonious garbage the better.....

Ah! good old Mr. Fawlty.

Yep! us sanctimonious eathlings have it all over those dumbarse aliens - we use that high tech substance called fire to make our bread and toast.

None of that foul poluting ion stuff for us.

And Mr Harding could you please explain why you reckon that the silly scope shows the Honda as being very 'noisy' when mine is very quiet.

It is an intrinsic part of Zen Lucy - within the noise silence is but a transitory illusion....

Ha! Ha! Ha!

You have been watching/listing to too much BONZ-a-vision.

Brother Lucy,
The noise the learned Mr Harding refers to is of an electrical nature characterised by the little squiggles on the otherwise well ordered yellow lines in my screen captures.

You are in fact both correct, your Honda is very quiet in an audiometric sense and Mr Harding is correct regarding the electrical "noise"

Hope that actually helps,

Geoff

I suspect they were hiding :)

and being their normal very quiet selves :))

I had a brief moment of hysteria when I read that too Gramps. Same guy actually invented the Faraday cage which we all know is handy to keep your gerberator free from "alien" attack......

Oh this is too good to miss......... Do you mean repalace as in the St Kilda Palaise which will have to be replaced now that some cretin set fire to it.

I'm sorry Star Bug but I must disagree.

I have (had) two TVs; one of these appliances has been connected to my GMC generator for the past hour and is still running, apparently, properly - the other I attacked with a large axe and chain saw and was able to render it totally unusable within 15 seconds!

Therefore.... a cheap gen set in _not_ the quickest way to destroy your TV!

Mike Harding

15 seconds to render a TV senseless with and axe...... you were taking your time :)

Some of these gennys work ok, some dont. When the regulation on them fail they then to take out whatever is connected to them.

And even if you have one of the big name brands, get the things serviced and checked for regulation from time to time.

I'm led to believe that the electrical components of the Honda (inverter) "gerberators" are made by the Sawafuji Electric Co Japan (the home of Engel)..
http://www.sawafuji.co.jp/english/
http://www.elemax.jp/products_shx.html
The Engel "gerberators" use Honda engines....

Take your pick;-))

Hi Ed,
If the electrics for the Honda's are made by Sawafuji then there are two grades of electrics, one for Honda and one for their own Engel units.

This line, "Waveform - Square-Wave" taken directly from the Elemax site clearly states the output of the two specified Engel models.

The Honda's are Sinusoidal output and as Elemax have publicly stated their's are Square Wave. These are big electrical differences!

It would actually be harder to make two seperate sets of electronics than just the one. This would lead me to the conclusion that Sawfuji do not make Honda's electronics.

Geoff

G'day Geoff,
No skin off my nose one way or the other;-)
Just what I've heard/read from a variety of sources, one of which is here http://www.olbis.com.au/ap_template/subcat_generators.asp
I would have thought that if a firm such as Olbis were to make such a statement publicly without being able to substantiate it, they'd be leaving themselves open to legal action (??), so I'm inclined to take it at face value:)

'ave a good'un;-))

Ed

Hi Ed,
Nor is it any skin off mine.

Just a pity people totally missed what I said about the obvious difference in the electrical-electronics side of the two units making it difficult to understand where the two are alledgedly identical.

This is totally un-related to the useful information on Engels using Honda engines.

Enjoy,

Geoff

Ok! Basil

You now have my avid serious attention and I promise not to ask any more questions about you allegedly backing off ramps with the door and in the process converting said door into a Roachie Gull wing, or embarrassing questions about doing the same to a roll-a-door.

A mercury Arc Rectifier. I have been looking for a rectiier for my arc welder for a long time without success.

Could you please tell me if these things are still available and if so where would I get one.

Ta.

Ms Lucy

Wow, what a museum piece......i haven't seen/heard of one of them since i saw one about 15 years ago when i first started my electrical apprenticeship. Walked into the old Toowoomba Electric lighting and Power company building just before being demolished only to see this huge mercury filled glass object.

I take it we are talking the same thing, albeit slightly smaller i would summise. Simiilar rectifier shown at this link

Andrew

You are dead right there.

I googled this gizmo and it is straight out of Dr. Who. (LOL)

However, not so long ago a dude in NSW had got hold of some old stick welders from a Tech School disposal sale.

Apparently MIG & TIG had rendered same obsolete. (Yes I know there is a big difference between MIG & TIG)

Anyway, these small portable stick welders were AC but had a 'doover-lackey' (small thing) somewhere in the front of them that was a Rectifier/converter or such like and turned them into DC somehow.

I missed the deal/bid on all six of them which peed me off no end.

Do any of you electronic smarty pants know where I could source one of these and not the Dr. Who monstrosity.

Mine is an incy wincy one, measures around 400mm cube, it's in a perforated steel box. Yes it is a museum piece and I doubt that you could get one today. I got it from White bay power station in Sydney in the early 60's . Told it was out of a Trolley bus but I have doubts. Looks spectacular fired up....
You can buy rectifiers specifically for attachment to welders from most welding suppliers but take a big purse with you they are not cheap.
Incidentally White Bay Pub has closed but reopened as a movie making venue and Fred Nile is concerned because the movies they are making there are the "wrong sort" of action movies.

How much mercury would be in that sucker?

After seeing someone trying to clean up mercury from an old thermometer.....near on impossible :-), i would hate to see these large rectifiers glass crack and leak!

A sight to be seen none-the-less when working.

Andrew