SG8-kit typical amp draw consumption?

[MrRonsen]

Hello,

i have built the SG8 kit... is ready and running

here my SG8-kit in action...
http://rgey.de/wp/?page_id=950

what is the suggested typical primary amp draw with a SG8-Kit?

- 1,6 Amps drawing
- using the 10watt 12 ohm trigger
- attraction mode..
- everything keeps cool...
- 22inch wheel, 24 mags,
- 205 RPM at input of 1.6 Amps by 12.0-12.3 V

I think the primary amp draw is too high...
should i make the distance between Coil and Magnet wider..
so that induced trigger current will come down..
or should i keep the coil close as possible and add a potentionmeter into the trigger wire?

We want drive attraction mode.
But the core of the coil is stronlgy attractive to the magnets itself, already without powering coil.
So keep the coil more millimeters away
until the magnetic lock isnt there anymore/or less strong.?
And the trigger does still trigger..
then the powered coil will do the attraction...

going in which direction ?

[D Rhodes]

I think you answered your own question. I am running my 5filar coil (18#&20#) with a 16mm gap. It reaches 1 pulse at about 500mA Draw. Experiment with the Gap if you can. Build an adjustable air gap capacity into your machine if you are able to. Being able to change the air gap as the wheel is running will give surprising tuning ability.
I read somewhere that if you take a screwdriver and pass it over the rotor magnet you use, the point at which the magnetic field affects the screwdriver is the gap you can start with.
Previous to reading that, I always used a 1/8th inch gap...draw was always high. Try the wider gap and see what happens.
Change one thing at a time so you can see the effects before changing another thing.
My 2 cents worth!
Dennis

[John_Koorn]

The first thing I would do is check the free spin time. Make sure the wheel is balanced horizontally and vertically.

He who has the longest free spin time wins

John K.

[MrRonsen]

the free spinning time of my wheel is 7 minutes 30 seconds... till 8 minutes...

some balancing is still possible..


i use bicycle quick clamping system,
i tried ceramic bearings and bearing holders.. but this was too complicated,
difficult to adjust the bearings straight precise along the main axis.. ended with less free spinning time than before..
so i stay with the standard bicycle bearings..
like this
https://encrypted-tbn1.gstatic.com/i...SXSYKcYDzBpjDA
http://www.zeg.com/online-shop/produ...-guenstig.html
http://www.zeg.com/online-shop/produ...tml?dbStart=84

maybe anytime standard mountain bike nabe with industrial bearings
http://www.zeg.com/online-shop/produ...-guenstig.html

but i think i have to concentrate on other things to get the amp-draw down...
till now i use the standard sg8-kit version, untuned ...
and till now did not got an answer about what the typical amp draw of this kit normaly is...

[Branch Gordon]

Hey MrRonsen,

It looks like from the photo of the bearing you are using that they have a separator between the balls? I didn't have good results with that kind. I was able to get over 11 minutes from just standard loose ball bearings. I dumped the steel ones out, measured them with calipers, and then bought the equivalent size ceramic loose ball bearings. Lubed those up with Tri-Flow (also removed all the remaining grease from the wheel). I also loosened the nut that holds the bearings in place so that it wasn't a tight fit over the bearings anymore. Too loose and your wheel becomes wobbly.

My two cents...I worked on this for about a month before getting it right.

Probably doesn't help you much, but my 4 transistor kit pulls about 620mA when tuned to max RPM.

the free spinning time of my wheel is 7 minutes 30 seconds... till 8 minutes...

some balancing is still possible..


i use bicycle quick clamping system,
i tried ceramic bearings and bearing holders.. but this was too complicated,
difficult to adjust the bearings straight precise along the main axis.. ended with less free spinning time than before..
so i stay with the standard bicycle bearings..
like this
https://encrypted-tbn1.gstatic.com/i...SXSYKcYDzBpjDA
http://www.zeg.com/online-shop/produ...-guenstig.html
http://www.zeg.com/online-shop/produ...tml?dbStart=84

maybe anytime standard mountain bike nabe with industrial bearings
http://www.zeg.com/online-shop/produ...-guenstig.html

but i think i have to concentrate on other things to get the amp-draw down...
till now i use the standard sg8-kit version, untuned ...
and till now did not got an answer about what the typical amp draw of this kit normaly is...

[Tom C]

Ronny,

There is not a TYPICAL amp draw, just too many variables.... you can expect between 1 and 2 amps depending upon the number of magnets and other variables. a 21 magnet wheel will do between 1.5 and 2 amps with the 12 ohm resistor installed. depends upon coil gap, magnet strength, battery wire size, battery capacity, battery type, battery condition, how your magnets are mounted (yours is unique) freewheel time, etc.... you are in the ballpark, there is no set amount it should be as long as you are getting good charging.

Tom C

[MrRonsen]

back from the basement

i added a 1k 4watt potentiometer,
in addition to the 12 ohm resistor,
at the trigger and tuned to
- 1.1A at 199/202 RPM
instead of previous
- 1.8A at 195/200 RPM

so thats better/good value..

ok, i am in the ballpark..
and 1.1A and 1.8A are big difference to me...
the primary will do work longer before need to recharge


PS: i have used a analog Ammeter and digital clamping ammeter..
they show both "same" values..
over range from/till..
so i am happy that i can use the clamping ammeter
instead of fiddle in/out the analog ammeter in line.. putting resistance in too..

[George]

MrRonsen. I have also purchased the SG8 kit and have it going without problems. I have used a 25.5" rim to rim steel bike wheel with 23 ceramics spaced 2.75"apart. Have used a .375"threaded shaft and two self aligning ball bearings. with 5mm coil to magnet spacing and using the optional resistor. First results with 1.8 amp. draw wheel speed 265rpm.output .700amp With 10mm spacing results in 1.1amp draw and .500 output . Free spin time 9min. As has been mentioned before there is significant variation in the results with different battery impedences.
Will post pictures when I work out how to do it. Comments to improve appreciated. George.

[MrRonsen]

@George: "self aligning ball bearings" sounds interesting...
like these:
http://www.skf.com/group/products/be...ngs/index.html