Question on SSG operation

[Farmhand]

Good job faramog, you'll be fixing batteries in no time.

Farmhand

[faramog]

Next transistor in place (TIP31C - all the store had), load fitted and with pot turned down (resistance to base circa 10 ohms), I am getting 170 rpm, a single very strong pulse per magnet with a peak of 70V and a neg of -15V. Increasing the resistance to probable 250 ohms I am getting what looks like two peaks per magnet, peak voltage the same, rmp circa 85 and a very much reduced feed current. Feed current measured using a current probe so very inaccurate as looking at AC element. Still comparison is 1.01A (max power, min resistance) down to 250ma. Real current will be a lot less and will need a proper averager.

So far: in 45 mins:
primary went from 12.32 down to 12.07 (max power) and is now climbing back past 12.17 (mmm)
Charge battery has climbed form 12.38 to 12.44 (it is a very f****d battery - abused cells, sulphated... so a good test)

Proper tests to come ... just buggering about at the mo .. all very exciting !

[blackchisel97]

Next transistor in place (TIP31C - all the store had), load fitted and with pot turned down (resistance to base circa 10 ohms), I am getting 170 rpm, a single very strong pulse per magnet with a peak of 70V and a neg of -15V. Increasing the resistance to probable 250 ohms I am getting what looks like two peaks per magnet, peak voltage the same, rmp circa 85 and a very much reduced feed current. Feed current measured using a current probe so very inaccurate as looking at AC element. Still comparison is 1.01A (max power, min resistance) down to 250ma. Real current will be a lot less and will need a proper averager.

So far: in 45 mins:
primary went from 12.32 down to 12.07 (max power) and is now climbing back past 12.17 (mmm)
Charge battery has climbed form 12.38 to 12.44 (it is a very f****d battery - abused cells, sulphated... so a good test)

Proper tests to come ... just buggering about at the mo .. all very exciting !

Way to go, good job!


Vtech

[faramog]

Had to turn the power up a tad to maintain even after a 1 ohm tune - probably more to do with the crude setup than anything.

Anyway - still running when I left for work running 10 hours. Primary 11.95, Charge 12.53, 140rpm ... scope trace looking sweet

In looking a little online some people were showing scope traces where there was a large voltage spike (which I have) and then a sort of exponential curve down of ringing (which I have). They seemed very pleased by it. Not sure I see the significance.

Anyway, the load I have in mind is probably too aggressive - basic inverter and a desk lamp of 60W. I guess the draw form a 12V would end up being about 4-5A. Since the battery is rated at 44AH, then this sort of equates to a c8 rate and I doubt the battery can cope. Need to find some mains widget that takes a lot less - maybe 15w.

As an incidental, I saw a vid where a chap took the bottom of a CD holder, so I grabbed one off the shelf, cut a hole in the lid and inverted it over the 'pin' and taped 3 magnets into the wall (centrfugal foces working to keep the magnets in place with tape rather than glue). Not the best axles a 10mm drill bit (really needed 11 so a bit of wobble). Darn thing ran at just over 900rpm !! Easy to get carried away, but on the same resistor setup ran at 680rpm. Impressive, but the bike wheel at 140rpm 16 magnets generates 2240 pulses per min, but 60rpm 3 magnets 2040. This reflected in a slightly lower charge voltage .... faster is not always better.. its about the energy density I think.

Enough prattling ... latter ...