Part of remote living I think is beating the elements, and the things that crop from them.... sometimes they are just a nuisance, and some times the trials are almost life and death.... this story falls into the latter category.... very serious.
One of the important things of course is muscle relaxants, and free radical potions designed to help lower your cholesterol.... you know what I'm talking about of course.....WINE.... acres and acres of it.
There is a small winery near Whitemark, that produces red and pinot and chardonnay.
You cant do this unless you have grapes.... bigger and juicier the better. But this year we had unseasonal warm humid periods and this of course fosters fungal growth. Downy mildew to be more precise..... so what you say.....
Well the spray unit that does this important job, started to run for short periods, and then stop... cool down and then start again... then it was erratic. It had no markings of what kind of engine it was, but it was an industrial 2 stroke... we think a solo.
Long and the short of it was it needed a new electronic ignition system, but we couldn't get one for a start, and time was important. Waiting for a unit from Europe was problematic... the grapes would suffer.... and then I would suffer.
It was a simple CDI, with a single pickup, a black box and coil pack combined, and a spark plug. There were a couple of ducati cdi units on the island, but they all required a 2 coil system..... so I decided to make my own from the ground up type of thing.
The outline was straightforward.
On the rising wave form from the one coil, we would store the output in a capacitor, and when the waveform changed direction... at a point of our choosing, we discharge it into a coil... and make a spark... simple...particularly if you say it quickly.
The scr needs to be sensitive gate, as the currents are small at startup. The first thing was to steal the battery charging coil from under the flywheel, and use that as our CDI charge coil. This unit has no battery anyway.. or lights etc. It is superfluous to requirements.
I unwound the few hundred turns of thick wire, and rewound over a thousand turns of fine wire from a microwave secondary.... and it looks like this:
Being symmetrical, we can turn it over if the pulse is negative going from the start. We want the positive waveform to charge the cap BEFORE we discharge it with the negative wavefront.
Now that was the easy part, the next bit is the circuit... which as usual now it is all over, I don't have the scribble bits that I transfer into Protel pcb maker, but it looks like this, and if you want you can draw the circuit.
CLICK TO GET A BETTER VIEW
Next was a coil from a car down at the tip (dump), and presto, a complete CDI ignition system, which if you had to, could make any single cylinder engine run at a pinch... Briggs, Honda whatever. It may be the thing that will help you out of a hole... water pump or whatever. Because I have used too much capacitor (space was not at a premium) the darn thing starts at about half a rope pull. It is way better than the original... you just have to look at the rope, and it starts almost.
The coil primary hooks onto to where it is marked (pins 46 and 47 note polarity), the coils secondary is earthed (usually body of coil). The coil input (primary)goes to the input pads (pins 49 and 50)...... and the HV secondary out goes to the sparkplug....simple stuff indeed.
In my case, as I have saved the vineyard.... you can guess what I'll be doing when they ripen..... picking, processing.... and drinking last years vintage as we bottle it.....
Hic... Hic
.....................oztules