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+--- Thread: Electrickery (/showthread.php?tid=8611)
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Electrickery - Hugh Barnes - 21-05-2023
Never my strong suit...
The Chummy seems to have started draining its battery. At first I thought it was a shagged battery after the Dynamator overcharged it (when previously fitted to the Cabriolet). A replacement was sought, but that also drains. This morning, some elimination tests showed up an 8amp discharge on the 'ignition' side of things (ie, only when the wire to the switch panel was affixed. I then found this...
When I contrived to set the cut out to its 'open' state, the discharge disappeared. Is this the correct set up, with a small spring keeping the cut out 'arm' with the points open until current causes them to shut? It looks as if it is, given what appear to be mounting points, but I would like to be certain...
Hugh
RE: Electrickery - David Stepney - 21-05-2023
Yes, there should be a light spring to keep the cutout points open. When the cutout coils are energised, the magnetic force overcomes the spring and the point close. As the dynamo ceases to charge, current starts to run from the battery back to the dynamo, which reverses the field of the current coil (the winding with the thick wire), which opposes the field in the voltage wire (the coil with the thin wire). The spring now is sufficiently strong to pull the points apart.
The spring only needs to be light. The stronger the spring, the more voltage is required to close the points.
Hope this explanation helps
RE: Electrickery - Hugh Barnes - 21-05-2023
Thank you David, perfect thanks, just as I expected. I've been hunting suitable springs this morning, but no luck yet...
RE: Electrickery - David Stepney - 21-05-2023
Hugh, I would be inclined to stretch the existing spring and reform the broken end to form a loop. Reattach it and that should restore normal service least until a more permanent spring is found.
RE: Electrickery - Hugh Barnes - 21-05-2023
I may, David, but I do wonder whether the existing spring may actually be a replacement, made from a cut down longer spring (and has broken at the point where it was bent to form a loop). The tension in the remaining portion is greater than I would have imagined. I'm on the track of some springs now that should hopefully get me out of trouble....
Going back to my new battery, I have had it on charge for the last 24 hours, having used it just briefly when I tried to start the car and noticed the fault. It still won't go above 6.28 amps and I think is sub-standard. It may well get returned as faulty tomorrow...
:o(
RE: Electrickery - Tiger - 21-05-2023
6.28 A sounds about correct .
RE: Electrickery - Hugh Barnes - 21-05-2023
I would have expected more in the region of 6.6/6.7?
RE: Electrickery - andrew34ruby - 21-05-2023
(21-05-2023, 05:35 PM)Hugh Barnes Wrote: I may, David, but I do wonder whether the existing spring may actually be a replacement, made from a cut down longer spring (and has broken at the point where it was bent to form a loop). The tension in the remaining portion is greater than I would have imagined. I'm on the track of some springs now that should hopefully get me out of trouble....
Going back to my new battery, I have had it on charge for the last 24 hours, having used it just briefly when I tried to start the car and noticed the fault. It still won't go above 6.28 amps and I think is sub-standard. It may well get returned as faulty tomorrow...
:o(
6.28 amps? Do you mean amps?
RE: Electrickery - Steve Jones - 21-05-2023
I suspect your point that your spring is a replacement might be correct. This is what mine looks like and I've a spare cut out with a similar spring.
Steve
RE: Electrickery - Hugh Barnes - 21-05-2023
Yes, volts, not amps..
Thanks Steve, that shows it perfectly. If possible could you give men an idea of the tension of the spring. The vaguest terms, of course, but I'm assuming there wont be a huge amount of tension in it?
HUgh
Edit: A fellow forumist has kindly popped some springs in the post but notes that none of them match the one shown in Steve's photo. A long-shot, I know, but if anyone has such a spring, perhaps on an otherwise knackered cut out, I would gladly take it off their hands with suitable recompense...
Further Edit: This morning, after another overnight period on charge, the battery shows 6.39 volts and the battery charger still suggests it is not fully charged... ?