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Post by Deleted on Nov 5, 2022 19:19:12 GMT
telemachusIf I connected electronic items to the 12v battery (which is charged via the generator through a regulator / rectifier unit) would this result in a 'spikey' signal which would ruin said electronics and if so is there any device that could be placed in-line to prevent undesirable surges, or is this what the reg-rec unit is already doing?
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Post by twerpv3 on Nov 5, 2022 19:48:52 GMT
It might, but then it might not.
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Post by telemachus on Nov 5, 2022 22:16:30 GMT
telemachus If I connected electronic items to the 12v battery (which is charged via the generator through a regulator / rectifier unit) would this result in a 'spikey' signal which would ruin said electronics and if so is there any device that could be placed in-line to prevent undesirable surges, or is this what the reg-rec unit is already doing? Just depends on how sensitive the “electronic items” are. In general the motorbike electrical system is held at 12v or whatever by the regulator/rectifier. However high speed voltage transients can still be present eg when releasing the starter button. These sort of transients only last microseconds but are very pervasive. So an “electronic item” might have some protection against that sort of thing, or might not. If in doubt you could always add a tranzorb in parallel, to “soak away” any high speed transients. A tranzorb is a bit like a zener diode, only much faster. |
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Post by Deleted on Nov 5, 2022 22:40:00 GMT
telemachus If I connected electronic items to the 12v battery (which is charged via the generator through a regulator / rectifier unit) would this result in a 'spikey' signal which would ruin said electronics and if so is there any device that could be placed in-line to prevent undesirable surges, or is this what the reg-rec unit is already doing? Just depends on how sensitive the “electronic items” are. In general the motorbike electrical system is held at 12v or whatever by the regulator/rectifier. However high speed voltage transients can still be present eg when releasing the starter button. These sort of transients only last microseconds but are very pervasive. So an “electronic item” might have some protection against that sort of thing, or might not. If in doubt you could always add a tranzorb in parallel, to “soak away” any high speed transients. A tranzorb is a bit like a zener diode, only much faster. The start system is kick only. And the engine would start even if the battery is completely dead, although I think it is still needed in order that the generator has somewhere to discharge to (ETA thinking about it really hard it's likely more accurate to say that a battery, dead or alive, is needed to complete the ignition circuit). If the generator output is measured at the batt terminals, it shows the voltage varies with engine speed - as little as 11.8v to 14.2v (ish). So what I'm thinking about is a device that could accept that variance but output a steady 12v. Perhaps it would help to know the system is split-phase, and I am only vaguely aware what that means, but since the 'park' light, indicators and horn work without the engine running they must take power directly from the battery whereas the main and rear lights are powered solely by generator output. The system produces a paltry 45W which is just barely adequate to power the standard equipment, and so if I were to introduce more demand then more power is needed; there is a 100W aftermarket generator which I understand is single-phase. Right now I don't pretend to understand how that makes for a direct swap but it apparently does. Things I might want to attach to the bike is principally a mobile phone / tablet. I originally imagined simply cutting the plug from a standard in-car charger and wiring it to the batt with an in-line fuse would be sufficient, but I suspect the phone wouldn't tolerate the variable current particularly well. Any further thoughts and comments appreciated. |
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Post by JohnV on Nov 6, 2022 6:47:55 GMT
if you are using a car type GPS they don't actually use 12V as such but convert it with an internal PSU to it's own requirements
this plus the fact they are designed for use in vehicles where transients and a voltage that varies between 11V and 14.7V is the norm
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Post by Deleted on Nov 6, 2022 7:03:46 GMT
It would much more likely be a phone or tablet. If it were your actual sat-nav I'd want a waterproof item and the prices for such a thing are daft.
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Post by telemachus on Nov 6, 2022 10:13:37 GMT
If you want to charge a phone etc, that is 5v. So a 12v to 5v USB adaptor should be OK. You can get ones designed for motorbikes - ie weatherproof. www.ebay.co.uk/itm/304570663722Old fashioned small jap motorbikes tended to use an unregulated permanent magnet alternator. The headlight switch selects extra stator windings to boost the output to run the headlight. Some don’t bother to rectify the headlight power - just sends ac at around 12v direct to the headlight. Some add the power to the rectifier/battery circuit and the headlight is dc. Problem with that is that if the headlight bulb blows, you get the extra power without the load to disperse it. Ie the battery voltage rises to be very high. |
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Post by jim on Nov 6, 2022 12:13:29 GMT
I mounted a variable voltage input usb socket on my ebike, for phone, charging the led lights etc.
There are a few variations on Amazon, from a circuit board buck converter to fancy encapsulated handlebar mount ones. Cheap enough to experiment with.
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Post by Deleted on Nov 6, 2022 15:47:57 GMT
If you want to charge a phone etc, that is 5v. So a 12v to 5v USB adaptor should be OK. You can get ones designed for motorbikes - ie weatherproof. www.ebay.co.uk/itm/304570663722Old fashioned small jap motorbikes tended to use an unregulated permanent magnet alternator. The headlight switch selects extra stator windings to boost the output to run the headlight. Some don’t bother to rectify the headlight power - just sends ac at around 12v direct to the headlight. Some add the power to the rectifier/battery circuit and the headlight is dc. Problem with that is that if the headlight bulb blows, you get the extra power without the load to disperse it. Ie the battery voltage rises to be very high. Crikey they'll invent a flying machine next. Yep, that would sort the phone issue nicely. Thanks. Also the aftermarket 100W generator seems to fit that description [Some add the power to the rectifier/battery circuit and the headlight is dc], I shall investigate. Still wondering about a unit that is designed to be fed by an independent batt at 12v which wouldn't be satisfied by 5v. But maybe its a bridge too far. Thing is the gadge seems to be designed for a surge at engine start which then settles; the Cub voltage varies continuously. |
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Post by Deleted on Nov 6, 2022 17:43:39 GMT
if the headlight bulb blows, you get the extra power without the load to disperse it. Ie the battery voltage rises to be very high. I wonder if a capacitor would compensate for this. |
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Post by telemachus on Nov 6, 2022 18:20:17 GMT
if the headlight bulb blows, you get the extra power without the load to disperse it. Ie the battery voltage rises to be very high. I wonder if a capacitor would compensate for this. No, a capacitor would only momentarily absorb a surge. Some bikes with fixed output permanent magnet alternators used a zener diode on a big heat sink to absorb the unwanted extra power. I am thinking of my 1970s triumph trident. |
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Deleted
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Post by Deleted on Nov 6, 2022 18:24:39 GMT
I wonder if a capacitor would compensate for this. No, a capacitor would only momentarily absorb a surge. Some bikes with fixed output permanent magnet alternators used a zener diode on a big heat sink to absorb the unwanted extra power. I am thinking of my 1970s triumph trident. As do many 😊😍 |
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Post by Deleted on Nov 6, 2022 18:32:50 GMT
I wonder if a capacitor would compensate for this. No, a capacitor would only momentarily absorb a surge. Some bikes with fixed output permanent magnet alternators used a zener diode on a big heat sink to absorb the unwanted extra power. I am thinking of my 1970s triumph trident. Bur perhaps this is the regulator function of the reg/rec unit? |
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Post by JohnV on Nov 6, 2022 20:40:02 GMT
probably something on the line of Jims idea might be ok. A regulated powersupply fed from the battery,
If the supply was lower than the regulating voltage then the output would be as well but it would prevent any overvoltage.
You really need to make up your mind on exactly what you want to use and what the supply requirements are for those particular items
before that is decided, a lot of this is whistling in the dark
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Post by Deleted on Nov 6, 2022 21:28:08 GMT
You really need to make up your mind on exactly what you want to use and what the supply requirements are for those particular items This is true. The first most important thing would be to up the wattage of the headlamp bulb (at present 45W) which I hope would leave something spare. I have a notion of going further on a scooter than is normally done hence the desire for a phone charge capability, and that would need 5W or so. But scooting about has revisited the reality that you just don't get as much respect from other road users in the same way that a more aggressive-looking machine does, which led to myself considering a dash-cam type situation. Maybe just do what the bicyclists do. Several years ago, while out driving through some back streets, I happened on a chap lying in the road with his scooter (co-incidentally also a 90) fairly well smashed up. He had a broken ankle. Whomever had hit him didn't stick around. Despite his injuries, the middle-eastern looking chap refused an ambulance; in fact he begged me not to call. Can't think why. He had already called a friend though, who, when he arrived, assumed I was the party at fault...nice. |
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