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Re: disappointing DC conversion...
Posted: Mon Dec 21, 2009 7:47 pm
by cezeta
firekdp wrote:cezeta wrote:its worth checking this out as i was under the impression that a generator is rated at its potential wattage rather than what is being generated all of the time. ie if no load is present then it is not putting any load on the engine but as soon as an electrical load is applied then the engine is put under load to provide the power.......something to do with apposing magnetic fields from the coils which only exist with a load present v the magnets on the flywheel......
ooh...distant memory, i could be wrong.
you can sometime hear this in your car when you flick the lights on or air con for that matter as the same applies. a mate of mine is trying the same thing, he is not a forum user so if he goes for the taffy kit i will report back. worth keeping on the back burner incase you are not happy with the outcome of what you are doing
An alternator has an armature fed with current via slip rings to produce the magnetic field. The regulator on this system is a transistor which switches the current to the armature on and off. If the voltage rises above above 14v the the transistor will switch off the armature current and the field will collapse and so will the voltage. So the alternator will only produce power when needed.
Because a stator has permanent magnets the power will always be produced and the only way to keep the voltage stable is to dump the power not being used. So excess wattage must be used by the regulator and is why the reg has a wattage rating (the amount it can dump)
thanks for the explanation, we always end up with the naff end of the stick
fortunatly i dont have a need for the extra wattage but if you are going to have those lamps bolted on then its worth getting them to work. i ve been caught in the swiss alps in the rain in the dark and would have loved a set of those lamps. there is led technology bulbs on the way so matbe these will help too.
Re: disappointing DC conversion...
Posted: Mon Dec 21, 2009 10:18 pm
by martinr
been reading this posting with interest the gp project im doing at the moment is having a 12vdc digital speedo/fuel gauge plus digital rev counter/temp gauge and four led indicators/led rear light. im going to use a varitronic ignition and have a battery. ive got another scoot with a varitronic on it i tested the voltage coming out of the regulator today that keeps the battery charged it was reading 5 vdc at low revs and 7 vdc at higher revs. now heres the question can i run all that direct from the battery and let the stator recharge it. while running headlight/horn on AC or should i go full DC. has anybody got a list of parts i need and complete wireing diagram to go full DC
Re: disappointing DC conversion...
Posted: Tue Dec 22, 2009 2:15 am
by byron
the electrex unit didn't perform too well, but it's possibly not designed to do what we are trying to achieve...
big thanks to firekdp for steering me along with some more tests.
interestingly my readings on the rectifier output of only 3v DC without the battery had been with the lights off, when i turned the [standard] lights on, the reading went up to around 9v DC, enough to run the lights and probably as much as a usual electronic ignition system puts out [in AC]...
so I've made up some leads and a chart and have now got about ten other units of various types to try out, including two other new Wassell rectifiers.
I will post results, hopefully later in the week, although some christmas stuff to do sometime...
as a sidenote, when I googled "wassel" [missing the last L] earlier, according to the urban dictionary
to wassel is to "
To dress up like a scientist just so one can masturbate while wearing a lab coat and safety goggles
Re: disappointing DC conversion...
Posted: Tue Dec 22, 2009 10:02 am
by Angry Bloke
byron wrote:
as a sidenote, when I googled "wassel" [missing the last L] earlier, according to the urban dictionary
to wassel is to "
To dress up like a scientist just so one can masturbate while wearing a lab coat and safety goggles
I don't know, whatever next -you've been happily doing something in the privacy of your own shed for years then someone just has to pigeon hole you
Good work mate keep experimenting -a eureka moment is imminent
Re: disappointing DC conversion...
Posted: Tue Dec 22, 2009 12:10 pm
by T5-190
Great post guys, a real insight. I was always going to have this problem with the KX project, it only has a very small flywheel and stator. There are no lighting coils on it at all. One coil can be fitted but it only outputs enough for a brake light bulb. So I did some digging and have found the worlds smallest alternator. It is from a small digger, Bobcat etc. This thing is only about 100mm long, and gives out upto an amazing 40 amps at 13 volts. This will be mounted on a small bracket and driven by a small V pully from the flywheel.
Re: disappointing DC conversion...
Posted: Tue Dec 22, 2009 2:27 pm
by soulsurfer
firekdp wrote: The cap on monty's system is masking a problem on his set-up in the same way that the battery is on yours.
I've fitted two of these without any issues at all, as have many others, but this is the second one I've heard of with this problem. Kev, assuming the POD is okay, what sort of problem would/could the capacitor be masking?
Monty, how is yours going, with or without cap?
Martin, I'm not sure whether you're looking to run a standard(ish) type DC system or adapt your Varitronic
Re: disappointing DC conversion...
Posted: Tue Dec 22, 2009 2:44 pm
by firekdp
soulsurfer wrote:I've fitted two of these without any issues at all, as have many others, but this is the second one I've heard of with this problem. Kev, assuming the POD is okay, what sort of problem would/could the capacitor be masking?
On Monty's, if I remember correctly without the cap his lights were dim as the voltage was only about 7v. Only when the cap was added did the volts rise to 12-13v. I presume that his system was only supplying half wave, because the ave voltage of an on/off 13v peak would be half of that. A cap that charges on the available peak and discharges on the missing one would fill in for it and bring the average volts back up. The only problem is that the system would be delivering less power so will probably suffer at higher current demands.
Re: disappointing DC conversion...
Posted: Tue Dec 22, 2009 4:18 pm
by soulsurfer
So you would assume a duff reg/rec?
Re: disappointing DC conversion...
Posted: Tue Dec 22, 2009 4:37 pm
by firekdp
If it is a half wave output, it could only be caused by a fault on the stator and/or its wiring or a dodgy reg/rec.
Re: disappointing DC conversion...
Posted: Tue Dec 22, 2009 7:32 pm
by CANbus
martinr wrote:been reading this posting with interest the gp project im doing at the moment is having a 12vdc digital speedo/fuel gauge plus digital rev counter/temp gauge and four led indicators/led rear light. im going to use a varitronic ignition and have a battery. ive got another scoot with a varitronic on it i tested the voltage coming out of the regulator today that keeps the battery charged it was reading 5 vdc at low revs and 7 vdc at higher revs. now heres the question can i run all that direct from the battery and let the stator recharge it. while running headlight/horn on AC or should i go full DC. has anybody got a list of parts i need and complete wireing diagram to go full DC
martinr, you may find this link of some help ---->
http://scooterotica.org/forum/viewtopic.php?f=7&t=3599
by carring out this conversion I'm running a TI DSP no problem, and plan to use a digital speedo shortly.