running pathfinders without battery

[firekdp]

A zener is a diode that has been designed to breakdown at a certain voltage, ie it will block all current flow until it reaches a predetermined voltage. The Lucas 49345 diode has a breakdown voltage of about 13.5v, if the voltage rises above this then the diode breaks down and conducts current to earth producing heat (a heatsink was needed to disipate the heat and stop it damaging the diode). The higher the voltage the more current it will conduct and because of this the voltage across it will never be more than 13.5v and as all loads are in parallel with it the voltage across them never will either. When the voltage falls below 13.5v the diode will revert back again and block all current.The Lucas diode had a rating of 120W. The vespa regulator will work in a similar fashion but for AC.

[ArmandTanzarian]

Now its been a while (25 years) since I did basic electronics at college but a 120W stator should do what it says on the tin and be able to provide 120W of power under normal operation. Since power = Volts x Amps, 120 Watts at 12V = 10 Amps. A lot, but not a massive amount. Since most regualtors clip the voltage to around 13.5V that's only 8.8Amps

A regulator, in its most basic form simply keeps the voltage below 13V or so and I can't see how it can affet the overall power output. My best guess is that BGM stators are not actually putting out 120W at normal revs.

It could be "specmanship" in that the BGM stators are capable of producing 120W before they overload and catch fire but you'd need to be spinning the flywheel at 20,000 rpm to generate that much electricity.

Of course, I could be talking b0llocks, it has been 25 years and I wasn't very good at the subject anyway!

[Bufficus]

ok matey..........not quite sure if you agree with me or not..........but get the general idea.................i think...............
i may be asking a lot here from you mate............but ,i think this would be really helpfull to fellow scooterists.........if you could help.............
if for eg........someone had a gp.......and wanted to convert to a 120w bgm stator........what would you recomend/advise as per wiring spec...etc...........?
could you poss supply a wiring diagram ...........incorporating your advised mods /battery etc................?
thanks in advance FireDKp

Any help?



I only want to run one spot so I assume I can do away with the relay?

[firekdp]

Bufficus that is the simplest way of doing it but as the B+ output is only half wave the battery would take twice as long to charge compared to a full DC system. Sean if I get the chance I'll draw a diagram later on.

[soulsurfer]

This is what I have and think I'll be using but I wonder if it would power the lights if I wire the system directly to DC without using a battery or will a battery still be required?

[firekdp]

For a DC conversion the stator needs a small mod. The earth connection on the lighting coils needs to be broken and a new wire added. The podtronics could be swapped for a cheap rectifier from Maplins (about £3) but then a zener diode would need to be fitted (plug into junction box) to regulate the voltage.

[soulsurfer]

Spot on, I have the Podtronics waiting and have had the LI switch converted and fitted for a while now, the only thing I don't have are relays for each light Why are these needed and what and where can I get them? Thanks

[firekdp]

The relays are to save having to upgrade the wiring on the switch and to give the switch contacts a longer life. On the modified switch shown all power to the switch goes in on the black, trying to put too much current through it could cause a volt drop, lessening the voltage at the lamps.

[sean brady scooters]

thanks Firekdp,for taking the time and trouble.....for that......
i,m sure it will be very usefull to many people.......................

[Monty]

I know this has been done to death now and a battery is probably the easiest route, but it will charge slower than it is used with 2 spots.
If you connect the spots direct to the BGM without a regulator and the lights are on you should be OK till you turn the lights off. Thats when the regulator cuts in and its down to how much it can dump.
I have looked at the Podtronics one and not happy about modding the stator end to be 2 wire, and I dont have a battery at the mo.

Been looking at this Yamaha one

http://cgi.ebay.co.uk/YAMAHA-YZ426F-RM2 ... 240%3A1318

should cope with 150W
If the BGM will not put out 120W they should not be able to claim this.