Rotax voltage regulator query

[psg]

Hi everyone

I have a Flash 2 Alpha with a 462. I have wanted to put on a battery to power a radio and gps.I currently only have a water temp gauge working off the regulator. I measured the voltage from the regulator going to the gauge and I get 5 volts. This is working the temp gauge ok but obviously wont charge a battery. So I checked the voltage comming out the coils and I get about 25v ac on both the outputs. When I connect the regulator with the motor running I get sparks comming from the wires indicating a short in the regulator unit. So I buy a new one. The new one has the same problem. It just basically shorts out the coil and puts about 5v out. I cant see the new one to be faulty really but hey who knows. Does anyone have any ideas what it could be?

Reagrds
Sacha

[Wargames]

So I checked the voltage comming out the coils and I get about 25v ac on both the outputs.

At what RPM is that. Should be around 45V ac at 5500 - 6000 rpm.

[psg]

Hi

It does go to about 35v on a higher RPM. I was not really concerned as I changed the coils as well but still had the same problem.

Regards
Sacha

[Morph]

PSG,

I have no knowledge of the 462 engine but for the other 2 stroke Rotax motors this is the case

The motor puts out 170Watts of power at 6000rpm. This can give voltages as high at 35V and a minimum of 17 at idle

The voltage regulator is supposed to reduce this voltage to +/- 13.5Volts. This means you can put a 12V Battery across the output and the voltage will be able to charge the battery. The battery should be 9 to 16 Amp/Hour

I have attached a wiring diagram and the recommended regulator

[psg]

Hi Morph

Thanks for the info. I somehow suspect the coil now. Il going to get a new one when I get a chance and Ill let you know what I find.

[psg]

Hi all

Well now im confused.I replaced the coil and still no power from the black wire to charge the battery. So I went to P&M and explained the problem. They were also not shure what to say but gave me 3 regulators they had in stock to test ( they were nit shure if they worked or not). Well none worked. So someone suggested I put a car light globe across the coil to see if it was producing power.It lit brightly at 2000rpm and then blew at about 4000rpm. So I can only guess its all 4 regulators??? Im pretty ok with electronics so would like to build my own but to get it approved will be a nightmare. PLEASE Its a simple circuit and its really getting to me now. Help please someone before I go mad.

[Duck Rogers]

.......Im pretty ok with electronics so would like to build my own but to get it approved will be a nightmare.

You need approval for that in the UK?

[Morph]

So someone suggested I put a car light globe across the coil to see if it was producing power.It lit brightly at 2000rpm and then blew at about 4000rpm.

Not surprising, a 12V globe will blow at 25Volts. This test is supposed to be on the other side of the regulator. Use a voltmeter set to AC, across the coils and tell us what the Max voltage is. I would start with a setting of 200V or more on the meter, just in case you blow your voltmeter as well

[psg]

Hi Morph

Yes you are correct I just was testing weather the coil puts out enough current as well as voltage as I measured the voltage and get about 30vac from memory. So there is power comming out the coils so it has to be the regulator however the new one is only putting out a few volts.

[Wargames]

Real stupid question: Are you wiring it correctly? Any leaks/shorts maybe??

I had a leak somewhere, and mine only kicked out 7V. My advice, check all wires, and I mean all.

[psg]

HI Wargames

What I have done is remove all the wiring going to instruments ect.I then only have two yellow wires connected to the coil and the casing of the regulator earthed.The black wire should put out 12v but it doesnt. I got the paperwork from the BMAA today to apply to do the mod for my own regulator. Im looking at doing a duel one so one regulator circuit per coil. Ill use the low current one for instruments and and the larger one for charging the battery and strobes ect.Thus having two independant 12v supplies. Has anybody got and ideas to add as I think it could be handy for others to have something like this? (I still want to get to the bottom of this problem just out of interest and pride I guess)

Cheers
Sacha

[psg]

Hi All

Problem solved. I put in a battery and it works fine now charging at 13.8v. So simple when you know how.


Cheers
Sacha