Lighting coil resistance

[Knowledge]

Hi,

I'm building a DC system using a Wassell regulator/rectifier, so I have wired the four lighting coils together and run a yellow wire from each end of the series. When I run the scooter, I get a rather poor 4.5v AC out of the two yellows and no increase in output with a rise in revs.

Now what I have done is not so different to most AC systems, it is just that output on AC systems is measured between the one yellow and earth. However, output on such a system usually rises to 16-18v without many revs.

I have checked the resistance on three stators (a Vespa stator, an Indian stator and my new stator) and the readings are not consistent.

What should the resistance of the 4 lighting coils be? Can someone take 5 minutes to measure between their yellow wire from the stator, and earth? You don't even need to start the engine. The more replies I get, the better.

Thanks in advance

[Knowledge]

I have got it sussed.

I was reading the AC voltage output from the two yellows while they were connected to the Wassell regulator/rectifier, and got 4.5v. When I disconnected them from the Wassell, I got a healthy 18-19volts output from the stator. Odd.

I have now checked the system on the rectified side of the Wassell (which perhaps I should have done before I posted) and I can see the DC circuit is provided with a healthy 14.7volts at tickver; enough to keep the battery charged. When I kill the ignition, this drops to 13.4volts, which is correct for a battery "at rest".

It all looks promising. You can see why people rave about this conversion. OK, you add a battery to the circuit, but all the other advantages seem positive (pun intended).

PS. The resistance on 3 different stators was between 0.7 and 0.9, and I have now decided that one of the Vespa stators is faulty, hence mad readings. The main thing is that the output is good.

[firekdp]

Hi,

I'm building a DC system using a Wassell regulator/rectifier, so I have wired the four lighting coils together and run a yellow wire from each end of the series. When I run the scooter, I get a rather poor 4.5v AC out of the two yellows and no increase in output with a rise in revs.

I take it that the 4.5v reading was taken without any load on the stator? This shows why this system ideally needs a battery or capacitor to load the system to relieve pressure on the reg and the stator itself.

[Knowledge]

Curiously, it was the other way around. When the stator was connected to the rest of the loom, I was able to read only 4.5v across the two output yellows from the stator. When I disconnected it, I measured 18v across them.

I reconnected and measured the output from the regulator, and got good DC power. It still reads 4.5v on the input side but I never claimed to understand the world of electrickery.

However, I have checked my ohmeter, and it isn't reading correctly, so please ignore the resistance figures I quoted earlier in this thread.