New Bike Wheel with 9 filar 18awg coil!

[Woody]

Howdy to everyone,

I just wanted to post some pictures of my newest build. I took out the old r-charge #23awg and #26awg bifilar coil and wound a new 130' 9 filar #18awg and #20awg coil. I heard some weather was coming in so I litzed the wire in the driveway and the next day we sure enough got hammered by snow for the next few days. I now had a bunch of litzed wire and all the components I needed to upgrade my old bike wheel. Made for a great winter storm indoor project! I could not get all that wire on a standard Pittsfield spool so I took two of them and cut about 1/2 inch off one end and super glued the two longer pieces together for a 5" long spool. The wire just fit on that spool. Here are some pics:

In this first one, you can see the old coil in the foreground. Quite a difference!









Just beginning the first runs. Looks good so far. I'm starting with 220 ohm resistors on the bases. So far my draw on primary is 440ma with about 200 RPM and 178 ohms on the trigger pot.

-Woody

[Gary Hammond]

Hi Woody,
Are you running it in attraction mode or repulsion mode?

[Woody]

Hi Woody,
Are you running it in attraction mode or repulsion mode?

Howdy Gary,

I built this one to run in attraction mode. Still tuning it. I'm getting better results with a lower trigger resistance. I just did a run with a couple of 5ah flabs. 1 hour and 20 minutes took the secondary from 12.36v up to 15.42v. The primary draw was 760ma (I know a little high for a battery this size) and trigger resistance was at 103 ohms. RPM about 173.

-Woody

[Aaron Murakami]

Howdy Gary,

I built this one to run in attraction mode. Still tuning it. I'm getting better results with a lower trigger resistance. I just did a run with a couple of 5ah flabs. 1 hour and 20 minutes took the secondary from 12.36v up to 15.42v. The primary draw was 760ma (I know a little high for a battery this size) and trigger resistance was at 103 ohms. RPM about 173.

-Woody

Looks great Woody!

With it tuned and running a while, what is the temperature of your transistors since you're running in attraction mode? You can probably tell you don't even need heat sinks.

[Woody]

Looks great Woody!

With it tuned and running a while, what is the temperature of your transistors since you're running in attraction mode? You can probably tell you don't even need heat sinks.

Aaron, yeah you noticed there are no heat sinks on those transistors! They are running COLD and so are the resistors, diodes, charging battery and coil. No heat anywhere. I have never had a problem with warm transistors on any of my builds, so I decided that the heat sinks were superfluous. Winding that coil was a PAIN!!! But it was worth it. It is the new star of my lab.

I noticed that there is a very obvious change in the sound of the coil when I change the resistance on the trigger pot. It is so pronounced that once you know what your listening for, you can adjust it just by the sound alone. The response is immediate and noticeable even with tiny adjustments. Very cool!

-Woody

[Aaron Murakami]

Woody,

If you hear sound, your resistance is probably too high - it is on the verge of going into self oscillation probably. If you scope it, you may see multiple events per cycle and you only want one event per cycle. Reduce resistance until there is one event per cycle.

In attraction mode, everything runs colder.

In repulsion mode, when the coil charges, it is bucking up against an opposing North magnetic field on the permanent magnet on the wheel so it has to work harder to charge that coil. That is where heat is produced and none of that you can get back.

In attraction mode, when the coil charges, it is pulling an opposite permanent magnetic field to it and the permanent magnet and coil are magnetically in alignment with each other so you have none of this loss, but you do get extra gain in both mechanical and electrical recovery. That is why in attraction mode, everything is so cold.

[Woody]

Woody,

If you hear sound, your resistance is probably too high - it is on the verge of going into self oscillation probably. If you scope it, you may see multiple events per cycle and you only want one event per cycle. Reduce resistance until there is one event per cycle.

In attraction mode, everything runs colder.

In repulsion mode, when the coil charges, it is bucking up against an opposing North magnetic field on the permanent magnet on the wheel so it has to work harder to charge that coil. That is where heat is produced and none of that you can get back.

In attraction mode, when the coil charges, it is pulling an opposite permanent magnetic field to it and the permanent magnet and coil are magnetically in alignment with each other so you have none of this loss, but you do get extra gain in both mechanical and electrical recovery. That is why in attraction mode, everything is so cold.

Thanks Aaron. I have not put the scope on it yet to check the pulses per magnet. I'll do that tonight. It was actually making these sounds at a much lower resistance than I was running it at before, so I don't think it was approaching self oscillation. It was actually quieter at the higher resistance. The scope will tell the tale tonight. I'll report back.

-Woody

[Woody]

Well, the scope revealed that I was indeed running at the higher resistance sweet spot with 2 pulses per magnet. You nailed it Aaron! I reduced the trigger pot to 87ohms to obtain one pulse per magnet, and the RPM increased to over 300. The draw on primary increased to 1.35a. The charging seems to be better too. I figure the system is probably best suited to batteries of around 30ah now, based on the amp draw where this system seems to be happy to operate. Thanks for the analysis Aaron!

-Woody

[Aaron Murakami]

Glad you found that was it! Looking forward to more reports.

[Faraday88]

Hi Woody,
Nice set-up and your lab too! how do you manage to keep it so neat and presentable..?
Best regards,
Faraday88.