BobZilla's Custom Build

[Gary Hammond]

Hi Bob,

Boy you guys are a tough crowd!

Nobody cared about the cap dumper video, nobody cares about a new build.

I guess I farted huh?

Sometimes I get so wrapped up in my own experiments that I fail to comment on what others are doing.

I did enjoy the video on your cap dump modification results. It looks to be working very well!

I do find it curious, however, that you are using 24 volts on the primary to charge only 12 volts on the output side. I understand that the machine likes to run on the higher voltage, but why not charge the two garden batteries in series instead of in parallel?

The new designs you posted also look good.
Regards

[BobZilla]

Bob,

plastic please, aluminum can get eddy currents in it, if the aluminum is not spinning it will affect your build. let mew know about the coils, if you have a design I can print it for you, and can make the bobbins any size you want.

Tom C

Thanks for the advice Tom. I am really on the fence about the material, it did cross my mind that the aluminum would cause problems. The other big machine I build is starting to show slight warpage on the frame now which is why I thought I should use tougher material. That thing has the weight of 8 coils on it plus the circuits and flywheel. It still runs good at this point but the warp concerns me. I may have to make it back into a 4 coiler to reduce the weight.

I designed some simple coil holders which I was thinking about aluminum as the material because the plastic cannot be used unless I make it really thick, that is according to the software I use.

The intent with this machine is very far from the normal mono pole. I am trying to make a transistor less model that will use clap contacts for switching mounted on the wheel. That is what the cut-outs on the frame are for, too mount the clapper. If it does not work out I can always go traditional with it. I understand that true contact switching is MUCH better than transistors because of the little bit of capacitance held in the p junction, it makes for a fluffy off rather than immediate. If anyone has ever played with just shorting a coil on a battery you may know what I mean about that.

I do find it curious, however, that you are using 24 volts on the primary to charge only 12 volts on the output side. I understand that the machine likes to run on the higher voltage, but why not charge the two garden batteries in series instead of in parallel?

Hi Gary,
Always good to hear from you. Funny you ask because I did try that later on and blew some fets. Those caps are 50v so to get to a double voltage for the dump I was practically at full on the cap which I think unleashed a huge current, more than the fets could handle. Some of them locked the D&S closed so I lost switching.

When not using a dumper I often do 24 on both ends though.

[BobZilla]

Another set of plans. I think this might be what I go with.

The frame is about 1ft tall, 2 inch coils, 5 inch rotor.

[BobZilla]

Greetings,
So I have not played with this machine is awhile because the smaller one in my last post was built and has it's own thread in the other section.

I have put this one (8 coiler) back on my bench so that I can work on the smaller one awhile. I had forgotten how much fun this one is ;-)

This chart and the video is showing a spin up with a cap dumper attached. The charge battery was already finished so this is only bringing it back up to peak. The cap dump is set to half a second loop with 66kuf. This is not a full run, it's just a look at how the machine settles in on a charge.




Video:
https://onedrive.live.com/redir?resi...nt=video%2cmp4