mini-Tesla

[hartiberlin]

Yes, EM, Witricity looks exactly like 2 Tesla coils in resonance,the second backwards, receiving the energy.
BTW, what power rating did your Flourorescent bulb have ? 11 Watts and how bright was it really ? Modern CMos Digital cameras are mostly more sensitive than the human eye to this light, so they expose the picture more bightly.
Did you have less than 500 milliAmps of input current from your battery pack ? Was it around 9 to 12 Volts supply voltage ?
Many thanks.

[Carl.]

thanks for the links, slapper

I now understand what they're doing a bit more.  Did you guys see their diagram in the pdf file?   The transmitter is just one loop of wire like they say in the article.  What's interesting here is that the coils are not connected to anything, they're just resonators at a certain operating frequency and bridge the gap with resonant energy.   You then just bring in your transmiter and receiver loops close to the resonators, and they behave as if they're very close together and coupled.   I like the theory they present.  This is close to Tesla coils.  The one turn loops are like the primary (or pancake) coils driving the tesla secondary coil, and the resonator multi turn coils play the part of the secondary in the tesla coil.

EM

EM, looks kinda like a TPU doesn't it???

control coils are resonator coils, collectors are theose single loops, the transmitter could be the small torrid??? Might be a reach....


sorry about the off topic post but I couldn't help it. Please post the component values for the mini tesla coil, I would like to build a small toy as well, if nothing than to get a bit of use out of those old florescent tubes. 

BTW, what did you use for the form for the upright coil? looks like a small btit of PVC.

[EMdevices]

The compact florescent bulb I was using was rated at 15 watts.Ã, Ã,  It was just as bright as when operated from the grid electricity.Ã, Ã,  Like I was mentioning, I didn't get enough time to measure any input power before the glass broke. I haven't cut up another one yet but I will soon.Ã, Ã,  Last night I tried to measure the amps from the battery and my digital meter was flaking out, it's all the RF that screwes it up.Ã,  I'm working on setting up for some decent measurements once I transfer everything to a PCB, and I'll put in lots of RF chocks and capacitors to get good readings.Ã,  The voltage was about 10 volts (8 AAA each of about 1.27 Volts or so)

EM

P.S.Ã,  Carl, the bias resistors need to fit your particular transistor,Ã,  I'm not sure what mine is, I just have a box full of transistors, it's an NPN that much I know, and you tweek the resitor values to set the correct voltage.Ã,  On the Collpits I'm using 10 K resistors, on the MOSFETÃ,  10K upper and 1.5K bottom, seems to work ok, but I'll be impelementing the circuit with a variable potentiomenter for more control.Ã, Ã,  The form is a small plastic tube container with a lid, that was used for some drinks (Fizz pop, I believe), but you can use other plastic or glass type of materials.Ã,  I put a hole in the lid and put a screw from the inside and attached the bottom wire to it, then I just snapped the tube into the lid, or cap.

[hartiberlin]

Hi EM, you only can use shielded analog meters for these measurements, and yes be sure to use lots of chokes and caps as low pass filters before them and put them at least 3 Meters away from the Tesla coil, otherwise it will jamm the meters...
Good luck.

[Carl.]

P.S.  Carl, the bias resistors need to fit your particular transistor,  I'm not sure what mine is, I just have a box full of transistors, it's an NPN that much I know, and you tweek the resitor values to set the correct voltage.  On the Collpits I'm using 10 K resistors, on the MOSFET  10K upper and 1.5K bottom, seems to work ok, but I'll be impelementing the circuit with a variable potentiomenter for more control.   The form is a small plastic tube container with a lid, that was used for some drinks (Fizz pop, I believe), but you can use other plastic or glass type of materials.  I put a hole in the lid and put a screw from the inside and attached the bottom wire to it, then I just snapped the tube into the lid, or cap.

@EM,

cool, I have quite a few transistors and various resistors and caps (from my TV shop days), I will just throw one together this weekend. I don't know if I have any Mosfets left??? gotta look.

I think I might use a plastic cigar tube for the former. I still have plenty of magnet wire left from my TPU supplies.

Time to blow some Sh*t up!!! lol