[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [TCML] static gap singing coil hybrid.



If you need a beefy resistor... 

Try stacking squares of carbon and just tapping the ends in a vice. graphite might work as well 
You get a variable resistor where a fixed metal plate and a movable one serve as the terminals ; the resistance value is reduced by applying pressure to the movable plate. 

I have no idea what the effective resistance range that can be achieved would be, but I know that these guys can handle hundreds of amps no problem 
a lot lighter than a salt water resistor as well =) 


Thanks, 
John "Jay" Howson IV 


"Why thank you, I will be happy to take those electrons off you hands." 


----- Original Message ----- 
From: "Scott Bogard" <sdbogard@xxxxxxxxx> 
To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx> 
Sent: Wednesday, January 26, 2011 10:14:27 PM 
Subject: Re: [TCML] static gap singing coil hybrid. 

Oh yes, that makes sense... If I get impatient I'll probably just make 
a resistor out of a bucket of salt water and some metal plates, very 
inefficient and short lived but I imagine it will prevent inrush to the 
gap and still allow the tank cap to charge. It will be some time before 
I build a prototype as I have no idea how to interface with midi, though 
I suppose I could rig a 555 timer with about 4% duty cycle at 30Hz-5khz 
to trigger another driving a flyback at 100 kHz to be my trigger, that 
way I can get at least steady sound, pitch adjustable with a 
potentiometer as proof of concept, and not worry about midi until later. 

Scott Bogard. 

On 1/25/2011 9:33 PM, Phillip Slawinski wrote: 
> Scott, 
> 
> The MOTs will probably work. Also the charging inductor serves the purpose 
> of limiting the current from the filter capacitors when the spark gap is 
> triggered. Remove the inductor, and you end up dumping the the filter 
> capacitors across the spark gap when it's triggered. 
> 
> -Phillip 
> 
> On Tue, Jan 25, 2011 at 17:55, Scott Bogard<sdbogard@xxxxxxxxx> wrote: 
> 
>> Phillip, 
>> I was planning on eventually building a DC coil eventually anyway, 
>> and I have enough microwave oven capacitors and diodes that I could build a 
>> MOT based level shifter with all the current I can handle, not sure if that 
>> would cut it or if I would need a resonate charging inductor, which could be 
>> made with more MOTs in theory. Since it is triggered it shouldn't need an 
>> especially high voltage I suppose, so 4kV was where I was aiming. The 
>> biggest hurtle I see is cooling, having that arc that close to glass for 
>> prolonged periods will be tricky, but maybe if I run cold air or oil or even 
>> water through the tube, its life expectancy should be similar to glass jar 
>> capacitors I'd imagine, even if I only get 15 minutes out of it glass tubing 
>> is a lot cheaper than IGBT's, and is easy to replace... 
>> 
>> Scott. 
>> 
>> 
>> On 1/25/2011 1:13 PM, Phillip Slawinski wrote: 
>> 
>>> Scott, 
>>> 
>>> While this looks okay in theory, there would be some limitations. The 
>>> main 
>>> limitation would be that this could only work with a DC charging system. 
>>> This adds complexity to the project, because you must then locate large HV 
>>> filter caps, diodes, and a properly designed charging reactor. Aside from 
>>> those issues, I don't see any fundamental reasons why it can't be done. 
>>> If 
>>> you do this please share your results. 
>>> 
>>> -Phillip 
>>> 
>>> On Tue, Jan 25, 2011 at 11:44, Scott Bogard<sdbogard@xxxxxxxxx> wrote: 
>>> 
>>> Greetings all, 
>>>> So I was looking at this web page today at work for no particular 
>>>> reason... 
>>>> http://www.glacialwanderer.com/hobbyrobotics/ 
>>>> If I am understanding this correctly, he essentially built a spark gap 
>>>> triggered by the corona around the inner glass tube from his trigger 
>>>> coil. If that is correct would it be terribly easy (if extremely 
>>>> inefficient) to make a singing coil by constructing a similar spark 
>>>> gap (with better cooling for actual run times) and just trigger the 
>>>> inner coil with a midi signal. This way for those of us who don't 
>>>> want to tackle DRSSTC yet, can just build essentially a midi triggered 
>>>> flyback, to gain familiarity with the audio interfacing without the 
>>>> added complication of going strictly solid state, and the expense of 
>>>> IGBTs. Has anyone tried this? 
>>>> 
>>>> Scott. 
>>>> _______________________________________________ 
>>>> Tesla mailing list 
>>>> Tesla@xxxxxxxxxx 
>>>> http://www.pupman.com/mailman/listinfo/tesla 
>>>> 
>>>> _______________________________________________ 
>>> Tesla mailing list 
>>> Tesla@xxxxxxxxxx 
>>> http://www.pupman.com/mailman/listinfo/tesla 
>>> 
>>> _______________________________________________ 
>> Tesla mailing list 
>> Tesla@xxxxxxxxxx 
>> http://www.pupman.com/mailman/listinfo/tesla 
>> 
> _______________________________________________ 
> Tesla mailing list 
> Tesla@xxxxxxxxxx 
> http://www.pupman.com/mailman/listinfo/tesla 
> 
_______________________________________________ 
Tesla mailing list 
Tesla@xxxxxxxxxx 
http://www.pupman.com/mailman/listinfo/tesla 
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla