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

Re: Rotary Sparkgap


>> Malcolm,
>>         Has anyone plotted an IV curve for a shunt limited xformer? I know
>> just enough transformer math to be dangerous, but my gut feeling is that
>> they are not linear at lower currents.
>> 
>>                                                 jim
>Jim, that's a good point you raise. I WAS looking at it from the POV 
>of a limited transformer. It's more likely that it's a pole pig with
>those specs and therefore limited only by external inductance hung on 
>the primary. It may be that the 500mA is the maximum that can be 
>drawn without blowing a fuse. If so, my crude impedance calc may not
>be valid. It may be that a v. small cap could be charged far more 
>often than I suggested.
>    And yes, I think you may be right about the I/V linearity of a 
>neon. Only one way to find out - I'll try some measurements on mine
>this weekend and post.
>
>Malcolm
>
The reason I brought this up is, back when I was playing with my Xenon lamp
ignitor xformer(last week) which is shunt limited like a neon, I found that
connecting a milliamp meter accross the output produced no current! Even
down to the microamp level, yet when I introduced several hundred to several
thousand ohms as a load I could measure current. I finally decided that it
was a 20ma transformer. Since I bought my neons monday, I've been to busy
building a new spark gap and sparking and arcing to plot an IV curve for the
neon.

Remember last november when I came upon these news groups and I was planning
to drive my TC with 50 or so watts! I've cought the bug or should I say it's
cought me. I was hooked when 2' of air discharge came off my 28"x3" torroid
straight at me and then I saw a white arc over to my wife's bike. 20"
straight line distance on only 7.5Kv -at- 60ma.  Thank you for the Q
measurements that hooked me. I haven't had this much fun in years!


                                respectfully,

                                jim fosse