[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [TCML] Quick Question
HI Everyone
I am going to give you so information on EMI with Tesla coil. I
have a 1500 sq. ft. shop with
metal and solar barrier around it, which blocks everything. I work on
radio's and repair my wife's
ATM machines so I have to make sure the EMI and EMF is very low in the
shop. I went to the
local college were I teach night class's at and use there HP Spectrum
analyzer 8569 if
I remember right and there Carnel labs EMI/field meter and a hand held,
I don't remember
what it was. the first thing I did was put my O scope on the AC line at
my work bench
turn on my 4 in Tesla coil and the scope show a big spike in EMI and
noise. MY shop
is 150 feet from the power pole were the ground rod is so I put another
ground rod right
at my breaker box in the shop. The scope noise signal drop about 65%. I
still did not like
that so I took the 3 outlets in my shop tied them to a single ground
wire 6 feet from
the outlet put a 10 ft. ground rod in the ground hook everything up, try
it again this time
the signal was total clean, I tried my 6in coil still was clean, I fix
the AC side but
not the air EMI. With a one spark gap the HP show a wide range of EMI,
the EMI/field was real high up to 15 ft away. I made a wire cage and put
over
the spark gap ran it straight to a ground rod. this got rid of 65-70% of
the EMI.
I do a lot of experiments with Crooks and Geissler tube, a lot of crooks
give soft
Xray's so play with different think to stop the Xray's, one thing my
research came up
with was 1/4 in acrylic would help with the Xray's. I made a cover 3
sides made of
1/4 acrylic put wire on the two ends and did the test again, this time
it was 75% gone.
I than put aluminum tape on the inside of the acrylic but was no help,
than I used
the copper foil tape which work great I got 90% the of the EMI out of
the room
from the spark gap. ON my big Tesla coil it has 5 copper tubes in a PVC
pipe and
it seems like the EMI came more out of the top and bottom than through
the PVC
pipe itself. I try a rotary spark gap they had at the school, the EMI
was off the scale
on the analyzer and the EMI/Field meter up to 25 ft away. The most I
ever got the
EMI down was 60% with a cage, and the more gaps on the rotary the worst
it got.
The actual arc's itself did not emit a lot of EMI unless they hit the
strike rail
or my metal door than the EMI spike. I also tested this with my solid
state coil's
and there was little air EMI readings. Both my drsstc are small not
large the best
only does 2.5 ft. but I run it in the same room with my work bench and
my wife's
ATM machine on and running with no effect on them but it is being run on
the grounded
outlet too. In the end there is no way to total stop air EMI but you can
stop 90% of it coming
across the ac line for sure. I am no expert at Tesla coiling this is
just the testing I
did with the test gear I could use.
Alton
On 7/7/2013 3:24 PM, Mike Gray wrote:
Hi all, just a quick one. I was running my rotary spark gap the other day
to do some testing, and so I had a multimeter out on my bench top, fairly
close to the spark gap assembly. When I ran the spark gap the display on
the multimeter went a bit haywire - it all flashed up and started rapidly
cycling through random numbers and symbols etc. It only did this when the
spark gap was firing. Would this be due to RFI coming off the spark gap and
interfering with the multimeters internal circuitry?
Cheers
Mike
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla