locked Re: Tesla Coil help needed

Tony Fleming

Ernesto, thank you very much for your explanation! It now makes more sense
to me (as I say, in my head)! I hope I can put together some schema and
I'll see the recommended video and websites.
You have a wealth of knowledge and I'm very pleased that you explained it
to me in principle of the TC and also what the i.e. resistors do ...
I would hate to make something without understanding it well, before making
attempt to assemble it or play with it.
I'm planing to demo this for our show in early fall here in Lincoln,
Everyone, kids, young, older and old people love anything that makes sparks
and sound + lightning - that is how I draw them to my tables, where I let
them play with some of my demo units.
I like to plant the seed in their head, just like Mr. Helebrant did it in
1969, when I was about 15 years old. Now I've return the favor and get
other excited about electronics, 3D printers.....
Have a great week and thank you for your time!
Tony

On Sun, Mar 15, 2020 at 3:29 PM Ernesto <ebordon@...> wrote:

Hi Tony,

I have not forgotten about your Tesla coil you inquired in the other
thread. I have no prior knowledge on how to build such a thing, although
the principle is rather simple.
For circuit diagrams, I recommend that you google "Tesla coil circuit
diagram" and you will see a bunch of different circuit diagrams, which
give an idea of how they work.

It all starts with that metal box you had in your hand, with pins to
"input" and to "load". This can be a line filter preceding the 60 hz
step-up transformer that avoids getting the noise of the tesla coil into
Then comes the step-up transformer, in your case with a symmetrical
secondary of 12 kV, (each half or between the two ends?) which can be
safer than single-ended. This will give you 12 kV at 60 Hz that will feed
the coil.

The 12 kV secondary connects to a capacitor bank in series with the
"primary" of the tesla coil. This "primary" is what you wind with the
copper tube around the concentric tesla coil that came already winded.
The capacitor bank is built with the 16 2 kV capacitors in series, with
the many 20 Mohm resistors across these capacitors to help divide the total
voltage across the bank equally among the many capacitors in series.

So the 12 kV will charge the capacitor bank through the tesla "secondary"
to the high voltage.

What I see missing in your set is the SPARK GAP, This spark gap connects
across the 12 kV secondary, also in parallel with the capacitor bank plus
tesla "primary" in series. The purpose of the gap is short out the 12 kV
before it reaches its peak, in this way discharging the capacitor bank
through the tesla "primary' in a huge jolt of current, that induces in the
long tesla (secondary) coil the huge voltage that makes the fireworks!
(the 12 kV transformer is not affected by this sudden short because of its
large stray inductance).

Maybe you find some guidance, especially in fabricating the spark gap, in
the following video by someone who is building the tesla coil:

Have fun, and let me know how it works out and any further questions.

Regards,
Ernesto

Re: Tek 576 Curve Tracer HV Replacement Transformer

Mlynch001

Cores have arrived and the actual production work began late last week. Coils are wound, varnished, encapsulated and finally, tested. I have insisted that quality and reliability have priority speed and cost. After the final testing phase at the factory, transformers are shipping to me immediately. I will distribute the individual orders ASAP once the parts are received here. I estimate 10-14 days until I am able to mail the first components.

--
Michael Lynch
Dardanelle, AR

Type O plugin

cmjones01

I've just acquired a Type 'O' operational amplifier plugin, in good,
tidy condition apart from the lack of a few valves (the 6DJ8/ECC88s
had disappeared, of course, and a couple of 12AU6s had gone astray).
I'm looking forward to getting it working

I find the idea of being able to perform mathematical waveform
manipulation in the analogue domain fascinating, and it's certainly a
great trick for my trusty 535A to have up its sleeve.

My question is, though, why didn't the later transistorised scopes
have a similar plugin? There was the 3A8, but nothing equivalent for
the 5000 or 7000 series as far as I can tell. I can see that digital
scopes removed most of the need for such a plugin in the 1980s, but
that leaves a gap after the 500/560 series. Maybe the idea of the
operational amplifier's flexibility is nice, but it turned out not to
be so useful in practice?

Chris

TDS3000B calibration

Why am I thinking of running a calibration? The trigger point is not
indicated correctly for faster signals - if I feed it a "fast rise" pulse
from the CG551AP, the trigger point is shown at about the 2% point of the
step signal even though the trigger is set to 50%. There a few other
things that weren't quite "on the mark" that I noticed as I ran through the
Training Manual. I'm hoping a calibration will sort all this out.

Timebase though appears "spot on" which is good. Is it possible to skip
steps in the calibration - no point re-doing the timebase calibration if it
is right ...

Before I attempt to run the full calibration procedure on my TDS3000B, I
want to be sure that I can generate all the necessary signals, and that the
nature of the signals is clearly called out in the calibration process once
it starts running.

I have SG503, SG504, CG551AP, and a CG5001 (with pulse heads for the last
two).

Cheers
David

TDS3000B timebase scaling

Instead of the classic 1-2-5 steps, the TDS3000B out of the gate uses 1-2-4
which I rather dislike (though I understand why it may have been done that
way).

Is there any way to change this?

David

locked Re: Tesla Coil help needed

stevenhorii

Jean-Paul,

Yes - I am a radiologist, though now semi-retired.

My specialty uses a lot of high-voltage equipment. X-ray generators put out
120kV or more and at sufficient current to kill you, so I leave working on
this stuff to the service people. They did show me a bad x-ray tube that
was arcing - we watched it through a lead glass window. It looked like a
flash tube (a very bright one) going off.

I am sure you will respect the voltage that a Tesla coil can put out,
though the current is pretty low.

Steve

On Mon, Mar 16, 2020 at 3:23 AM Jean-Paul <jonpaul@...> wrote:

Hello all! Fine to see this. I have been doing Tesla coils since 1950s
when I was a young and foolish kid.

See old issues of "Tesla Coil Builders Association" back to 1980, by Harry
Goldman. Available as PDF and printed issued on epay.

The most knowledgeable Tesla maven today is Greg LEYH, see LOD.ORG, for
the largest Tesla Coils ever.

Beware that neon sign transformers, plate transformers and charged HV caps
can deliver a LETHAL shock.

Finally the machines when in operation emit copious amounts of noise,
ozone, UV light and RF, which can have bad effects on your vision, hearing,
lungs and the RF can disrupt or damage lots of electronics.

Just the ramblings of an old retied EE!

Enjoy and be safe,

Jean-Paul

PS: Is the last post from Steve H the X ray man?

Re: Scope Cameras

Brian

Hi , the PCX200 card that I currently use is a PCI card , probably still obsolete but fits in a more up to date pc.The polaroid film I nearly always used was the 665 as it had a negative as well , the 107 was used when I wanted to push the speed to its max for something very fast and likely single shot . The camera being only B/W is no problem as the films used were also .These days I have a TDS744 and hardly ever need the cameras .
Brian

On Monday, 16 March 2020, 02:59:14 GMT, Chuck Harris <cfharris@...> wrote:

The nice thing about the C1001/C1002 cameras is you
can sub out the original camera for something good.

Which you may as well, as the frame grabber cards
were all long obsolete ISA cards, that were separated
from the cameras when their PC's got scrapped.

-Chuck Harris

Brian via Groups.Io wrote:
Hi , for a scope camera I use the C1001/C1002 cameras along with a CORTEX PCX200 frame grabber , it can also provide the 12v for the camera , the s/w for that may still be on their website .This camera is a video camera and the frame grabber allows getting a 'still' from the data stream . The frame grabber can be triggered much like a still camera and this is ok as long as the sweep rate is not fast .I pursued the Polaroid film path to be told by the new producers of the film that the production tools for the type 107 and the 665 film packs had not been saved after production ceased and they were not able to produce anything as a result , and may never as it would mean starting from scratch .

Brian

Re: Tektronix Probe Tips DIY

Tom Gardner

Similar techniques can be extended to add a low-inductance ground bayonet/spear to a probe, as found in the HP10020 1.5GHz passive resistive divider probe:
https://www.eevblog.com/forum/testgear/fifty-ohm-probes/?action=dlattach;attach=135831;PHPSESSID=lohekcsu194l3qpirrh4ps38p2
or the hp10431 "high" impedance passive probe:

Suitable materials are Shapeways' nylon (slightly flexible), or DirtyPCB's SLA (smooth high resolution). The latter is stunningly cheap, but takes a while to arrive.

On 16/03/20 02:45, Harvey White wrote:
One of the major problems with both Tektronix and HP probes is frequently the lack of tips. I do digital logic work, and after quite a while I managed to find a pair (both different) Tektronix tips which terminate in a wire with a connector suitable for a 0.025 inch (standard wirewrap) pin.

I got tired of not having more. I looked at Mouser (where I could find the equivalent ground leads for 5 mm diameter Tek & HP probes), I looked on Ebay. Nothing.

So I decided to see what I could do on my own. The average female/female jumper cable (available cheaply on Amazon or Ebay) fits well enough over the probe tip, but the piece of plastic is a bit harder (read impossible) to find.

Fortunately, I do have a 3D printer. So you start with a cylinder, hollow it out enough to fit over the ground barrel of a 5.0 mm probe, put a square hole in it to hold the one pin connector plastic for a female dupont connector, taper the tip, and make a through hole that’s large enough to allow the connector (minus plastic) to fit through. Do that, push the plastic on one end into the cap, put the plastic part back on, and then you have a probe tip that allows you to put the tip on a standard 5mm probe.

If the connector for the probe tip has a limited life, the jumper wires are quite cheap. You could also put one in for a female to male and connect directly to a breadboard.

If anyone wants the .stl files, please email me. I’ll also give you the .scad files if you wish. This is available for non-commercial use. I’m not posting the files here since anything posted becomes the property of groups.io.

Harvey

locked Re: Tesla Coil help needed

Jean-Paul

Hello all! Fine to see this. I have been doing Tesla coils since 1950s when I was a young and foolish kid.

See old issues of "Tesla Coil Builders Association" back to 1980, by Harry Goldman. Available as PDF and printed issued on epay.

The most knowledgeable Tesla maven today is Greg LEYH, see LOD.ORG, for the largest Tesla Coils ever.

Beware that neon sign transformers, plate transformers and charged HV caps can deliver a LETHAL shock.

Finally the machines when in operation emit copious amounts of noise, ozone, UV light and RF, which can have bad effects on your vision, hearing, lungs and the RF can disrupt or damage lots of electronics.

Just the ramblings of an old retied EE!

Enjoy and be safe,

Jean-Paul

PS: Is the last post from Steve H the X ray man?

Re: Scope Cameras

Jean-Paul

Bonjour Robin:

I had many TEK cameras circa 1980s..1990s and use 7000 series and 2465/7B.

I used my compact Panasonic Lumix LX-5 and LX-7 at fiorst in macro mode.

I took the most basic camera, with the blue plastic housing fitting the 7000 bezel, removed the back and other parts and placed gaffers black tape to mask the rear opening.

The distance for camera to CRT is 4 1/2 ", exactly right to allow a full screen shot in macro mode.

Finally with the advent of great mobile phone sensors and apps, I use iPhone 7, etc.

You must get the intensity and sweep rate adjusted and leave the camer on long shutter, I have ASA+800.

You can see the results if you search my previous posts eg re transient response.

Bon Chance,

Jon

Re: Scope Cameras

Glydeck

Here is what I came up with using a C-12 body I picked up cheap.

http://glydeck.blogspot.com/2011/03/motorola-mystery.html

George

On Mar 15, 2020, at 10:02 PM, Ed Breya via Groups.Io <edbreya=yahoo.com@groups.io> wrote:

I think I've mentioned before, that I've rigged up old C-5 scope camera carcasses with "modern" USB webcams and such, over the years. You just have to delete the original Polaroid camera back and lens, and figure a way to mount a new video camera head in its place. In more recent times, I prefer to use cell phone cameras instead.

I have some C-5s that I had planned to make into holders for cell phones, such that the optics land in the right place and focus point. With the right mechanical arrangement, it can be set up so the phone just rests on a shelf type thing that aligns it, and blocks out background light reflections from the screen. I haven't built any yet, but in the meantime, I have had decent results - enough to get the message across - with totally open freehand screen shots on a phone camera. The trick is to take plenty of shots from slightly different positions and lighting, then sort them out to find an acceptable one. Some may be defective due to timing issues between the scope trace and camera scanning rates, leaving blank spots and other distortions, but with enough shots, it isn't too hard to find a good one. This does not work with single-sweep traces though, unless maybe the camera can be set up for it somehow.

Ed

Re: Scope Cameras

Ed Breya

I think I've mentioned before, that I've rigged up old C-5 scope camera carcasses with "modern" USB webcams and such, over the years. You just have to delete the original Polaroid camera back and lens, and figure a way to mount a new video camera head in its place. In more recent times, I prefer to use cell phone cameras instead.

I have some C-5s that I had planned to make into holders for cell phones, such that the optics land in the right place and focus point. With the right mechanical arrangement, it can be set up so the phone just rests on a shelf type thing that aligns it, and blocks out background light reflections from the screen. I haven't built any yet, but in the meantime, I have had decent results - enough to get the message across - with totally open freehand screen shots on a phone camera. The trick is to take plenty of shots from slightly different positions and lighting, then sort them out to find an acceptable one. Some may be defective due to timing issues between the scope trace and camera scanning rates, leaving blank spots and other distortions, but with enough shots, it isn't too hard to find a good one. This does not work with single-sweep traces though, unless maybe the camera can be set up for it somehow.

Ed

Re: Scope Cameras

Chuck Harris

The nice thing about the C1001/C1002 cameras is you
can sub out the original camera for something good.

Which you may as well, as the frame grabber cards
were all long obsolete ISA cards, that were separated
from the cameras when their PC's got scrapped.

-Chuck Harris

Brian via Groups.Io wrote:

Hi , for a scope camera I use the C1001/C1002 cameras along with a CORTEX PCX200 frame grabber , it can also provide the 12v for the camera , the s/w for that may still be on their website .This camera is a video camera and the frame grabber allows getting a 'still' from the data stream . The frame grabber can be triggered much like a still camera and this is ok as long as the sweep rate is not fast .I pursued the Polaroid film path to be told by the new producers of the film that the production tools for the type 107 and the 665 film packs had not been saved after production ceased and they were not able to produce anything as a result , and may never as it would mean starting from scratch .

Brian

Tektronix Probe Tips DIY

Harvey White

One of the major problems with both Tektronix and HP probes is frequently the lack of tips. I do digital logic work, and after quite a while I managed to find a pair (both different) Tektronix tips which terminate in a wire with a connector suitable for a 0.025 inch (standard wirewrap) pin.

I got tired of not having more. I looked at Mouser (where I could find the equivalent ground leads for 5 mm diameter Tek & HP probes), I looked on Ebay. Nothing.

So I decided to see what I could do on my own. The average female/female jumper cable (available cheaply on Amazon or Ebay) fits well enough over the probe tip, but the piece of plastic is a bit harder (read impossible) to find.

Fortunately, I do have a 3D printer. So you start with a cylinder, hollow it out enough to fit over the ground barrel of a 5.0 mm probe, put a square hole in it to hold the one pin connector plastic for a female dupont connector, taper the tip, and make a through hole that’s large enough to allow the connector (minus plastic) to fit through. Do that, push the plastic on one end into the cap, put the plastic part back on, and then you have a probe tip that allows you to put the tip on a standard 5mm probe.

If the connector for the probe tip has a limited life, the jumper wires are quite cheap. You could also put one in for a female to male and connect directly to a breadboard.

If anyone wants the .stl files, please email me. I’ll also give you the .scad files if you wish. This is available for non-commercial use. I’m not posting the files here since anything posted becomes the property of groups.io.

Harvey

locked Re: Tesla Coil help needed

stevenhorii

This article on the Web has very good explanations of the parts, their use,
and safety considerations:

https://www.teslacoildesign.com/construction.html

Sorry if you've already seen this.

Best of luck with it.

Steve

On Sat, Mar 14, 2020 at 12:18 PM Tony Fleming <czecht@...> wrote:

I have a Tesla Coil kit but I don't have schematics that I can follow. All
my parts are mentioned in my video:
Or go to https://tonysfun.com/ and click on My Youtube Videos button.
I'm not an expert, but I take lots of precautions and use Variac
Transformers and Isolation Transformers, among other steps to be safe.
I've built Jacob Ladders from Microwave Transformers and others, like in
the video, that is for Neon Lights.....
I've tried for several month to contact people on youtube and other
places, but many of them are older videos and I don't even know if the
people are still around or using the youtube at all....
The seller mentioned in the video doesn't answer their phone and no option
to leave a VM either.

If you know of anyone or any place that can help me with this project, I
would appreciate it very much.

Re: Scope Cameras

Brian

Hi , for a scope camera I use the C1001/C1002 cameras along with a CORTEX PCX200 frame grabber , it can also provide the 12v for the camera , the s/w for that may still be on their website .This camera is a video camera and the frame grabber allows getting a 'still' from the data stream . The frame grabber can be triggered much like a still camera and this is ok as long as the sweep rate is not fast .I pursued the Polaroid film path to be told by the new producers of the film that the production tools for the type 107 and the 665 film packs had not been saved after production ceased and they were not able to produce anything as a result , and may never as it would mean starting from scratch .

Brian

On Sunday, 15 March 2020, 23:21:34 GMT, John Williams <books4you@...> wrote:

I have a Tektronix video camera that mounts directly on the crt the same as the Tek still Polaroid cameras. There was a camera for sale on eBay a while back, all that is required is a “brick” to supply power to the camera. I believe Dennis Tillman made a still camera mount for this purpose.

Re: Scope Cameras

John Williams

I have a Tektronix video camera that mounts directly on the crt the same as the Tek still Polaroid cameras. There was a camera for sale on eBay a while back, all that is required is a “brick” to supply power to the camera. I believe Dennis Tillman made a still camera mount for this purpose.

Re: Scope Cameras

Harvey White

Haven't done much more than to consider the idea.

However, my experience is with canon EOS products.

Canon EOS stuff is apparently worth *nothing* when a new model comes out (I certainly couldn't get much for a 60D when I bought a 70D).

So any of the older canon models should be a starting point.

I'd be tempted to use a canon 10D (not sure when that's going to happen yet), but it takes a 2.5 mm phone plug to trigger it.  I'd think that some minor electronics slaved to the Tek scope camera electronics (haven't looked at that yet but I'd consider it strongly).   I'd want to consider a 50mm lens with an extender, make sure that it carries the signals with it, and then rework the scope camera back (and lens, sadly, and likely the electronics) to get a decent coverage.  I would not expect the existing lens in the scope camera to work simply because of the distance between the focal plane and the lens.  Since the original camera used a standard shutter and the canons use a focal plane shutter, expect a few differences there.

I'd think that a standard camera with a remote release, a few bits of electronics to control the shutter, and a lens extension tube might just get the job done.  IF you can do this with a phone, or a point and shoot, that's good.  Haven't played with that although I could.  An advantage of the DSLR is that if you can dig live video out of them, then you have a way of getting straight video off the scope screen into a monitor.

Just ideas, though.

Harvey

On 3/15/2020 3:31 PM, Robin_Birch wrote:
All,

I'm currently playing around with the Scope Hood models that were recently
posted on here (Thanks Michael). I'm starting to think about extending
these to make a modern scope camera, Polaroid film packs being made out of
pure unobtainium.

Has anyone got any experience of different digital cameras that would be
suitable: Electric release, able to extend exposure to max sweep on a 4
channel scope plus data painting, able to reduce exposure to fastest
position, plus any other frills that people can think of that are necessary.
The body would have to be suitable to mount on a hood, or possibly within
one. The lens would have to be able to focus down to a reasonable distance
and have a zoom that was adjustable to frame the screen.

Ideas anyone?

Robin

PS: I'd probably be putting this on a 7000 or a 468.

Re: Scope Cameras

greenboxmaven

Polaroid film is not going quietly into the darkness. There are continual requests from photographers to re-open production of the peel apart film packs, there is a single photo single use cartridge for Polaroid pack cameras available from Austria but it costs almost \$10.00 per exposure. The dual seperate roll film for the older cameras has not been made for over 25 years, there are also continual requests for it to be produced again. Adapting phones or digital cameras is one possibility, but depending on the speed of the sweep a real photograph is still the best. Analog photography is rebounding in popularity, and Polaroid has been bought out by another company that is making film for some of the cameras. Fuji refused to continue making Polaroid peel-apart packs, the pressure on the new Polaroid company to produce them again is intense. Whether these requests will be considered worthy is unknown. Fuji does make several instant cameras, their Instax series. The cameras are in production and easy to buy, the film packs usually cost about \$1.25-2.00 per exposure. The film is very fast, ASA 800, so getting the exposure correct would require filters and alterations to the shutter. New Polaroid cameras and their film packs are easily available and not too expensive, but the same sort of filtering and shutter modifications would be needed. It could be interesting to get home brew photography mavens involved. The good thing about all of this is that scope traces are very bright, so less sensitive photo media could be used.

Bruce Gentry, KA2IVY

On 3/15/20 3:31 PM, Robin_Birch wrote:
All,

I'm currently playing around with the Scope Hood models that were recently
posted on here (Thanks Michael). I'm starting to think about extending
these to make a modern scope camera, Polaroid film packs being made out of
pure unobtainium.

Ideas anyone?

Robin

PS: I'd probably be putting this on a 7000 or a 468.

Re: Scope Cameras

Hadn’t thought of a phone. Was thinking more along the go pro sort of thing. Hmmm, have to think about that

Cheers

Robin

On 15 Mar 2020, at 20:05, Mlynch001 <@mlynch001> wrote:

﻿I have already built a prototype that uses an I-Phone to take pictures. I have not done enough with this to answer most of these questions. The I-Phone does a presentable job. It can be done with some additional work.

--
Michael Lynch
Dardanelle, AR