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Messages - Mads Barnkob

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1
Dual Resonant Solid State Tesla coils (DRSSTC) / Re: Futurist's DRSSTC 0.5
« on: September 21, 2021, 07:21:50 PM »
A really clean build and similar to one that I have planned to do a video about as well :)

Time flies, so its also about a year ago that I bought secondary coil and toploads from highvoltageshop.com, so thanks for sharing the 3D parts, I can properly use those aswell! I am not an expert on laser cutters and 3D printers, but can the files for laser cutter be converted easily to 3D print?

I did however order the Dan/prof9dc double TO-247 full-bridge boards and drivers instead, so still have to populate those and I think I will scavenge IGBTs out of old equipment.

I might as well make it with a bigger MMC the first time, I dont want to run out of primary turns. :)


2
Electronic Circuits / Re: Tandberg TT1200 DVB MPEG-2 Decoder Teardown
« on: September 12, 2021, 06:42:03 PM »
Would it be worthwhile to extract the power supply (s) for bench use?

I left the power supplies in the enclosures, as that makes it a good ready made part with mains plug, filter, earthing and it all.

Thanks for sharing your unit Michael, as I mentioned in my video, the conversion from analog to digital was such a huge market, everyone jumped in and making it cheaper was just more profit :)

3
Electronic Circuits / Tandberg TT1200 DVB MPEG-2 Decoder Teardown
« on: September 11, 2021, 02:30:48 PM »
Teardown of some old and discarded DVB MPEG-2 Decoders that have been used in a large buildings distributed TV network. Despite that units look the same on the outside, they turned out to be very different hardware revisions on the inside.

/>

The front of the Tandberg unit only has a display and 4 input keys. At the backside there is coaxial signal input, card reader, RS232, audio and video outputs.



The old unit is built up with a mainboard that has a connector for a backplane, on which 4 cards are mounted. The newer Tandberg has a main CPU, which is a Xilinx XC4013 FPGA with a 27 MHz crystal sitting next to it. The C-CUBE AViA-DMX provide one end of a highly integrated MPEG-2 transport chipset. The STi3520ACV is a MPEG Audio / MPEG-2 Video Integrated Decoder. All the following cards are just made into one board on the newer units.



The power supply is pretty standard on the input in the right side of the picture. Bridge rectifier with common mode noise filter, capacitors and a fuse. The primary side of the transformers are driven by single transistors, which sit on a live heat sink! The output seems to be at-least two different voltages, red/black is the high power main source and the other 3 are likely 2 different lower voltages for different CPUs.



The input signal card has its own dedicated 7805, 5V regulator with a large heat sink. The shielded analog-to-digital ADC conversion goes into a unknown Philips IC with a 16 MHz and 61 MHz crystal sitting next to it. The VLSI VY27065 is a Satellite DVB IC of unknown function and the VLSI VES5453 Satellite FEC COMATLAS is a Forward Error Correction Decoder.




Besides the cardreader plastic enclosure, the large IC really stealing all the attention here is the DiviCom DMX-2000+  MPEG-2 TRANSPORT DEMUX IC. There is also a Xilinx XC3142 FPGA with 27 MHz crystal and a good oldschool Motorola MC68ECO20 microcontroller which most likely runs the very old cardreader software. The amount of different MPEG-2 decoders in this products makes me think that a lot of jobs are done twice or three times, in different places, instead of treating all data in a central CPU.



The output card has two  Xilinx XC3142 FPGAs near the backplane connector. The  STi3500ACV is only a video decoder IC, unlike the 3520 we saw above that is both video/audio. The Texas Instruments TMS320AV110 MPEG audio decoder supports all ISO-MPEG audio decompression algorithm. The audio output is served by a Philips TDA1305T, where you can almost always recognize a audio IC by the TDA start, its a stereo 1fs data input up-sampling filter with bitstream continuous dual DAC (BCC-DAC2)


4
Laboratories, Equipment and Tools / Re: Updated tour of my workshop
« on: September 11, 2021, 08:02:10 AM »
Great to see a heater in the workshop, I wish mine had enough insulation for it to make sense to have a heater. As its next to our house, it gets enough heat that it can barely stay at 0 to -1 degree Celsius, when we had -15 degrees Celcius last winter.

The place where you do your thinking, is also where you have the fire extinguisher  ;D

I did not see your vacuum cleaner, but it must be somewhere with such a tidy shop!

How about your ceiling lighting fixtures? Is it fluorescent or LED? I never regretted putting up a lot of LED fixtures.

5
I have only seen it used once, to parallel two individual full-bridges, instead of just running them in parallel, they were joined by matching transformers. Not quite a coupling transformer, but almost :)

Pictures of "Resonant Rise" by Roy Piepers / Dalus: https://www.flickr.com/photos/roypiepers/sets/72157626495926316/

A few words on it from Dalus: https://4hv.org/e107_plugins/forum/forum_viewtopic.php?p=1&id=116077


6
I wrote about some known DIY methods for that in another thread: https://highvoltageforum.net/index.php?topic=473.msg2959#msg2959

7
Solid State Tesla Coils (SSTC) / Re: SSTC - blowing up transistors problem
« on: September 06, 2021, 03:20:30 PM »
Hi,
I try to build Mads's Tesla coil (SSTC II), but i have a problem with it. Coil works fine at lower voltages at brigde but when i raise voltage to around 100V DC transistors Q3 and Q4 die. It happened 3 times already, always Q3 and Q4, they are cool so it's not overheating. I thought that EMI might mess with something in circuit so i made quite big metal box which i use to cover everything, even transistors. There is also a barrier inside box between transistors and rest of circuit including GDT and other parts. Box and bottom terminal of coil is grounded to metal rod outside house (it's not connected to mains, wire used to connect those points is short, it has 4-5 meters). I use a filter between mains and autotransformer. I'm sure that GDT phasing is fine, i always check it with osciloscope.  I also test my circuit using 500W heater as load instead of coil because this way EMI is much smaller and i can do some measurements without problems. I use 555 timer circuit to turn on drivers, this signal has around 120kHz and 55% duty cycle(i know it's too small frequency but i didn't have other resistors).

The purpose of the 555 timer is to only give a interrupter signal at 1-500 Hz! The antenna feedback gives the secondary circuit resonant frequency to the drive frequency.

I noticed that when i turn on my circuit without voltage on bridge the signal used to control gates of transistors is perfectly fine and square but when i start to raise voltage there appear some oscilations (on the photo). It doesn't look good in my opinion because voltage spikes are something around 18V, but it's not the worst thing. When i look at voltage on the heater it looks similar to signal on gates of transistor but for example at 100V DC those voltage spikes can reach 250V (i don't have photo of this). Despite this transistors survived 320V with heater as load and didn't blow up. If it matters i have other diodes on bridge because i didn't find those MURs, and i used "dsep15-06b". I also have 13 turs on GDT instead of 15 and 9,4 Ohm gate resistors.
I noticed that when i raise voltage using autotransformer frequency of sparks decreases  without even touching interputer's potentiometers, is it normal? For expample at 50V coil makes few sparks per second but at 80V it makes one spark for few seconds. I thought that power supply used was too weak because it was 12V 1,7A and fans need around 1A, so when i regulated potentiometers for max frequency of sparks i could hear that voltage drops because fans were spinning a bit slower. To be sure next time i will use ATX power supply but now i'm waiting for delivery of new mosfets. What do you think about it?

Photos:
https://mega.nz/folder/Niwi0Cob#0xoSJtAtqv4BYtNhkq52eQ

Are your MOSFETs insulated from the heat sink? Sounds like you are short-circuiting your supply, which results in a large voltage drop.

8

Great run! and that amount of DC bus capacitance is going to give a show if you explode and IGBT :)

So keep the cameras rolling! You have the rock and roll attitude of Tesla coiling with "enough material will be vaporized that it stops arcing over in that corner."  8)

Your secondary is much much wider than I first thought, its easy to read a measure and imagine something, but your new pictures of standing next to it....

Probably inevitable that I blow an IGBT eventually, hopefully not for a few years though!

Lol, she's a girthy beast for sure! Hard to gauge the actual size of the coil without any point of reference.

 I really need some easier way to get it higher off the ground, the stand I built is nearly impossible to get the coil on alone. I think it would really help horizontal spark length.

You look to be working out quite a bit more than I do  ;D I can barely lift my secondary coil in place alone, in a safe manner where I would not scratch it, so my large coil is also too big for a single person to manipulate beyond its original physical dimensions. I have thought about making a base, in a distant future, that would be ready-made for a cheap motorcycle scissor lift like this: https://www.expondo.dk/msw-sakselift-mc-150-kg-10060972 or something similar, it would properly need a bigger foot print for stability.

9

Wow, that is a fantastic looking coil, great job on the construction! The adjustable coupling is a great idea, would have been great to have on my coil. Maybe I will do something along those lines on my next build.

For now, I'm not too worried about the arcover on the frame. It does melt some of the aluminum, but it is not serious enough to compromise the structural integrity of the frame, and it does seem to fizzle out after arcing over for a few seconds. I figure that it will either become carbonized/oxidized enough or enough material will be vaporized that it stops arcing over in that corner.

Great run! and that amount of DC bus capacitance is going to give a show if you explode and IGBT :)

So keep the cameras rolling! You have the rock and roll attitude of Tesla coiling with "enough material will be vaporized that it stops arcing over in that corner."  8)

Your secondary is much much wider than I first thought, its easy to read a measure and imagine something, but your new pictures of standing next to it....

10
Voltage Multipliers / Re: Marx v. CW
« on: September 05, 2021, 08:30:16 PM »
I've been assuming that CW multipliers are superiod to Marx, in part because the Marx spark gaps need to be adjusted and can't be run under oil.  It seems like an open SG is a crude switch as compare to diodes.

What am I missing?  If one's goal was to produce the most spectacular arc, and money weren't too much of a limitation, which type would be better?

Let the wars begin!

The Marx generator is a super simple/cheap way to achieve a very high voltage pulse discharge with the fewest part possible. It is capacitors charged in parallel, discharged in series.

A CW multiplier is a high voltage DC circuit, it requires a lot of parts and is more complex/expensive.

The use-cases for Marx and CW is not the same. A Marx generator will give you the most impressive and LOUD sparks for the least money. A CW will give you very long, high ozone producing and corona discharge sparks, but will also cost more and take longer time to build.

11
Dual Resonant Solid State Tesla coils (DRSSTC) / Re: What is BPS?
« on: September 05, 2021, 08:25:30 PM »
Hello, i was out of the forum because my pc had broken down, and i had to buy a part that took too long to arrive.

So my first question is: what is the best BPS range for the tesla coil to play music (I was thinking something like 100BPS to 400BPS)?

I'll ask more questions as these are answered, because I don't fill up with questions.

thanks you for the patience.

The question does not make sense. There is no best BPS, the BPS or Hz is just the frequency of your interrupter signal.

You can design your coil to withstand higher BPS/Hz, by designing it to withstand higher RMS current and better thermal handling.

12
well, the result is correct at 200Vdc (maxi 350VDC) with this new coil.

I would like before going to higher voltages to adjust the OCD to the driver UD2.7C

the full bridge is composed of 4 IGBTCM200DU-12F (600V 200A). The current sense for OCD on the primary is 1: 2000 also the same 1:2000 to feedback

At which voltage to adjust TP1, how to calculate it ?

is somebody can help me ?

A 1:2000 ratio current transformer corresponds to 2000A in the wire going through the CT, gives 1A in the CT output. So the voltage output depends on the burden resistor across the CT output. Too little resistance might give too low voltage, too high resistance gives unwanted phase shift. A normally used value is 5-50 Ohm depending on number of windings. So if you need 5V for 2000A primary coil current (1A output from CT), that is just Ohms law to get the required resistor. R = 5V / 1A = 5 Ohm. So if you want to set the OCD to 500A, 25% of 2000A, set it to 25% of 5V ~ 1,25V. Be sure to check what the OCD range of the driver really is, I seem to recall that the effective input range of UD1.3 was only something like 1-3.75V. But that might be different for UD2.7C

13
Some new heavy weight members! I hope you find all the help your need for your Tesla coil building here, you certainly have the background in place, let us help you with the rest :)

14

Quote
Maybe a settings button underneath each coil activate button instead?
The double outlined buttons are used in more places. For that reason it‘s explained on the Help and Info page. I thought about showing that one the first time Syntherrupter‘s started but never got to the implementation.
I could for sure add separate buttons in every case but it would make the UI quite a bit more complicated and probably much less clean (this is especially true for the Coil Settings page which is pretty well filled).

Quote
I would also wish for a "midi signal" status blinker on the live midi mode page, just for trouble shooting between pc, syntherrupter and output modules. It would also give some more life to the very static page, when playing MIDI, you got no idea if its playing or not :)
I know the UI is very static. This is because the Nextion commands for controlling the UI from the Tiva sideare quite expensive (string based). With the buffered outputs and an optimized serial library I might get it to work. However, I‘d much prefer tossing out the Nextion protocol entirely and replacing it by something custom. Both cases require quite some work to do so it‘s not for anytime soon. Actually, getting live readouts was a feature I planned for Syntherrupter 2 only. We shall see…
Til then I‘d suggest to just hook an LED (with resistor) between 3.3V and the serial line.

At this point I realize a little troubleshooting guide could be nice. Here‘s the thing with hairless MIDI Serial: there‘s only one case I‘ve ever seen where it doesn‘t work and that‘s when the serial port disappears for some amount of time or becomes unavailable (f.ex. disconnect and reconnect the cable) in that case it still shows it‘d send stuff but if you disable and reenable the serial bridge you‘ll see that it actually doesn‘t send anything to the port. You need to restart it.
Other than that you can be about 99.x% sure that if hairless midi serial shows it sent data to Syntherrupter, it did - and Syntherrupter actually received it.
Btw in hairless midi serial you can activate the logging window and see what midi commands are sent to the port. Can be handy.

Thanks for the clarifications. It all makes sense and it was just suggestions based on what I see. Its a complex software you have put up and even with the good wiki, we are not inside your head :)

Quote
I guess I can just contribute to the documentation on github? I think the PC MIDI setup chapter that you put out in the "front" readme, needs some more integration into the main documentation.
Any contribution is more than welcome! :)

I tried my first github contribution, which also explains why you were after me for not writing a comment. I was not quite aware if it was submitted without pull request? This is my first time using github, so bare with me. I wanted to try something simple before editing large parts of the wiki.

Quote
All channels activated for all coils as default, also had me confused, because that sounds very weird and wrong the first time you just try to play a midi. Maybe add new defaults that is just channel 1 to coil 1, 2 to 2 etc.?
I had my 4 mini teslas play the same channels now a couple time; didn‘t sound weird and wrong to me…? Or did you just forward all channels to Syntherrupter? In a complex MIDI file this is likely way too much (and would explain your description). However, that‘s not a good idea to begin with. You should only pass the channels to Syntherrupter you want it to play. There‘s no point in loading it with additional channels that are „muted“. Even if they‘re not audible Syntherrupter needs to keep track of all the volume, pitchbend, envelopes, etc in case you activate the channel again.
That aside I wanted to have a configuration that‘s guaranteed to work - for which I really can’t see an alternative. I‘d expect many more people to be confused if one channel works and another one doesn‘t (f.ex. chn 1 and 13).

You are right, I just loaded up a MIDI and pressed play. Break-the-build testing style! Maybe there is more to it, I do not have a video of this: deselect all channels for coil 1, select channel 1, press next, deselect all channels for coil 2, select channel 2, press next. Do this for all 6 coils. At the 6th coil, pressing next showed me coil 1, but with channel 16 selected as the only. Pressing next now showed coils 2 with 15, 3 with 14 and so on. Getting to the 6th coil and pressing next showed me channel 1 for coil 1. IS there really 12 pages or 6 pages? I can not see any difference, but the number of configured channels... :-[

Quote
Did I miss the "omni-mode" somewhere? I thought it could auto-assign midi channels according to active coils and also just randomly choose them? I might remember completely wrong.
The stereo mapping features - which includes omni mode - is really the most hard to use feature of Syntherrupter*. First of all, omni mode only makes sense if you have stereo enabled. Quick recap: in stereo mode, every note has a position on the stereo scale. Every coil has a position, too, and it only plays the notes within its reach. Syntherrupter got a couple festures for making melodies move around across the stereo range (and thus across different coils) but you don’t always want that. Since every note has a precise position, you can’t really play it on multiple coils equally anymore. That’s where omni mode enters the game: if a MIDI channel is put into omni mode it doesn’t have a stereo position anymore but is „everywhere“ - thus can be played by all coils „normally“ again (as if no stereo stuff was enabled).
This probably sounded way more complicated than it is so let me try to do a tldr: omni mode disables stereo mapping for a given channel. That‘s it.

*that‘s because there‘s no easy to use UI or tool for it. You have to embed the raw commands into your MIDI file or send them to the MIDI port. With Synthfont it‘s actually not too hard to embed the commands but I understand that‘s a too steep lesrning curve for most people.

Thanks for cutting it out in paper, I will leave it be until I master the other parts :)

Quote
I will admit that the learning curve seems steep, especially with SysEx, envelopes and such, but I hope it will soon make more sense and the prepared midi files on PC for a certain coil setup can just be played and all settings for the coils, channel assignment and such is in the files.
Syex might be a lot to begin with but when you‘re using Syfoh (and it‘s really the only practicable way to use sysex), it‘s basically just a command line interface for Syntherrupter - no more no less.
As for the envelopes I have to admit I really can‘t figure out what‘s so hard about using it. I‘m not talking about making your own envelopes or understanding how the envelopes themself work. I‘m just talking about the „high level“ concept of „you can change the instrument“ from „pizzicato strings“ to „piano“ or „electric guitarre“ or „slow strings“. The only confusing thing here is that syntherrupters instruments don’t match the instrument names in pretty much any MIDI player (syntherrupters piano sound f.ex. is MIDI program 10, called Music Box). Maybe someone can help me understand the issues better; I‘d really like to.

Don‘t mind about embedding the sysex commands into your midi file. I mean, yes, it could be done but the advantage over a simple text file that Syfoh sends to Syntherrupter is close to none - and much easier to use and modify at the same time.

Edit: as an example I attached such a sysex batch file which did the entire setup of Syntherrupter for playing my Final Countdown MIDI file (I just power on Syntherrupter; no interaction with the touchscreen is required). All it takes is one call of Syfoh.py and I'm ready to go. Ontimes, channel assignments, stereo positions - everything.

Windows command line for running Syfoh (sending all the data to MIDI port nr. 1 which happens to be loopmidi)
Code: [Select]
python Syfoh.py -m mid -p 1 -i "D:\Syntherrupter Setup for Final Countdown.txt"
Content of the text file:
Code: [Select]
### Syntherrupter Sysex commands for mini orchestra
### Final Countdown.

# Setup stuff
set ui-update to manual
set mode-enable for mode all to 0
set coil-buffer-time to 10000

# Coil settings and limits
set coil-max-duty for coil all to 0.2
set coil-min-offtime for coil all to 0
set coil-min-ontime for coil 1 to 40
set coil-min-ontime for coil 2 to 15
set coil-min-ontime for coil 3 to 35
set coil-min-ontime for coil 4 to 10
set coil-midi-voices for coil all to 16

set duty for mode midi-live and coil all to 0.03
set ontime for mode midi-live and coil 1 to 200
set ontime for mode midi-live and coil 2 to 300
set ontime for mode midi-live and coil 3 to 200
set ontime for mode midi-live and coil 4 to 200

set mode-enable for mode midi-live to 1

# Distribute 4 coils across the stereo range
set midi-pan-cfg for coil all to linear
set midi-pan-reach for coil all to 0.333
set midi-pan-pos for coil 1 to 0.0
set midi-pan-pos for coil 2 to 0.333
set midi-pan-pos for coil 3 to 0.667
set midi-pan-pos for coil 4 to 0.999

# Assign channels to outputs
set coil-channels for coil 1 to 0b00011000000
set coil-channels for coil 2 to 0b00010000001
set coil-channels for coil 3 to 0b00010000010
set coil-channels for coil 4 to 0b10010000000


Kind regards,
Max

Envelopes itself was only confusing, because I thought I had to configure them on the Syntherrupter. I understood it fine with names not fitting, but that it was instrument 0 to envelope 0. Part of this is also from just playing a MIDI without preparing channels, instruments or anything, as I wrote above. The demonstration in my latest project video should show it better? Did I explain it as it was intended to work?

Your syfoh sysex examples are great! From looking at the sysex documention, you should really add these examples, again it looks rather complex from all the formatting and explanation of the sysex package. Which confused me a bit before finding the tiny link to syfoh, that should be the first link in bold right after sysex headline :)

Bummer about your show and coils exploding, any graphic pictures to show in your DRSSTC thread?

You will properly fix all your bugs before I finish the 19" rack case, "only" projects left after audio inuts, safety and power supply.

15
In this video I mount, update and test the Syntherrupter with its MIDI capabilities and gives a walk-through on how I am using it. Some of the details from the video is written as a part of this post.

/>
First I had to upgrade the firmware, since this was about half a year since it was first done, Max had put out 6 new releases in the meantime, which also included support for the 7" Intelligence version of the Nextion display. So no more custom editing and changes to the display, I can just down the image from Max to it!

The first tests after upgrading the Syntherrupter firmware from <a href="https://github.com/MMMZZZZ/Syntherrupter/tree/v4.1.0">v4.1.0</a> to <a href="https://github.com/MMMZZZZ/Syntherrupter/tree/v4.2.0-beta.3">v4.2.0-beta.3</a>, was to test the simple mode with coil settings with oscilloscope. It was confirmed to be 100% accurate with an example of 280 Hz at 60 uS on-time.



For the PC MIDI Setup, I ran through the suggested programs in the Syntherrupter documentation: <a href="https://github.com/MMMZZZZ/Syntherrupter#pc-midi-setup">https://github.com/MMMZZZZ/Syntherrupter#pc-midi-setup</a>. The free SynthFont 1 program gave me a lot of problems with virtual COM port locking up after each played MIDI, so I had to close the program and open it again. I then tried <a href="https://projectgus.github.io/hairless-midiserial/">Hairless MIDI&lt;->Serial</a> and <a href="https://www.tobias-erichsen.de/software/loopmidi.html">loopMIDI</a> together with my regular <a href="https://www.midieditor.org/">MidiEditor</a> program. That worked flawlessly.

To get into the coil settings, its good to remember that buttons with additional settings behind, are highlighted with a double frame in the Syntherrupter UI. You access these deep menus with a long press, as defined in ms in the overall settings menu.

The cutout for the display was not great, I have unfortunately misaligned something, so its shifted 2 mm both left and down. But overall you do not really notice it and the layout of the panel is satisfactory.


16
The phasing of the GDT to IGBT gates are not marked with a dot, are you sure you are driving your half-bridge legs opposite of each other? If you follow that drawing, you are turning on both IGBTs at the same time.

17
Sell / Buy / Trade / Re: How to get rid of stuff?
« on: August 23, 2021, 10:00:42 AM »
I have saved some smaller CRTs for the same project, small retro clocks :)

Looking at how vintage computers are rising in prices, I could only imagine that other electronic things in good condition with through-hole components will follow the same trend. Something that can be repaired and maintained.

I raised the warning limit from 120 days to 365 days, I think its just some default forum etiquette to warn users on bumping old threads. I agree with you, that keeping the information in a single same thread is better than multiply threads with years apart.

18
I got mine up and running with speakers on the 6 outputs, yesterday evening and its a pretty big mouthful to get it all right and to some kind of baseline/default where it acts like I thought it would.

First thing was I could not find the midi channel settings per coil, since I was looking in the wrong part of the documentation :) Maybe a settings button underneath each coil activate button instead? I would also wish for a "midi signal" status blinker on the live midi mode page, just for trouble shooting between pc, syntherrupter and output modules. It would also give some more life to the very static page, when playing MIDI, you got no idea if its playing or not :)

I guess I can just contribute to the documentation on github? I think the PC MIDI setup chapter that you put out in the "front" readme, needs some more integration into the main documentation.

All channels activated for all coils as default, also had me confused, because that sounds very weird and wrong the first time you just try to play a midi. Maybe add new defaults that is just channel 1 to coil 1, 2 to 2 etc.?

Thanks for the explanation on envelopes and demonstration, it really shows how powerful a feature it is.

Did I miss the "omni-mode" somewhere? I thought it could auto-assign midi channels according to active coils and also just randomly choose them? I might remember completely wrong.

As you can see, most of my comments are cosmetics on the UI and documentation, you are doing a great job!

I will admit that the learning curve seems steep, especially with SysEx, envelopes and such, but I hope it will soon make more sense and the prepared midi files on PC for a certain coil setup can just be played and all settings for the coils, channel assignment and such is in the files.

19
Wow, I am completely blown away by the project trail of this thread :) What seemingly was "hey there is this satellite..." and "i got these amplifiers" took us on a extremely long journey of RF hacking!

Regarding the differences in the LDMOS transistors, could it be that its higher quality, special quality, custom matched parts delivered for Nokia Siemens, compared to the "random" public spare parts you can find and buy?

I am looking forward to see you get contact :)

20
Electronic Circuits / Teardown of Servomex CO2 Analyzer 1400 Series
« on: August 17, 2021, 06:43:31 PM »
Old discarded equipment from a agriculture laboratory. Unfortunately damaged from the rough handling. This analyzer measures the CO2 levels in emissions using the principle of infrared absorption.

/>
The front and back of the unit shows that it from the user side is a fairly simply piece of equipment, while a lot more more is going on, on the inside. It is made by Servomex in England, Crowborough, Sussex. On the back there is mains input for 240VAC, a SK5 and PL5 connector for adjacent equipment and a gas in and outlet pipe. The front is fairly simple with a display, alarm LED and buttons. Adjustment of alarm or range is done by 4 potentiometers behind a small lid.



PCB of the display and controls shows a well layout design with high quality components.



The CPU of the unit is a Motorola MC6802p IC which runs at 1MHz with 128 bytes of RAM. The 4 MHz crystal next to the IC is used for the 6802 on-chip oscillator to produce the two-phase 1 MHz clock. The programs are located in the two custom Servomex ROMs dated back to 1990. The PCB features a lot of different components and ICs, that are perhaps chosen like that to hinder others from making a copy of the product. It is rare to see a CPU boards with so many different color components on.



The power supply seems to be four separate units. All controlled by a CA3524E/CA3130E/CA3140E switch mode power supply controller ICs. There is a high current supply for the analyzer chamber and another high power transformer for the infrared system. The rest is house keeping power supplies for the CPU and display.



With the lid off the unit, the first thing that comes in view is the analyzer chamber. With inputs on the right and a single signal output in a black cable on the left.
The detector and chamber construction is of very high quality. It incorporates two kind of detectors, possible one for reference and one that analyzes the gas through the flow chamber with the two pipe ports. The high current supply is for the infrared source. A port for air connection is blinded off. There is also a electromagnet to keep the rotating mirror in a brake position.



The PLT522  is a pyroelectric detector made of lithium tantalate. It has a compensation and amplifier circuit built into its round housing. The infrared filter coating on the rotating mirrors/filters is visible to be multiply layers seen through a microscope.






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[Dual Resonant Solid State Tesla coils (DRSSTC)]
costas_p
September 24, 2021, 07:14:53 PM
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[Dual Resonant Solid State Tesla coils (DRSSTC)]
Uspring
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September 24, 2021, 05:20:01 PM
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Duane B
September 24, 2021, 01:54:49 AM
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[Dual Resonant Solid State Tesla coils (DRSSTC)]
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September 23, 2021, 09:08:23 PM
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[Dual Resonant Solid State Tesla coils (DRSSTC)]
Uspring
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[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
September 23, 2021, 05:46:38 PM
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[Solid State Tesla Coils (SSTC)]
AFreshLad
September 23, 2021, 11:12:25 AM
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[Dual Resonant Solid State Tesla coils (DRSSTC)]
Netzpfuscher
September 23, 2021, 08:49:51 AM
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[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
September 23, 2021, 06:15:34 AM
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[Solid State Tesla Coils (SSTC)]
davekni
September 23, 2021, 05:48:40 AM
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[Dual Resonant Solid State Tesla coils (DRSSTC)]
Uspring
September 22, 2021, 07:21:12 PM
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[Solid State Tesla Coils (SSTC)]
AFreshLad
September 22, 2021, 10:41:20 AM
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[Solid State Tesla Coils (SSTC)]
davekni
September 22, 2021, 07:07:48 AM
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[Solid State Tesla Coils (SSTC)]
AFreshLad
September 22, 2021, 05:26:40 AM
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MRMILSTAR
September 22, 2021, 05:14:30 AM
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Duane B
September 22, 2021, 05:01:22 AM
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[Voltage Multipliers]
MRMILSTAR
September 21, 2021, 10:33:34 PM
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[Dual Resonant Solid State Tesla coils (DRSSTC)]
Mads Barnkob
September 21, 2021, 07:21:50 PM
post Re: Load resistance and discharge terminal for my 14-stage CW multiplier
[Voltage Multipliers]
klugesmith
September 21, 2021, 05:24:35 PM
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[Dual Resonant Solid State Tesla coils (DRSSTC)]
futurist
September 21, 2021, 04:18:47 PM
post Load resistance and discharge terminal for my 14-stage CW multiplier
[Voltage Multipliers]
MRMILSTAR
September 21, 2021, 06:30:44 AM
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[Solid State Tesla Coils (SSTC)]
davekni
September 21, 2021, 06:04:52 AM
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[Dual Resonant Solid State Tesla coils (DRSSTC)]
fh89
September 21, 2021, 03:56:28 AM
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[Dual Resonant Solid State Tesla coils (DRSSTC)]
johnnyzoo
September 20, 2021, 09:24:10 PM
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[Dual Resonant Solid State Tesla coils (DRSSTC)]
Uspring
September 20, 2021, 05:07:43 PM
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Benbmw
September 20, 2021, 04:12:27 PM
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[Dual Resonant Solid State Tesla coils (DRSSTC)]
Chrisader
September 20, 2021, 10:40:33 AM
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[Solid State Tesla Coils (SSTC)]
AFreshLad
September 20, 2021, 10:39:59 AM
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[Dual Resonant Solid State Tesla coils (DRSSTC)]
futurist
September 20, 2021, 10:38:31 AM
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[General Chat]
klugesmith
September 20, 2021, 07:07:55 AM
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[Solid State Tesla Coils (SSTC)]
AFreshLad
September 20, 2021, 06:03:57 AM
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[Solid State Tesla Coils (SSTC)]
davekni
September 20, 2021, 05:31:57 AM
post Re: Help with SSTC feedback circuits with 4046 IC and Schmitt Triggers
[Solid State Tesla Coils (SSTC)]
AFreshLad
September 20, 2021, 04:59:17 AM
post Re: Help with SSTC feedback circuits with 4046 IC and Schmitt Triggers
[Solid State Tesla Coils (SSTC)]
AFreshLad
September 20, 2021, 04:28:03 AM
post Re: Idea for QCW DRSSTC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
September 20, 2021, 12:53:39 AM
post Re: Idea for QCW DRSSTC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
johnnyzoo
September 19, 2021, 11:09:37 PM
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[Dual Resonant Solid State Tesla coils (DRSSTC)]
AstRii
September 19, 2021, 09:47:14 PM
post Re: Idea for QCW DRSSTC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
September 19, 2021, 08:28:05 PM
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[Solid State Tesla Coils (SSTC)]
davekni
September 19, 2021, 08:19:01 PM
post Idea for QCW DRSSTC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
AstRii
September 19, 2021, 07:58:09 PM
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[Solid State Tesla Coils (SSTC)]
AFreshLad
September 19, 2021, 03:16:40 PM
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AstRii
September 19, 2021, 01:32:47 PM
post Re: Help with SSTC feedback circuits with 4046 IC and Schmitt Triggers
[Solid State Tesla Coils (SSTC)]
AFreshLad
September 19, 2021, 10:15:24 AM
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[Solid State Tesla Coils (SSTC)]
Magneticitist
September 19, 2021, 06:32:18 AM
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[Solid State Tesla Coils (SSTC)]
davekni
September 19, 2021, 06:06:44 AM
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[Solid State Tesla Coils (SSTC)]
AFreshLad
September 19, 2021, 04:14:18 AM
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[Solid State Tesla Coils (SSTC)]
Magneticitist
September 18, 2021, 11:33:37 PM

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