Tetra Replication

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sergh

Re: Tetra Replication « Reply #25 on: 2024-04-18, 12:26:41 »

Jr. Member

Posts: 81

Quote

AWG 32 wire for coil, max current 0.09A, not much.

If you have short pulses with a high duty cycle, then 100 or 1000 amperes can pass through such a wire without heating it at all, because the average power of such pulses is negligibly small.

When working with short pulses with a high duty cycle, it may be difficult to correctly measure their parameters.
Not everything is so simple; conventional measurement methods can lead to significant errors.

Grumpy

Re: Tetra Replication « Reply #26 on: 2024-04-18, 15:10:48 »

Group: Tinkerer
Hero Member

Posts: 3948
tExB=qr

Spherics stated: The frequency should be a harmonic of the NMR of iron.
(Note that this is without other fields to interact with.)

Later, Spherics states:
Deliberately this tetrahedral TPU requires high megahertz square pulses. The SEP coil is pulsed to ensure a release of the ether pattern to prevent build up at low repetition rates. Only at high megahertz does the pattern caused by release combine with the next pulse to effect the COMP field. This deliberately puts experimenting into the hands of people who have some electronics familiarity.

If you were to include another always on SEP coil in the same orientation as the combined SEP coil but large enough so the whole spheric TPU could fit inside you would have a working model at 300V repetition pulse rates as lows as 3khz especially if the SEP coil is powered by high voltage and high amps. The temptation to route DC output back into the SEP coil to see-what-happens is almost a given. What happens is a run away event in microseconds that turns you and your experiment into shrapnel.

chief kolbacict

Re: Tetra Replication « Reply #27 on: 2024-04-18, 16:35:32 »

Sr. Member

Posts: 302

Take a vacuum lamp, and have a lucky.
For example GU50.

Why not ?

bte

Re: Tetra Replication « Reply #28 on: 2024-04-20, 13:55:02 »

Group: Moderator
Sr. Member

Posts: 308

Applying final touches to the schematic, then I'll route and order the PCB and components...

bte	Re: Tetra Replication « Reply #29 on: 2024-04-26, 14:42:17 »
Group: Moderator Sr. Member Posts: 308	Simplifying the schematic to get this out the door. PCB problems complicating efforts. I've changed to DS1023's for pulse width control, which will make it easy. I'm going to hard switch those RF mosfets that sergh posted.

bte	Re: Tetra Replication « Reply #30 on: 2024-04-27, 19:52:11 »
Group: Moderator Sr. Member Posts: 308	Awaiting PCB review. ------------------------ Tetra Replication circuit.png (52.36 kB, 787x663 - viewed 374 times.)

bte	Re: Tetra Replication « Reply #31 on: 2025-02-12, 23:07:53 »
Group: Moderator Sr. Member Posts: 308	Was going to post pictures but I get an error that says the upload folder is full.

bte	Re: Tetra Replication « Reply #32 on: 2025-02-12, 23:10:10 »
Group: Moderator Sr. Member Posts: 308	Another try. Here are the images: https://imgur.com/a/Y0mxHlQ

bte	Re: Tetra Replication « Reply #33 on: 2025-02-12, 23:15:54 »
Group: Moderator Sr. Member Posts: 308	Correct angle for the tetra is 19.5 degrees, not 30 degrees as Spherics stated. It was an error on his part. 30 degrees is the angle when projected from a side of the tetrahedral.

bte	Re: Tetra Replication « Reply #34 on: 2025-02-12, 23:42:16 »
Group: Moderator Sr. Member Posts: 308	300v supply. Simulating max power of 60ma. Falstad circuit: https://www.falstad.com/circuit/circuitjs.html?ctz=CQAgjCBMB0CsAMinOQFgKYFoDs5bVW0mwDZsBObMMADhLHnJAGZdYQEOtqAoANyg0aUWCUHCwpEPGkgSMsJFkz4cHgBsQqMGMljUJVOCkroaXKvrl4CZjtiQGqVtJ5hYTA0b1bDIsUqq8EoMKMhQagAmvt5SDhJSSpHoAGYAhgCu6gAuPADGHJAJYvFQqDJGQcjkNbV19UzMiGbw2MxFNETkkDXSLRDwPABOhcWjIORiMjXIw+OT4zqyoYg8AOaLJUXKrpCt8yVSC+x8APYZuQDuLHv+4neDI7BSPs8B5bIIq9ded6WQolc13+gP+H0GwO2AMOAUBEI4iVBiXB6xuMmhaPuKh4aS0NBksEUHG6HCJwnYCjCfUmAMQBhoYFYjKkzGgDLoe0gqEmThs3hQPAASniKgtUPitO1ZMwWOEYNh2PKKX1YDw9rhUOKoPBhOV0TqOCAAA6XAC2+RixhKRMgXK04CwTCCzGY5XkhkcknxNEC-SBpKUtqMvwxg1xQfGTSMpV10As4CpMDqJD2zB9ti5uCTtVIRE18T2ugFBQjIaIlqMNGgkCaYRQYCwuEwqionRIPrbNfg8mEVQGc2ISl+UctlJWFtLSxH2n0cgIWGEzbZtBIsB91GY8h1+z7-tLfgjhMCPGu+6Mk6mJ9lwan8GDfnh078I9Kg2F1CUsE1eI435UWhkGV-1UVVgReOJth8QZ1XAeQA3AbYj0NM4LivHQCRtO0kMfO9I3bcZH3w0pxQJbZ4WcQNARDOE5naBQWXwqCVSvTcxhnK1-Qou46IeNV9g8T8iUMDDP2NM0LVYjieIxSoWltcAwGgagGHIZxWhIQx8SAv1HgUz9v3Q39KgTVYCkMr9vDggT7SqJAGns2oIjqXMuVQAtuz6RB+w2cySUMlNjPhczv0PP8rw6KTbignhTmWMjtXFAYWngCBsDZV1sGCEhVIoF0aGMwIWBihN4IqRhhB41QIAgEJAOK6qpklWAZWEhC2SgDqIGYHggA

bte	Re: Tetra Replication « Reply #35 on: 2025-02-15, 00:03:29 »
Group: Moderator Sr. Member Posts: 308	Looking at this eval board for a GaNFET. This thing can switch ~480V at 3.6Mhz Going to order one to see how it handles pulsing the tetra, then order 3 more and see if the correct frequency is around ~3Mhz. If not, ill order 2 more and round robin the FETs for coil A. That's the plan for now. Once I know what the frequency is, I can design something less dense than these eval boards with simpler electronics. These are heavy duty state of the art FET boards. If these FETs can't reach the target, then I doubt I'll be able to figure this thing out unless spherics shows up magically and offers more advice. https://www.ti.com/product/LMG342X-BB-EVM/part-details/LMG342X-BB-EVM

verpies

Re: Tetra Replication « Reply #36 on: 2025-02-15, 00:57:26 »

Group: Professor
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Posts: 3670

Quote from: chief kolbacict on 2024-04-18, 16:35:32

Take a vacuum lamp, and have a lucky.
For example GU50. Why not ?

Because vacuum tubes operate at high voltages and low currents.
The magnetic fields generated by coils are proportional to the electric current flowing through them ...not the voltage.

Surplus MRI amplifiers are an economic solution for driving coils with high RF currents. They usually use Ampleon's LDMOS transistors or GaN-SiC HEMTs.

bte	Re: Tetra Replication « Reply #37 on: 2025-02-15, 01:13:41 »
Group: Moderator Sr. Member Posts: 308	Quote from: verpies on 2025-02-15, 00:57:26 Because vacuum tubes operate at high voltages and low currents. The magnetic fields generated by coils are proportional to the electric current flowing through them ...not the voltage. Surplus MRI amplifiers are an economic solution for driving coils with high RF currents. They usually use Ampleon's LDMOS transistors or GaN-SiC HEMTs. Not familiar with these, can you give an example of one? Sounds promising. Building SMD boards is my weakness.

verpies	Re: Tetra Replication « Reply #38 on: 2025-02-15, 01:23:19 »
Group: Professor Hero Member Posts: 3670	Quote from: bte on 2025-02-15, 01:13:41 Not familiar with these, can you give an example of one? Sounds promising. Building SMD boards is my weakness. For the examples, click on the blue link in my message. For amateur use, the boardless "dead bug" construction with minimum lead lengths offers better performance than a PCB construction because air has better dielectric properties than any PCB material. A heavy heatsink is still required. If you have more money than time on your hands, then below is a ready-to-use wideband RF amplifier: https://www.ebay.com/itm/155677365741

bte	Re: Tetra Replication « Reply #39 on: 2025-02-15, 02:32:24 »
Group: Moderator Sr. Member Posts: 308	Now im down a rabbit hole of looking at various ways to make a pulse other than just switching a mosfet... So the problem is that most solutions can't do 300V or can't go to 10Mhz. One idea I had was to round robin mosfets to get to 10Mhz, but that's alot of timing logic and one transistor being bad can wreck it. Another idea is to go RF route, maybe try to generate a 3 phase sine, then make a circuit to somehow shape it into a pulse when it peaks.

bte	Re: Tetra Replication « Reply #40 on: 2025-02-15, 03:08:57 »
Group: Moderator Sr. Member Posts: 308	I might be overthinking. What if I just operate in linear region and not hard switch the coils? The bias might be helpful even. Need to learn how to work with rf Amp circuit.

verpies	Re: Tetra Replication « Reply #41 on: 2025-02-15, 10:59:57 »
Group: Professor Hero Member Posts: 3670	Quote from: bte on 2025-02-15, 02:32:24 Now im down a rabbit hole of looking at various ways to make a pulse other than just switching a mosfet... A simple relaxation oscillator based on an avalanching HV BJT is capable of generating nanosecond pulses with picosecond rise and fall times and kHz PRF. ...and the waveform generated by this pulser into a 50Ω load with 100VDC applied to the 1.2MΩ resistor:

bte	Re: Tetra Replication « Reply #42 on: 2025-02-15, 12:51:43 »
Group: Moderator Sr. Member Posts: 308	Quote from: verpies on 2025-02-15, 10:59:57 A simple relaxation oscillator based on an avalanching HV BJT is capable of generating nanosecond pulses with picosecond rise and fall times and kHz PRF. ...and the waveform generated by this pulser into a 50Ω load with 100VDC applied to the 1.2MΩ resistor: Looks interesting, do you have a diagram?

verpies	Re: Tetra Replication « Reply #43 on: 2025-02-15, 16:00:53 »
Group: Professor Hero Member Posts: 3670	Quote from: bte on 2025-02-15, 12:51:43 Looks interesting, do you have a diagram? Yes, it is somewhere on this forum (search for the keyword "picopulser"), but this circuit is so simple that you can surmise it from the photos. The two 20kΩ resistors are connected in parallel and used to ground the base of the BJT. The two 100Ω resistors are connected in parallel, too, ...and across the BNC connector terminals. The two 1.5pF capacitors are connected in parallel, too, between the collector and ground. The 1.2MΩ resistor is connected to the collector, too. The output pulse is taken from the emitter.

bte	Re: Tetra Replication « Reply #44 on: 2025-02-15, 17:01:16 »
Group: Moderator Sr. Member Posts: 308	It's very cool, I'll search for it. Thanks! I think I'm going to go for 1mhz top speed driver circuit. I'll just use my outer SEP to lower the repetition rate.

verpies	Re: Tetra Replication « Reply #45 on: 2025-02-15, 18:54:22 »
Group: Professor Hero Member Posts: 3670	Quote from: bte on 2025-02-15, 17:01:16 I think I'm going to go for 1Mhz top speed driver circuit. I'll just use my outer SEP to lower the repetition rate. I don't understand what you mean. The maximum frequency component of a 1% duty cycle 1MHz rectangular waveform can easily exceed 999MHz. What pulsewidth and PRF are you aiming for ? What about the maximum acceptable rise/fall times of the pulses?

bte	Re: Tetra Replication « Reply #46 on: 2025-02-15, 19:30:58 »
Group: Moderator Sr. Member Posts: 308	Pulse width 25ns, 1mhz repetition rate, 300v rail. I'd like to try for 10mhz with ganfets.

bte	Re: Tetra Replication « Reply #47 on: 2025-02-15, 19:32:47 »
Group: Moderator Sr. Member Posts: 308	Quote from: Grumpy on 2024-04-18, 15:10:48 Spherics stated: The frequency should be a harmonic of the NMR of iron. (Note that this is without other fields to interact with.) Later, Spherics states: Deliberately this tetrahedral TPU requires high megahertz square pulses. The SEP coil is pulsed to ensure a release of the ether pattern to prevent build up at low repetition rates. Only at high megahertz does the pattern caused by release combine with the next pulse to effect the COMP field. This deliberately puts experimenting into the hands of people who have some electronics familiarity. If you were to include another always on SEP coil in the same orientation as the combined SEP coil but large enough so the whole spheric TPU could fit inside you would have a working model at 300V repetition pulse rates as lows as 3khz especially if the SEP coil is powered by high voltage and high amps. The temptation to route DC output back into the SEP coil to see-what-happens is almost a given. What happens is a run away event in microseconds that turns you and your experiment into shrapnel. Because I'd like to experiment with no sep eventually per this post.

verpies	Re: Tetra Replication « Reply #48 on: 2025-02-16, 01:11:59 »
Group: Professor Hero Member Posts: 3670	Quote from: Grumpy on 2024-04-18, 15:10:48 Spherics stated: The frequency should be a harmonic of the NMR of iron. What do you think the fundamental NMR frequency of pure iron is ? Without and with an externally applied magnetic field... Quote from: bte on 2025-02-15, 19:30:58 Pulse width 25ns, 1mhz repetition rate, 300v rail. That is a 1 MHz waveform with a 2.5% duty cycle. Its maximum frequency component is at least 40MHz ...or more if the rise/fall times of the pulses are short (squarish). What is the resistance and reactance of the load which you plan to apply these pulses to ?

bte	Re: Tetra Replication « Reply #49 on: 2025-02-16, 01:59:03 »
Group: Moderator Sr. Member Posts: 308	Quote from: verpies on 2025-02-16, 01:11:59 What do you think the fundamental NMR frequency of pure iron is ? Without and with an externally applied magnetic field... That is a 1 MHz waveform with a 2.5% duty cycle. Its maximum frequency component is at least 40MHz ...or more if the rise/fall times of the pulses are short (squarish). What is the resistance and reactance of the load which you plan to apply these pulses to ? From my notes it should be 3.237778 MHz Then coil A is driven 3x that, so 9.713334 Mhz for coil A With external magnetic field the original author states that the pulse rate can be lowered to ~3khz, when the field coil is powered "by high volts and high amps" = very strong magnetic field. My coils are all matched to about 175mH, 144 ohms in a brooks coil configuration. You can see the bobbins in the pictures earlier in the thread. Once I can find a frequency range I can simplify more, try different things, but for now I need to actually be able to sweep the frequency range up to ~10Mhz. I've added a round robin pulsing setup for the top coil, 3 mosfets will round robin pulse coil A to reduce the frequency requirements for each individual mosfet. So if I pulse at Iron's NMR, it would be 3.3Mhz per mosfet, which these GaNFETs are rated for (>10Mhz switching capability). My hope is that I can use a strong magnetic field, find some frequency ranges with a response, and slowly turn down the power and see how the frequency response changes, so I can get a better estimate. One of the reasons I want to try to avoid using the magnetic field coil is to research an effect the author stated where "quite frankly, you can stick two 3/4cm copper bars in the field and measure substantial voltage and current", that implies the field is rotating at an extremely high speed. Worst case, I just use my magnetic field coil and be happy if I get a result.