Fluxer Heaters, induction heaters for Dynavap

[Moses Baca]

Mother Fluxer requests? Simple is best.

Multiple coils is overkill. Just more stuff to break. One coil with adjustable heat/PWM that's easy to adjust. Slow roast to nuclear fast at the twist of a dial.

Plug-in for home use or stick some batteries in for portable. Built-in battery charger is not needed. It just adds more holes to the enclosure.

Easy, right? Thanks for asking.

MB

 

[Dank_Star]

I'm with @Moses Baca, single coil (with options for diameter) and adjustable PMW temp control...Glad to see your focus coming back to the MF Mr_C , it is indeed a Happy Easter

 

[ClearBlueLou]

I don’t want the sun to go down on a dual coil
...having dual coils of ONE size would make the MF the life of any vapcap party

Being able to pick the size would be extra bonus, but streamlining the production will be helped by fewer variations. DELIGHTED the Mother has been bumped up!


(Yeah, I originally suggested two different diameter coils, but thinking about it, the chance for confusing those unfamiliar seems too high...better to have a single size, and pack a deluxe for an alternate size... (IMO)....)

 

[BouncingOffClouds]

I have returned! Using my fluxer tonight like a pro tonight after plenty of practice and a few mistakes. Combined with the 2019 M that arrived today, I'm feeling pretty satisfied and grateful! The wait was absolutely worth it.

 

[Lovecraft]

Finally my comfirmation mail arrived!! had replied with all the options choosen ,but still waiting for the mail with the payment info. so happy 'to see the moment my fluxer arrives is closer!

 

[mr_cfromcali]

Hi everyone,

Sorry for not posting sooner this week.

Flux Deluxe: Unfortunately, I learned this week that several recent Flux Deluxes failed soon after their new owners received them. ...

It isn't the MOSFETs this time, but, ironically, the diodes I added to protect the MOSFETs. Some of these have failed, and when they fail, they often fail to a shorted condition, which trips the power fuses. When this happens, your FD goes immediately from On to Off. There is a very, very quick blip from the green LED, then radio silence. When the diodes fail in this way, the only fix is to send it in for repair.

I don't yet know the exact reason why some of these diodes are failing yet, but being subject to too much power is the most common cause of zener diode failure, so it seems like that may be the case here, too. Prior to adding these diodes to the FD's circuit, I calculated that the maximum potential power they might need to dissipate would be 335 mW, or about 1/3 of a watt. I chose to use 1W diodes for the added overhead they provided.

It's possible that my math and/or my measurements were off, and the actual power these diodes need to dissipate is higher than my estimate. With that in mind, I have ordered some 2W versions of the diodes in this solution, and will be using those going forward. The circuit may still fail for other reasons, but these should be overkill for any power surge this circuit is capable of producing.

I expect to have the correct parts on hand by mid-week. The 2W "through hole" diodes I use to repair existing PCBs are the same size as the 1W versions, so those will be easy to use going forward. I had already revised my PCB to incorporate the 1W diodes, and I need to revise that again to use these new, physically larger 2W diodes, so it will be at least another week or so before I have the new PCBs at hand.

TL;DR: Some recently built and repaired Flux Deluxes may still be at risk for component failure due to a potentially undersized part. If this part fails, your heater will trip its fuses and shut itself off - there's no danger, but there won't be any heat, either. If you find yourself in this situation, you will need to send your heater back for repair, as it isn't something you can fix yourself. Please send me an email and we will go from there. Thank you, and I am very sorry for any additional hassle this causes anyone.

Thanks, everyone. I'll share more info about this (or other potential issues) as I learn of it.

Cheers,

 

[ClearBlueLou]

Sorry to hear about the extra snag! I can only hope testing thru components is less frustrating and quicker than trying to debug code...as the end-result of all this will be a more bulletproof unit, I can only hope the extra work is rewarding.

I appreciate your diligence and cheer on your efforts

 

[mr_cfromcali]

Thanks, @ClearBlueLou . It's similar to debugging code in many ways, but it takes longer because new stuff needs to physically come to me before I can test it in the circuit.

=-=-=-=-=-=-=-=

First things first: If you have a heater that fails, please contact me, and we will discuss next steps.

Second thing: I'm not shipping any new heaters until I resolve this issue. I believe that will only be a few days. More info below.

=-=-=-=-=-=-=-=-=

More info on the &#^$ diode issue:

I've been working on this issue quite a bit today.

It does look like my math was off wrt the load these diodes need to withstand, and as a result I used an under-sized diode for this. This stuff happens, of course, but I am very sorry it happened here.

Despite this setback, I still have a lot of confidence that this voltage protection circuit is the correct one for this heater, and with a higher wattage part will it function as expected. I think this device will be stable once these diodes are sized correctly for the load.

I have asked some people with more knowledge than me for help, and I hope to have the correct answer to this within a day or two.

I'm sorry we're still talking about issues rather than new features, but I try to be transparent with these things when possible. No one likes bad news, but I find honesty is a lot better than deflection and spin. This device is still evolving. It has come a long way in a short amount of time, but apparently it isn't quite done. I am not giving up on it, but I will certainly understand if some of you have, or decide to.

I hope you stick around, though, as I am continuing to work on features and improvement for future releases - stuff that will be more enjoyable to share once these things are working more reliably as heaters.

Finally, more info on the ways this failure presents itself:

These will diodes most commonly fail closed, as I described in my previous post, above. In this circuit, that means they will connect to ground and trip the fuses, stopping the heater, etc.

It is also possible for the diodes to fail open, however, and essentially delete themselves from the circuit. If they fail this way, the heater will continue to work for a time, but the MOSFETs will be unprotected, and they will probably fail sooner or later due to the loss of their voltage spike protection.



Thanks again for your support and patience!

I'll post more when I have some more news to share.

 

[pxl_jockey]

When rolling out a new product, especially electronics, there will be hiccups and unforeseen problems. Talk to anyone with experience and it’s inevitable that issues will arise. For me, it’s how the company/person deals with the challenges and that includes the communication with the client/customer.

Shit can be expected to happen in the real world and in the case of the FD, it has taken some time out in the real world for it to hit the fan. I know that I spent a lot of time trying to break my unit and find a way to cause a failure before it was rolled out to waiting customers and I wasn’t alone.

Way before that, I was impressed by mr_c’s transparency and integrity, not to mention the willingness to change up his development process & product features based on community feedback. Nothings changed. He’s still got the curtains pulled back and standing behind his vision. It’s still very early days for the fluxers; I just see no reason to start doubting these projects now and have plenty of faith that we’re all still going to wind up with the most robust and innovative vapcap IHs out there. But that’s just me.

 

[Obsessed 2]

I just see no reason to start doubting these projects now and have plenty of faith that we’re all still going to wind up with the most robust and innovative vapcap IHs out there. But that’s just me.

Exactly. Because of how MrC has presented his processes with transparency and integrity, I am staying onboard for the end result. I have to be honest and confess that I have doubted my decision to stick it out, repeatedly. The pitfalls and obstacles could understandably drive one away but it is completely how it has been handled that puts my faith in his vision, restored my patience, and fired up my excitement that my time is coming. Now if only everyone with a functioning FD could please keep quiet until I get one, yeaaaah,... that woud be great.

 

[lookhigh]

What @pxl_jockey and @Obsessed 2 said, much better than i could.
Also excited about these new features???

 

[mr_cfromcali]

Thanks again for your support, @pxl_jockey , @Obsessed 2 , @lookhigh , and everyone else who has been following the project and is interested in seeing where this thing goes. Your support makes it a lot easier to absorb the frustrations that come with this sort of endeavor.

Update on the *&^*# diode issue: I asked some questions of people who know more than I do, and was pointed to a class of specialty diodes with which I was previously unfamiliar, called transient voltage suppression diodes.

From the above link: "While the VI [voltage to current] characteristic curve of the TVS diode is similar to that of a zener diode, TVS diodes are specifically designed, characterized, and tested for transient voltage suppression. By contrast, zener diodes are designed and specified for voltage regulation."

TVS diodes are purpose built for absorbing voltage spikes, and can take quite a hit. They are much better suited for this sort of task than the zener diodes I had used previously. TIL.


I've ordered some and am expecting them to arrive tomorrow. These look SUPER promising on paper, and are direct replacements for the zener diodes. I will report back with more data once I have it. Stay tuned.



Cheers,

 

[vapognak]

That sounds great! Thank you so much for the detailed explanation, it's very reassuring to have fully access to your research and building process.

 

[mr_cfromcali]

Hi all,

Some good news - the TVS diodes got here, and they seem to work! And well! Will need to see how they hold up, of course, but they work exactly as they are supposed to in their primary role as voltage suppressors. Have a look.

Test bed for these measurements is a Flux Deluxe with a 15mm coil and 3 freshly charged Sony VTC-5D (heavy discharge rate) batteries. This is the most powerful set of 18650 batteries I have. (As an aside, your FD doesn't need heavy discharge rate batteries - a set of Samsung 35E is cheaper and will last longer than the VTC-5D in this application. But I digress...)

This is the "before," captured immediately prior to TVS diode installation, with no voltage suppression diodes present. The purple line is the voltage measurement at the MOSFET's source pin, while the yellow is the voltage as measured upstream of the MOSFET, near the capacitor tank. The oscilloscope's trigger was set to capture any event on the MOSFET source pin >33V.

The only instance where we see voltage this high in the circuit is when the tactile switch is released and the magnetic field in the work coil collapses. Once released, all of the energy that was in the magnetic field and coil must dissipate, and it will take the easiest path to do that.

That's 102V (!) pushing itself back into the heater circuit following the release of the tactile switch - to fit on the screen, the scale of the yellow line is 2x that of the purple one. Voltage is still 46V by the time it reaches the MOSFET's Source pin, which has a rated max spec of 40V. That's a pounding, and it won't stand up to that sort of abuse forever.


This is after TVS diode installation:

Yes, you are reading that correctly - the TVS diodes absorbed the 80V spike without a hiccup and safely shunted it to ground, bringing the voltage down to a safe and expected range for this device. This is DEFINITELY good news!! The sharp-eyed may even note that I had to drop the scope's trigger level below 28V to capture this event.

Now, the zener diodes I was using previously performed a similar task in a similar way, but they fell down when asked to absorb the energy being directed at them by the heater. And that is the main difference between the two types of diodes - the TVS diodes are designed to take a beating. Each of the TVS diodes I'm using is rated to absorb a maximum of >13A in a single event! I'm using two of these diodes, giving the circuit over 27A of current absorption. That ought to be sufficient.

Anyway, I am very, very happy these are working! I'll do as much additional testing as I can from here to see if I can make them fail. I'm not expecting them to fail, though, as they are installed properly and are designed to do exactly the task they are doing.

So...I am going to end this post with a very cautious YAY!, and will come back later with some more results and user experiences.

TL;DR: The TVS diodes work, and well! So far, so good!

 

[started@52]

Excellent news!

 

[ClearBlueLou]

Great to hear! Problem-solving has its own pleasures - but nothing like the pleasure of problems SOLVED!!

 

[mr_cfromcali]

Excellent news!

Great to hear! Problem-solving has its own pleasures - but nothing like the pleasure of problems SOLVED!!

Thanks guys. Unfortunately, I'm seeing failures now after the initial success I posted above.
There's more work to do on this, unfortunately...

 

[ClearBlueLou]

I know you’ll get it knocked...cheers!

 

[mr_cfromcali]

OK, I did some thinking, and I have a theory about why things worked as well as they did at first but have since stopped: It worked when the battery pack was depleted, and failed when those batteries had had time to rebuild their charge.

To make a long story short, I still think I have the right kind of diodes, but the voltage range I chose initially is too low, as the TVS is getting activated too soon, likely during the initial power surge when the On/Off switch is first turned on. There is a particular "TVS activation voltage" spec (aka its Reverse Standoff Voltage, for the technically-minded), and this is in range of the power surge from a fresh battery pack. It doesn't need to be. I have room to move the activation point to a higher voltage, so I am going to give that a try and see what happens.

I believe my first heating cycles today were below the present TVS diode's activation point, and my bad cycles were above this voltage. The bad runs activated the TVS for a much longer period of time than planned - seconds vs. microseconds, and it died about a full second into the cycle. The actual events I want to protect against are microsecond-length events, so I need to re-size the diode to one with a higher activation voltage, so I am only using it when necessary.

I have some more TVS diodes coming tomorrow, in slightly higher voltage ranges and a variety of power ratings, and we'll see if these work any better. Onward!



Who needs reality TV, right?



(edited for...clarity?)

 

[mr_cfromcali]

Hi all,

Back with more exciting Flux Deluxe TVS Diode Updates.

Today's Special: 24V TVS Diode Oscilloscope Graphs!

Good news, folks - the higher voltage TVS diodes look like winners so far! To save time I didn't circle stuff in the graphs below as I did yesterday before, so I'll narrate.

BTW, today's observations are brought to you by yesterday's blown parts. It's easier to find stuff if you know what you're looking for.

As with yesterday's graphs, the yellow line shows the "system" voltage as measured at the capacitor tank. It can run much higher than 40V. As I showed yesterday, when left unprotected it can go as high as 100V or more! The heater uses capacitors rated to 630V, so high voltage here isn't a problem, per se.

The purple line is showing the voltage on one heater MOSFET Source pin, and this is where high voltage becomes a problem. The pin has a max of 40V, as previously discussed.

This is the initial power surge from turning on the On/Off switch, which I did not consider until the heater forced me to.

Look at the line in yellow, which has a max of 20.8V:

The TVS diodes I opened with yesterday became active in the circuit at 18V or so - too low and restrictive a value for real world conditions.

The diodes I am using in the graphs below have an activation voltage of 24V, which I believe is around the sweet spot. I want to keep them inactive and out of the circuit until they are truly necessary, which is when the magnetic field collapses following the release of the tactile switch. I have a few others TVS values coming today and tomorrow, so the final choice may be a few volts higher than the one used in the results below. These are working quite well, however, so they may yet get the gig.

These final two graphs show the same 15mm FD as yesterday with just a single of these 24V TVS diode installed in the heater:

The purple MOSFET Source pin voltage is a very ho-hum 27.2V (in purple), which is great! That's WELL within spec.

Finally, the graph below shows a heating event in which the Flux Deluxe was charging a set of Sony VTC-5D batteries while also plugged into a 10A mains power supply - not recommended and not supported at this time. But it handled the situation just fine:

I am going to continue to test this solution in a variety of situations to see if I can break it, but I am very encouraged so far.

And that's your midday Fluxer TVS Diode Report. I'll probably be back again later with another update.




Cheers,

 

[lookhigh]

roller coaster

 

[ClearBlueLou]

Onward and upward, Edward!

 

[mr_cfromcali]

Hi all,

I promised I'd post an update after some more testing, so I just want to share that the higher voltage TVS diodes continue to function as expected, both on the scope and IRL. I haven't been able to break either the diodes or the heater yet, and not for lack of trying. I have been schooled by this issue for a while now, but this is looking very promising. So far, so good.

I have a few more diodes to audition tomorrow, in neighboring values. I'll see how they perform. The optimum diode will be the one that remains inactive during normal operation while providing maximum surge protection when needed. It may turn out to be the one I'm currently using, but the new parts should provide enough choice to make a solid decision.

I'll post more after some more testing and evaluation. Thanks for following along

Cheers,

 

[pakalolo2]

Hi all,

Back with more exciting Flux Deluxe TVS Diode Updates.

Today's Special: 24V TVS Diode Oscilloscope Graphs!

Good news, folks - the higher voltage TVS diodes look like winners so far! To save time I didn't circle stuff in the graphs below as I did yesterday before, so I'll narrate.

BTW, today's observations are brought to you by yesterday's blown parts. It's easier to find stuff if you know what you're looking for.

As with yesterday's graphs, the yellow line shows the "system" voltage as measured at the capacitor tank. It can run much higher than 40V. As I showed yesterday, when left unprotected it can go as high as 100V or more! The heater uses capacitors rated to 630V, so high voltage here isn't a problem, per se.

The purple line is showing the voltage on one heater MOSFET Source pin, and this is where high voltage becomes a problem. The pin has a max of 40V, as previously discussed.

This is the initial power surge from turning on the On/Off switch, which I did not consider until the heater forced me to.

Look at the line in yellow, which has a max of 20.8V:

The TVS diodes I opened with yesterday became active in the circuit at 18V or so - too low and restrictive a value for real world conditions.

The diodes I am using in the graphs below have an activation voltage of 24V, which I believe is around the sweet spot. I want to keep them inactive and out of the circuit until they are truly necessary, which is when the magnetic field collapses following the release of the tactile switch. I have a few others TVS values coming today and tomorrow, so the final choice may be a few volts higher than the one used in the results below. These are working quite well, however, so they may yet get the gig.

These final two graphs show the same 15mm FD as yesterday with just a single of these 24V TVS diode installed in the heater:

The purple MOSFET Source pin voltage is a very ho-hum 27.2V (in purple), which is great! That's WELL within spec.

Finally, the graph below shows a heating event in which the Flux Deluxe was charging a set of Sony VTC-5D batteries while also plugged into a 10A mains power supply - not recommended and not supported at this time. But it handled the situation just fine:

I am going to continue to test this solution in a variety of situations to see if I can break it, but I am very encouraged so far.

And that's your midday Fluxer TVS Diode Report. I'll probably be back again later with another update.




Cheers,

No worries here, still looking forward to your getting to where it’s needs to be. Innovation takes time and patience. That said, I’ve got a brand new addition to the family from Simrell Collections ready for my new Flux Deluxe.

 

[Terpenetime]

I ordered a Flux Deluxe on the 28th March and I fear that I’m no closer to getting it now than I was then!

Do I care?

No, I do not!

Just reading about the highs and lows of getting this project off the ground makes me fully appreciate how hard mrc_fromcali is working and how great will be his achievement when he finally gets it there. I haven’t got the slightest understanding of most of the information he provides but the mere fact that it’s there at all is enjoyable in itself.

I’m with you all the way mrc_fromcali