VapCap Induction Heater for Desktop and in Car Use

[Pipes]

Hmm, you term "high-rise" has me a little confused. Works in houses too!
I think your talking about the transition time or rise time for the voltage to be presented. Meaning the voltage must be switched to the "on" state quickly, which is pretty much any switch will do. The voltage must also be high enough get the oscillation started between the push/pull FET oscillator. Should not be a concern for these drivers as long as you stay over a 9 volt setup.

If the board is shorted meaning the FETs are shorted, the supply will kick into protect mode right away and usually pulsates. The led on the driver board may also dimly flicker at the same rate. However, direct wiring should not have blown the FETs. Applying power without the coil securely attached or leaving it run continuously will though. Also, a bigger issue is the driver board component and assembly quality which might be the problem.
Being down that hole enough times.

Hope this helps and good luck.

 

[nachooo]

Hello all, just a dumb question… I am in the making of my second induction unit, this one will have some improvements..battery level indicator, bigger battery capacity, the mosfet and security switch, and a metal or good quality plastic enclosure..I am thinking in a hammond plastic or aluminium case...Well...as the zvs is 5, 5 x 4 cm I want to keep more or less these base dimensions and make it about 12 cm heigh..finally a 5,5x4x12 cm will be true portable...but my problem is that the only lipo batteries that fit in that space and could give me the desire capacity (about 2000 ma and up) have to be two units in parallel… of course I will use exactly the same type of battery for the both units. So... Will be a problem to use two 3s Lipo in parallel?

Also I am thinking on add a liitle moving piece, it should be easy to move..that could cover the hole where the dynavap cap heats to avoid Little things to go inside… Other interesting thing I am considering is to make the design in a way that almost all my dynavap M rest inside the little box..So the inductor coil rest at the bottom...and a hollow tube is over it ..all inside the box ..So you can keep the dynavap inside instead of use other enclosure for it.
Thanks for reading

 

[rz]

@zky42 Welcome! Congrats on the IH build. looking nice and snug in there. Please be super careful to avoid any short circuits as these batteries can pack a serious punch. If that is copper foil, it looks pretty close to some critical areas that may not even be protected by your BMS!. Look into kapton tape or a thin silicone sheet if you're interesting in electrically / thermally shielding the pack from the IH.



@nachoo technically you could parallel 3 sets of individual cells to create a "3S2P" battery pack. It is not just the pack that needs to be paralleled, but each set of cells, and care should be taken to have them connected in a way that can handle any imbalance of current between the cells.

If you are constructing a pack out of pairs of individual cells, you could definitely assemble a 3S2P pack. However RC battery packs are not designed to be connected in this manner. The wires coming out from between the cells are designed for monitoring and (slowly)balancing a pack during the charging cycle. This is evident by the smaller wires used compared to the positive and negative lead, which carries all the current. Even though the current imbalances wouldn't be much between a well-matches batch of cells, and it may work, I'd personally avoid it unless you could verify the pack is designed for this kind of use or modified to be..

Looking for perfect enclosures is a pain in the ... It's really hard finding one that matches your exact requirements. I've spent days staring at enclosures wondering if or how I could stuff things into them. Keep lookin and thinking of ways, and I'm sure you'll come up with something. BTW, you could also look into 4S packs. you would probably need to tune/modify the driver a bit to keep power consumption / delivery in an ideal band.




@samlant the circuit (heavily depending on the selected components) needs around 6V minimum to start oscillating. If this circuit for any reason fails to oscillate, it usually results in a blown MOSFET. A power supply needs to be able to provide the inrush current (initial burst of current to fill the capacitor) without dropping much below around 6V even for an instance, and ideally not fluctuating much at all under load, taking into account all sorts of losses along the way (like resistance of wires). This will depend on it's construction, and a supply that can't handle the load gracefully will likely result in.. a blown MOSFET. The ZVS modules may often have MOSFETs that just aren't suitable for the job, and cause a fuss very easily. Anyone DIYing with these modules should try get some spare MOSFETs or spare modules at least, cause well.. they blow.

Fortunately, with the right components, and a good power supply the circuit seems pretty reliable

What power supply are you trying to use?

A 12v 5A switch is VERY marginal. It may work as an only switch if you've tuned your IH to operate below 60W, though switching high currents will take it's toll on a switch which may eventually die.. High current switching should rather be left to a MOSFET (module), or to the existing IH MOSFETs by tapping directly into their gate resistors and switching the voltage to those. In these cases, a much smaller momentary switch can be used (ie, under the coil).

 

[Pipes]

@zky42 If that is copper foil, it looks pretty close to some critical areas that may not even be protected by your BMS!.

Yes, that is copper foil I have installed on the Skellys. The spacing looks closer in the picture but in fact has 2-3mm clearance from the battery posts. Its sticky back tape so will not shift. It is needed to shield the batteries from the eddies as were causing the BMS to trip. Found it to be needed once I changed over the BMS board to the smaller one.

 

[zky42]

@rz
Thanks for the welcome.
This is actually just the perspective in the photo. There is enough space in between.

 

[samlant]

This will depend on it's construction, and a supply that can't handle the load gracefully will likely result in.. a blown MOSFET. The ZVS modules may often have MOSFETs that just aren't suitable for the job, and cause a fuss very easily.

What power supply are you trying to use?

I purchased and received this power supply.

High current switching should rather be left to a MOSFET (module)

When you say that a MOSFET module should be employed instead of a switch due to potential "early failure"---if I may call it that---is that referring to something like the FET switch that Pipes has linked to on his parts lists throughout this thread? How the heck would this be wired? i see the terminals' markings on pics but seems to work similar to a potentiometer to my brain in the form of a PWM module? If so, how would that be helpful? Maybe that's the tuning to utilize 60 watts you mentioned?

A 12v 5A switch is VERY marginal. It may work as an only switch if you've tuned your IH to operate below 60W,

What do you mean by marginal? and tuning as in spacing out the coils to reduce current load? Trying to ensure a longer-lasting IH, thanks for all your advice
EDIT: Oh! 12v 5A SWITCH! I was reading 12v 5A power supply! yes that would be marginal. I have a 12v 30A switch I see you meant that it can only handle the rated power and not more, I understand

Hmm, you term "high-rise" has me a little confused. Works in houses too!
I think your talking about the transition time or rise time for the voltage to be presented. Meaning the voltage must be switched to the "on" state quickly, which is pretty much any switch will do. The voltage must also be high enough get the oscillation started between the push/pull FET oscillator. Should not be a concern for these drivers as long as you stay over a 9 volt setup.

You interpreted me correctly: getting to the intended voltage quickly enough to start the oscillations. With this DC switch, would a FET module be necessary?

If the board is shorted meaning the FETs are shorted, the supply will kick into protect mode right away and usually pulsates. The led on the driver board may also dimly flicker at the same rate.

This is exactly the issue and what's going on. I don't think the coil was being heated up enough (no switch, just directly wired from power supply to ZVS module) so I thought maybe there was something wrong with the wiring or something, so I left it on for a couple minutes to see if it needed a warm-up time, and then after that I thought maybe swapping + and - might do something (lol, desperate times call for stupid and desperate measures)

 

[kazenine]

i tried to made 1 heater with
- zvs 5-12v
- momentary trigger
- on / off button
- mosfet
So, can i use a 12v 3A for this heater ?
i saw everyone use 12v 6A for this.

sr, im not good at english

 

[nachooo]

Finding enclosures is difficult I have been thinking even in 3d print with a heat resistant filament material as a perefect solution to this problem

 

[Pipes]

@samlant, that switch should work but not ideal for the task. A FET is a much better way for a couple reasons. No contacts to wear, out but more importantly, less contact voltage bouncing happening which only gets worse as the contacts wear.
Your problem could be two possibilities. Either all is fine and it's just the power supply not adequate which has my money on it. This has come up many times now. A supply rated at 5 amps is border line rated but what's worse, and no way of knowing, is how the protection circuit behaves. The supply I have is the only 5 amp unit that I, myself have found to work fine. I have tried about 5-6, units rated at 6 amps to find they do not work as well. The protection circuits are designed differently and I assume it's how fast they kick in that makes the difference. Something like a slow blow fuse compared to a fast blow. There is a momentary current surge when first turned on which kicks the fast blow supplies into protection.
The other possibility is that the FETs are truely shorted. Only remedy there is replacing them. If you are seeing the blue led on the driver board flicker with any brightness at all, I'd say the FETs are likely OK...?
I may kick myself here for this suggestion but here goes. As a test only, you need a 12 volt that will not back down. If you have a car battery at your disposal, it will certainly not give you protection. If you do a temporary but secure connection to it, you'll get your answer real quick. Once wired with your switch and polarity is correct, (triple check) and when you press the switch, either the blue light will come on and no smoke from under those big ass choke coils indicating all is good. Or you will immediately see/hear/smell the FETs burning up under those coils. No need to watch the fireworks any longer as they are toast.
If all works, you need a different supply and get geared up to replace the big ass switch down the road.

 

[samlant]

@Pipes Did what you said with a 12v agm battery and it smoked. I recall when I had just received the zvs module seeing the blue led blink and not stay solid as soon as I put a load into the coil, so the power supply may not be adequate like you said. I'll probs order a Lipo battery and charger soon.

If I wanted to incorporate a MOSFET in order to not have to deal with contacts degrading, but still want the/a switch, where would I wire in the switch and what would i put in the PWM solder spot of the FET switch?

 

[Pipes]

 

[RUDE BOY]

I'm loving my portside mini so far and I've been using it daily now But I've run into a problem with my nanavong. The cap get's stuck on the vapcap after using it with the PSM, since it has the newer tip when you push to engage the switch the edges of the tip gets wedged between the sides of the cap and the plate that clicks... First couple of times it was just a pain in the ass but now I can't remove the cap from the vapcap Works fine with the SS tips from the Ms and the old Ti tip from my OG woody but the newer tip isn't doing very well.

Anyone else have this happen? Am I alone here?... I tried different caps with the new Ti tip and they all do the same and get stuck after engaging the switch...

 

[samlant]

@Pipes I think I understand that. The battery is directly connected to the BMS module, which gets fed to the FET board while also having a kill "switch?" and the charging port connected to the + and -, and the switch gets attached to the one Trig/PWM contact on the FET, and then the output gets wired simply to the driver and coil.

The BMS is used to prevent overcharging each cell, over-discharging, sets max current @ 10A, and balances the cells (I think I got that right?). Would it still be necessary if I use an already balanced LiPo charger? Also, B+, B-, B1, and B2 are for the four balancer cables, while the P+ and P- are the outputs going to the FET board? What about the two power cables? i think i see them go in B+ and B-?

 

[Newcastle]

I left my power cord at the Hotel this weekend. Any suggestions on a replacement?

 

[Pipes]

Amazon

 

[Newcastle]

Does anyone have a link? I dont know what to look for. They all look the same to me.

 

[Pipes]

@Pipes I think I understand that. The battery is directly connected to the BMS module, which gets fed to the FET board while also having a kill "switch?" and the charging port connected to the + and -, and the switch gets attached to the one Trig/PWM contact on the FET, and then the output gets wired simply to the driver and coil.

The BMS is used to prevent overcharging each cell, over-discharging, sets max current @ 10A, and balances the cells (I think I got that right?). Would it still be necessary if I use an already balanced LiPo charger? Also, B+, B-, B1, and B2 are for the four balancer cables, while the P+ and P- are the outputs going to the FET board? What about the two power cables? i think i see them go in B+ and B-?

Your getting a handle on it. Only thing off is that this BMS does not balance the cells. It does however, monitors each cell and will go into protection if too far off or if one cell gets too low ahead of the other cells. Generally they will balance themselves after a few cycles if all in the same condition. Of course, if you have an good external 3S charger, wouldn't hurt to periodically do an external charge.
Anyway, it's the protection you need from the BMS. They also keep the cells from over discharging which is very important to the life of the batteries. If going to use battery power, the BMS is VERY important. Consider the car battery procedure for confirming it was indeed shorted FETs. If not prepared for the results, that's what you would have gotten with 18650s without protection. Would have being a scary scenario.
If your using a supply which has protection, it will suffice.

 

[RUDE BOY]

Does anyone have a link? I dont know what to look for. They all look the same to me.

Click on where it says Amazon in pipes post.

 

[samlant]

Your getting a handle on it. Only thing off is that this BMS does not balance the cells. It does however, monitors each cell and will go into protection if too far off or if one cell gets too low ahead of the other cells. Generally they will balance themselves after a few cycles if all in the same condition. Of course, if you have an good external 3S charger, wouldn't hurt to periodically do an external charge.
Anyway, it's the protection you need from the BMS. They also keep the cells from over discharging which is very important to the life of the batteries. If going to use battery power, the BMS is VERY important. Consider the car battery procedure for confirming it was indeed shorted FETs. If not prepared for the results, that's what you would have gotten with 18650s without protection. Would have being a scary scenario.
If your using a supply which has protection, it will suffice.

Bought a cheap 3S balanced charger, and confirmed that the FETs are shorted. Received another ZVS just this afternoon but I blew that one too (Maybe it was because the terminals where the coil was inserted werent screwed down?). I dunno, I didnt mess up the wiring, it was hooked up to an auto agm battery, so maybe it was a case of thermal runaway?? Other than that, what i think is the coil may not have made good enough contact with the terminals of the driver. I pressed the button for about 30 seconds, with the vapcap in it, didnt touch the sidewalls or anything. It didnt get hot at all really eother, but the two coils on the driver got warm What on the planet am I doing wrong?? Im not braindead, but I think Im missing something here. Would a pic of my wiring help?

I have a battery, the negative running to thw ZVS driver and the positive going through a 30A switch then to the driver. Super basic. I guess I need to guard against thermal runaway then.

 

[Newcastle]

Thank you @RUDE BOY ....Thats a neet trick...

 

[Pipes]

(Maybe it was because the terminals where the coil was inserted werent screwed down?)

Bam, that'll do it in an instant. I have said this a few times now. Those blue connectors suck and should not be used for the work coil. For a connection you only get one crack at, solder is highly recommended. Even some sites that sell them recommend direct soldering. With no work coil there is no oscillation and therefore a DC short circuit.
Dealing with mosFETs can be very frustrating when wiring up tuned circuits that use them. They have no forgiveness at at and can be really annoying. On top of that, these ones are very poor quality and die easy. Better ones are cheap enough though and you should get some extras.
Good luck, keep plucking away and you'll be really happy when all is said and done.

 

[samlant]

Bam, that'll do it in an instant. I have said this a few times now. Those blue connectors suck and should not be used for the work coil. For a connection you only get one crack at, solder is highly recommended. Even some sites that sell them recommend direct soldering. With no work coil there is no oscillation and therefore a DC short circuit.
Dealing with mosFETs can be very frustrating when wiring up tuned circuits that use them. They have no forgiveness at at and can be really annoying. On top of that, these ones are very poor quality and die easy. Better ones are cheap enough though and you should get some extras.
Good luck, keep plucking away and you'll be really happy when all is said and done.

Fantastic, I feel better already hahaha My Hakko soldering station gets in on Wednesday, Ill then tear apart both drivers and use the two good mosfets (1 from each) on one board and Ill check to order some more. Off the top of your head do you happen to know what mosfets they are, or ones thatll work (will several fit the application?)?

 

[Pipes]

They almost always both go. I've never had good luck just changing one out. Regardless what they seem to measure. Usually turns into changing back and forth a few times before you say fuck it and change both at once with fresh ones... Taking the factory mounted ones off is easy compared to taking ones back off that you already replaced. Usually will break board traces and end up with little messy jumpers.
You'll find those big coils will twist enough to let you get your iron on the FET legs.
Good luck!

 

[Dynalowrider]

@Wissmu, check out Red Rock Outdoor Gear, Media Pouch #82-011. I have one and it will hold the Mini and plenty of room for what ever you need, VapCaps, lighters, whatever. It has Mollie suspension or belt loop. Nice case, looks like a camera on your hip. Doc

 

[frankbhelger]

https://i.imgur.com/a6NQc2c.jpg
https://i.imgur.com/gWc3Dk3.jpg

here is what I am thinking: